Simple construction methods without elaborate machining techniques, as well as "user friendly" electronic control components, are features I attempted to incorporate into this project.
Thanks CNC Zone & to the many who have posted information, plans, answered questions as well as given opinions.
The table top was first squared, levelled, & tack welded on the shop floor.
Legs (2" square tube), casters, & leg spreaders (1" std. pipe) were added.
Welding of these components was then completed.
More to follow.
Weldtutor

Since first seeing John K's idea over 2 years ago, I have also been having 'Pipe Dreams' but of the plasma kind.
Jgro's plans were consulted, as well a reading & studying hundreds of posts here & on other sites.
The free plasma table plans by Mike Laws, available for downloading here at CNC Zone
were what finally gave the inspiration to attempt making the dream a reality.
Being a fan of KISS engineering I thought, with a few modifications 'I can build that.' I have a chop saw, a drill press, & a welder. If needed the big hammer as well as the disc grinder can be put into play.
Download the plans, print them out, study them, ask questions, make drawings, change the drawings, plan some more, ask, scheme, dream etc. Yes, 'I can build that.'
And so I started....................

Off to a good start, have you decided on a plasma cutter model yet?

Hi Trubleshtr
I plan to use a Thermal Dynamics Cutmaster 51 plasma cutter. There are many good machines available from the various manufacturers. I had it narrowed down to a choice of 2 manufacturers.
It would seem to be a matter of indivual preference, based on needs, after doing a search of what the market has available.
Thanks for your interest.
Weldtutor

The 1st photo shows the collars used to hold & allow for adjustment of the X axis rails.
In the 2nd, an angle mounting bracket has been welded to the collar. Slots in the brackets will allow for additional adjustment of the brackets & hence the rails. Brackets will be located at each of the 4 corners of the table top.

Here are some photos that weldtutor resized for me. Hopefully they will serve some inspiration to anyone attempting to build their own plasma table. It can be done!

Thanks for posting the photos Trevorhinze.
Your design is one that is very workable and should help others to take the starting plunge.
The earlier post of your partially built machine certainly was encouraging for me. The compact work area of 2' X 4' would be attractive for a lot of home shops.
Weldtutor

The X axis mounting bracket that was in post #5 above, is seen here fastened to one of the table corners.

A shim was located between the table edge & the bracket to allow for additional adjustment of the axis rail during fabrication.

The table is also shown with the gantry positioned on the X axis rails.
WT

Angle iron, 1/8" X 1-1/4" X 1-1/4" was used to hold the bearings for each axis.
The various sets were shimmed differently depending on the axis rail sizes.

X = 1-1/4" Nominal Std. pipe
Y = 1"
Z = 1/2"

The confused sales clerk at the sporting goods store told me the bearings were only for use with real inline skates!!! (chair)
Weldtutor

LOOKING GREAT? It is cool to see all the new plasma being built. As these get built, we should compile pictures and plans in one place. It would give a lot of options for some one wanting to build a table.
Keep posting pictures.
mike

Thanks for the comments Mike, & to others, feel free to add yours or ask questions.

By doing a search for "Free Plasma Table Plans" you will be able to download the plans that Mike has generously contributed. Or click this link-->http://www.cnczone.com/forums/showthread.php?t=14488&highlight=free+plasma+table+plans
Weldtutor

The control box pictured is from Trevorhinze plasma table in post #6.

Contents include Linisteppers mounted on the large heatsink, power supply unit, cooling fan, a nice air filter etc.

These photos give an overview of what the table & gantry is starting to look like.

The 2nd. shows the back side of the gantry with the Y axis carriage sitting in place.

The Z axis will be of the "floating" variety.

This puts an upward lifting load on the Y axis. If routing was the application for a design of this type, similar vertical movement would tend to take place.

An adjustable "anti lift" bearing as shown on the back side of the Y axis carriage is the solution used here.

The first photo shows the front side of the Y axis.

Photo 2 is a close-up of the Y carriage & the 3 axis rails used.

These pictures shows what happens when you give a master builder some metal.
mike

Thanks for the kind words Mike.

A satellite dish was the donor for a lead screw & brass nut.

This one had a 20:1 speed reducer attached that is likely a bit too much for any of the 3 axis on this machine. :(

Second photo shows the Z axis carriage with the brass nut located within it.

Belt drive mechanism is shown in 1st photo.

Control box shown has an arc start relay at top left & linisteppers at top right.

Two power supplies, with a 12V unit at lower left.

Sample cuts. Eagle about 7" wide .250" thick.
Biker 15" wide 14 ga.

looks good, anymore pics of the whole machine together? how do you actuate the trigger on your plasma gun?

Hi Trublshtr & all,
I'm just a bit farther along on the project than the pictures shown back in post #15.

The Z axis is almost completed now. I'll try to add a picture of it later, or was there some detail you wanted to see better?

Electronics, motors, mechanical cable drives etc. have yet to be added.

A relay will actuate the gun trigger circuit to initiate the arc.

This photo shows the Z axis carriage mounted on it's guide rails.

The torch mounting plate is at the bottom

The Dog (Greyhound Variety) brought a nice shiny Thermal Dynamics Cutmaster 51 to me over the weekend. :banana:
This delivery was made possible by the co-operation of 2 fellow CNC Zone members.
Thanks guys! :wave:

NICE, now your making me jelaous ;)

NICE, now your making me jelaous ;)
Sorry, I really didn't mean to make you feel that way! :violin:
Maybe if you click on the picture of the plasma machine, then expand it to full size, it will seem like the machine is going to jump out of your monitor & into your shop.

It sure would look nice sitting by that machine of yours with the great rails! (DROOL, DROOL) :cool:
WT

It sure would look nice sitting by that machine of yours with the great rails! (DROOL, DROOL) :cool:
WT

I was thinking of it attached to my industrial robot :D

It sounds as if you have more "toys" to play with than I knew about.
Now the jealous one is at this end. :mad: Do you have it operational?
About 15 years ago, at my former employer, I worked with a 5 axis Fanuc S1R robot. It was equipped with a GMAW (MIG) package.
That was so much fun I would go to the workplace evenings & week-ends to (play) & learn more about it.
At the time I had a Max 40 plasma arc machine ready to connect to it but the employer :nono: decided against it. His loss I believe.

It works but it is a re-ject from the early 80's and use's very basic programming. It's a small 4 axis unit. I have been actively searching for a new way to "drive" it. I think 'linx' is the only option, but I don't have the time to explore it. The time it takes to program it to cut a simple 'word' right now takes hours. It would be good for a repeatable task. That and my mini mill (non-cnc) are about the extent of my toys.

Robots are indeed fun, I am fortunate at work to be able to play with all the new modern ones. I think a plasma cutter attached to one maybe a good option for this little guy, just don't know what I'd build with it yet.

The first picture is of the control enclosure built by Mlaws CNC.
It contains 3 Gecko 320 drives, power supply etc.

Servo motors will be used with the wiring harnesses shown.

Still not ready to "make sparks" yet. :tired:

i was just readign your thread again and saw this part (air filter for your old case) thought that idea is good.. are you going to add that to your new case? right now i forgot if air is flowing inside or not

it seem really good idea to use those type of filter to block any bad stuff inside the case

The credit for the air filter inlet idea goes to Trevorhinze, as that picture is of his controller. :idea:

Metallic "dust" or "smoke" created by plasma cutting could cause another kind of smoke in the electronic area!

Our Mlaws enclosures have a nice feature with air inlets in the bottom & holes in the false bottom.
This would seem to be a natural area to place some air filtering material. Fibreglass furnace filter material or other synthectics would be simple to install there.
WT

ahh perfect.. i will add that promptly then.. mike is currently building our enclosure system wtih full controller.. really exctied and eager to have them ready.. only biggest part that is left with my table is electronics then get shafts/gear rack and mount the motors then all little things that didnt go perfect and then cross my fingers it works :)

It might be easier to have Mike add the filtering material before he installs the false bottom.
That would save you having to remove it & any panels or connections would not have to be undone.
Not too difficult either way.

I can do that and make it so you can remove and clean from outside.
mike

Easy outside cleaning of an air filter would be another feature to include in your already great enclosure.

Sharing ideas & asking questions certainly does lead to positive results at CNC Zone!
Thanks Mike

WT

KSKID questioned timing belt drives in another thread & mentioned low cost, simplicity, ease of set-up etc as making them attractive.
I don't have first hand experience but perhaps Trevorhinze, (who has done some great cuts with his machine) or others can respond.
A seach for "belt drives" might yield worthwhile results also.

I have recieved some questions about my Belt Driven plasma cutter of which there are several pictures throughout this thread. I will try to answer them here so that others who are wondering about the feesability of a belt drive may know what I have found out. I have only used the belt drive setup for a plasma cutting machine, and I have no idea how the setup I used would work for a routing machine that would see much higher cutting forces. Overall I am very pleased withe my use of timing belts to move my machine. They are low cost, easy to install and maintain, silent in their operation , and very sturdy. After a couple of months of cutting they seem to be completely un affected by all of the nasty dust created by the cutting process. All in all I wouldn't even consider any other drive method for a plasma cutter except maybe rack and pinion which I found to be too costly. You will notice in the photos of my belt drive that the belts are positioned with the teeth facing down, I sure can't take credit for this idea as I found it somewhere on the web years ago, but it does a good job of keeping most of the "junk" out of the teeth of the belt and the timing pulley. You will also notice that the belt is forced over the timing pulley by two smooth rollers located to either side of the timing pulley. These serve to keep the belt and pully engaged, and they also cause the belt to engage about half of the teeth on the pulley rather that just one or two. As far as accuracy is concerned it seems to me that my machine has much better resolution than I will ever be able to take advantage of since the plasma plume naturally likes to wander and lag a little, but overall the parts I draw and cut come out to be very close to the size that I want. Overall I am very pleased with my belt drive machine, and someday when I build a larger more capable machine I will almost certinially use belts once again. Good luck to everyone who is building, or thinking about building a machine of their own!

Thanks for the nfo, i plan on going this route for my buildup, i do not plan on using my machine for routing, plasma only, mostly metal artwork so i think it would work fine for this application. i also liked the ideas to cut costs of using roller bearings or some other source of surplus rollers to use over linear bearings etc.

I tried to cut costs when building my machine wherever possible while still building a machine that would be functional. I have less than 500.00 into the machine total, though just about everything besides the stepper drivers and the power supply were used items that I had been collecting for a couple of years before I started to build the machine. When I did start to build the machine over two years ago I quickly completed the mechanical part since that wa the easy part for me. It then sat for about two years basicially untouched since I was intimidated by the electronic portion of the project, but with lots of internet studying was able to get it done. One area where I tried to save money was in the THC department. I thought that I could get by without one, but now after using the machine I have come to realize that I will need to add a THC to the machine in order for it to perform at its max capability, this has been a hard pill to swallow since the addition of a THC will basicially double my total investment in the machine, but it needs to be done when the funds will allow. As for what makes my machine move the X axis is powered by a nema 34 stepper, and the Y by a nema 23 stepper. Both are controlled by linisteppers and I am running Mach2 as my machine controller

liked how you did just a simple roller, underneath the the opposite side of the x-axis, just a roller to support the weight of the y-axis, very simple but effective., was wondering if you or anyone else had ever heard of doing a cnc router/plasma using a cantileaver setup, which would allow three sides to actually insert and remove materials from instead of being limited to just the ends., would this even be possible, i have never seen a photo of one, any thoughts?

a cnc router/plasma using a cantileaver setup, which would allow three sides to actually insert and remove materials from instead of being limited to just the ends., would this even be possible, any thoughts?

A cantilever design is subject to instability that increases directly with the distance of the cantilever. Think of vibrations or "Diving Board Effect" or bounce, at the unsupported end.

The gantry is less likely to show this type of movement if properly designed & built.

Loading of a plasma table from 3 sides (or 4) is easily done if the surface of the support slats is positioned above the table sides. Linear rails or slides would also need to be below the support slat surface.

The photo helps to explain the second part of the previous post.

Workpiece support slats are above the surface of the table sides and ends.

Side rail surface is below surface of support slats.

Loading & unloading of the table can be from either end and both sides.

thanks for photo, yeah the cantilever idea would kind of be a bad idea, need to use the KISS principle on the design of my table, i tend to put too much thought into things sometimes.

Kiss engineering is good!

I think you must be a romantic using that term to-day! ;)

Trevor, great looking project!

What would you say is the resolution of your table? When cutting a circle of of a give size, how round would it turn out? Do the start and stop points match well?

Trying to decide if gear or belt reduction will be worth the effort. :) I plan to make prototype suspension pieces so accuracy of around 1/16" or better would be about right.

David

David, Thanks for the interest. I would say that the resolution of my table is easially within the 1/16th inch that you are looking for, but the accuracy of my plasma cutter itself isn't always that good. I just have a little Hypertherm350 (27amp) and I am reallly pushing it most of the time cutting stuff out of .250 inch plate. The reason that I mention this is that with anything other than a brand new tip I get a good amount of bevel, and the direction of that bevel can change from one spot on the workpiece to the next. I have not had any problems at all with start/stop points lining up, but I do always use a .25 to.50 inch tangent leadin/leadout. I can cut out an oval 2' by 3', and you can't tell by looking at the edge of the piece cutout where the cut started and stoped, so my repatibility must be pretty good, and as I have said before the resolution exceedes that of the plasma arc itself. Good luck with your table.

use of timing belts to move my machine. They are low cost, easy to install and maintain, silent in their operation , and very sturdy.
The timing belts & pulleys appear to be close to the XL series/size.
Are they that size, or something different?

The belts/pulleys on my X(long) axis are in fact Xl series Gates parts, the belt and pulley on the Y(short) axis are of an unknown type, I got the belt and pulley out of a large printer I tore apart a couple of years ago, they are slightly smaller than the XL parts, but they seem to work well.

First photo shows the Z axis motor installed. (2 more motors & drives to go)

Plasma torch is located in floating mounting plate.

Looks like you have made quite bit of progress. I will be interested to see how your floating Z axis works when you get your machine up and running. Those little rollers look familliar, are they the little ball bearing rollers that are normally used for material conveying? Seems like a good low cost solution if it works. Keep up the good work.

Those little rollers look familliar, are they the little ball bearing rollers that are normally used for material conveying?
Yes, they are used for conveying. Most listings refer to them as transfer bearings.

Some have a stud incorporated for mounting or others like the ones I used, a flange designed for surface mounting with a fastener.

This floating Z axis design is from the Mlaws1172 plans mentioned earlier in the thread.

Bearings of this type were also used by "Accuratemike" for his CNC oxy-acetylene cutting torch. For this application the transfer bearings rode on tubing for the X & Y axis movement & is pictured elsewhere, here at CNC Zone.

looking real good
mike

nice work

Thanks for the comments guys. :o

Photo shows the gantry in the "parking lot."

This was accomplished by building the table top, with extended side pieces, and Z axis rails also are the longer length.

A useable work or cut area of 60" by 49" is available.

weldtutor,

really like your idea of using off the shelf roller bearings for your
x,y, z axis, was wondering how well everything works with
this setup, any noticable drag?, would like your opinion on
your selection.

also, curious what do you plan on using for your X & Y Axis drive?

and for your Z-axis what kind of threaded rod/nut are you using?

thanks

Thanks for the kind comment & your interest.

The roller (skate) bearings move very smoothly on the pipe axis rails. This was one of the pleasant rewards I experienced when the X & Y axis were first assembled. I probably rolled the gantry back & forth, by hand, for an hour or more. It seemed like it was "floating." :banana:

The Z axis has a 3/4" 6 TPI Acme threaded lead screw with a matching brass nut. This is from a satellite dish control arm as shown earlier, in post # 17 of this thread.

Currently the X & Y drives are being fabricated & assembled. These are #40 roller chains. A jack shaft will provide drive force to both sides of the X axis. More on these drives to follow, in future posts. The photo shows some of the hardware for the drives & their sub-assemblies currently completed.

curious to know, what the determining factors were for you to decide on the drive system that you have selected for the X and Y axis, still trying to decide which way i should go, i like the direct drive blelt setup, less moving parts but would like to weigh all my options before deciding on one in particular.

what the determining factors were for you to decide on the drive system for the X and Y axis,
Availability from stock, standard components, and 2 local suppliers were the main factors for me.

I also find chain & sprocket drive systems easy to work with & modify speeds.
These drives will provide the necessary power transmission & accuracy for this application. :)

Cable drives were first selected, but various pulley sizes, bore sizes & bearing types were difficult to source after a few initial purchases.

Ball screws & rack/pinion drives usually got responses like "we could order them for you."

Your mention of timing belts (with cog pulleys) certainly is worth consideration especially if suitable "surplus" items can be located. Again, suitable off the shelf items were not found by my searchs.

I am quite interested in this machine, but I am still unable to download the plans offered. would there be any way to get this info in my email? the reason I ask is that I am at work, and the boss doesn't like new programs being downloaded to the comp. anyway, the machine looks great, quite ingenuitive.

Welcome to CNC Zone & thanks for your comments. :wave:
I am still unable to download the plans offered. would there be any way to get this info in my email?
The link to the plans offered, by Mlaws1172 is back in post #11.
It is not a program, but one compressed file.

You will need a CAD program that can read and print the DXF file format the plans are in. The thread with the plans makes a recommendation for a free CAD program that is available.

If you send your Email address, by PM, to the plans author you'll likely get them sent to you.
The Mlaws plans were a great help to me in planning my machine, although I did not follow them exactly.

thank you for your help, your machine looks like its coming along nicely. is there any advantage to using chain drive verses belt drive??

is there any advantage to using chain drive verses belt drive??
The choice of chain drives for my application was made largely on the local availability of suitable components.

Other selection criteria might involve:
-cost of timing belts & pulleys Vs chains & sprockets.
-durability of components for the application.
-builders familiarity with materials chosen.
-access to machining/fabrication equipment.

A properly designed & built system using timing belts, certainly would provide the needed positioning accuracy.

The first 3 photos are of the Y axis drives.

Last photo is showing sprockets on the jackshaft to allow both sides of the X axis to be driven.

Great job - great pictures, this is what the forum is all about (I hope), sharing ideas. Bruce if your computer for the plasma is close to internet access, we can do a setup at the chat room here.
mike

OK, the pictures are worth a thousand words, see what you are doing with your chain drive etc. now, that gear box looks like a hefty piece, how much does that thing weigh?

do you plan on using this cnc machine for a router as well?, if the answer is no, why are you driving both sides of the X-axis?, can you explain the advantages of this other than the additional force you gain for CNC Router processes?

still trying to decide on the route i want to go with my design.

thanks for the pictures, looks like yours is coming along really well.

Great job - great pictures, this is what the forum is all about (I hope), sharing ideas.
mike
I sure learned a lot from the posts and pictures you & others have contributed here.
Providing the facility for sharing is where CNC Zone is an excellent resource.
I'll PM you regarding a set-up chat.

OK, the pictures are worth a thousand words, see what you are doing with your chain drive etc. now, that gear box looks like a hefty piece, how much does that weigh?
why are you driving both sides of the X-axis?, can you explain the advantages of this

I'm glad the pictures helped to provide an understanding of the drive methods used. Whenever I can save a thousand words, I'll grab my camera. :)

The speed reducer is listed at 29.5#

The machine is adaptable to routing, due to various features incorporated into it's design which prevent "lifting" of the 3 axis resulting from the forces generated by this action.

Steady movement of the gantry along the X axis is necessary for both routing and plasma arc cutting. The method I chose to provide such steadiness is using dual drives.

Other designs have achieved the needed results from:
-dual bearing surfaces on one or both sides of the gantry,
-"T" shaped gantry bases with the top of the "T" much elongated to allow a greater distance between the bearings,
-stabilizing cables & pulleys around the gantry,
-center drive of gantry rather than end driven,
-use of much narrower table width.

The first 2 photos show an end & also a side view of the X axis drive & speed reducer.

Third photo shows orientation of each of the axis.

Attachment of the electronics & work supports are to follow.

Making Mach Move it will be the next challenge!
(Set-up hints appreciated,Thanks) :)

DANG !!, thats alot of chains....question ???.....what happens when the chains start wearing and ultimately stretching out of their original shape, i have had a few motorcycles, know it all to well about having to retension chains., won't this diminish the accuracy of the machine over time.

DANG !!, thats alot of chains....question ???.....what happens when the chains start wearing and ultimately stretching out of their original shape, i have had a few motorcycles, know it all to well about having to retension chains., won't this diminish the accuracy of the machine over time.

Another thing I'd like to add to this is, what about contamination from Plasma dust?
From my experience with Plasma cutters, the dust gets everywhere.

Both the X & Y axis have been constructed with allowances made to readjust the chain tension to maintain positioning accuracy.

Each side of the X axis has a threaded connection at the end of the chain for tensioning.
The idler sprocket on the Y axis is also adjustable to accomplish this.

Metallic "dust" referred to is resultant from the plasma process, not the drive method. Chains will shed this material more readily than most other designs.

Plan your work, work your plan.

I used chain on all three axis and will be posting some pictures shortly. I used 200 pound die springs to keep chain tight as for the chain getting longer from wear if you look at most chains they are traveling 20 to 30 times faster then slow speed of axis movement so for every hour you run motorcycle I will have to run my plasma table 20 hours to have same wear, for a hobby machine it will take a very long time to wear out to the point of replacement and chain is cheap also using chain made building table very easy.

Thanks for posting the positive remarks Beetman05.

That's what makes CNC Zone the great resource that it is.

Help & encouragement is always appreciated by those here!

Your future picture posts will provide inspiration to others wishing to build their CNC projects.

I didn't mean to sound negative, but was just wondering if it was something you'd considered. I know chain drives quite often have to endure some abismal operating conditions, but getting covered in metallic dust isn't an everyday occurence for chain drives.

The project is looking good though, and I may borrow one or two ideas once I get round to building my plasma table somtime next year (my sketches are buried in the previous posts).
At the moment I'm concentrating on retrofitting a mill, as I figured the mill would be handy for making bits for the plasma table.

(my sketches are buried in the previous posts).

Yes, I've seen your sketches from about 2 years ago, and choose not to comment on them!
If you wish to continue in your previous tone please use a PM or other method, as suggested by the message guidelines.
--------------------------------------------------------
Some Create, Others Don't

The roller chain tensioning devices incorporated into the machines design are pictured here.

Threaded adjusters were used at the end of each of the X axis drive chains.

Shims are the allowance made for adjustment of the Y axis idler sprocket mounting bracket.

Looking good!
Would like to see it running :)
Creative thinking with those chains, and I think wearing will be considerably low with those speeds.

Keep up the good work, and keep us posted :).

Friendly Regards,
Erik

I used chain on all three axis and will be posting some pictures shortly. .......... for a hobby machine it will take a very long time to wear out to the point of replacement and chain is cheap also using chain made building table very easy.
Great pictures of your project! :cheers: Thanks for sharing.
Check out the Photo Gallery for the pictures Beetman05 has uploaded of his plasma table!

See post #18 of this link for the pictures.
http://www.cnczone.com/forums/showthread.php?t=14743&page=2&pp=15

Bruce
I had missed your last pictures. Looks like you should teach welding.:)
Just keeps looking better,now if we can get those controls working.
Mike

Thanks for the comments Erik.
I'd also like to see it move. :confused:

I'm sure the controller will do a fine job Mike.
My settings in Mach3 are likely in need some adjustment.

As mentioned in my PM, the keyboard arrow keys & buttons in the MPG screen show position changes on the DRO's, but the motors are not moving.

This link (as of todays date) still has about 90 photos of the plasma arc CNC table being constructed by DanOSB & associate.

http://www.ubcustom.com/cnc/

Lots of good ideas pictured there.
Thanks for sharing your link.

While connecting & testing the various controls shown in the first photo, it was decided that a more convenient layout was required.

The solution.............. a roller cabinet with keyboard tray etc.
Just another application of KISS engineering! :cool:

___________________________________________
"I can build that."

Like the cart!!
mike

Thanks Mike,
I decided to do something that I was pretty sure I would succeed at, ;) for a change of pace.

The cart does a fine job of holding that fabulous electronic enclosure you built as well as making the controls convenient to see & use.

The first picture is of the control enclosure built by Mlaws CNC.
It contains 3 Gecko 320 drives, power supply etc.

Servo motors will be used with the wiring harnesses shown.

Still not ready to "make sparks" yet. :tired:

i was wondering if you could go into more detail on your electronical part of your setup, interested in your setup by Mlaws including cost, stepper size, etc. etc.

thanks

more detail on your electronical part of your setup, etc.

I'm somewhat "electronically challenged" so here goes!
It's a big black box with a whole bunch of stuff in it, like boards & a lot of wires & thingys & do-dads & little red & green lights etc. :confused:

The main power source is built around a toroid transformer, with a capacitor & bridge rectifier. It has a 44 VDC output.
In addition there is a 5V & 12V supply for the Gecko 320 units, & various cooling fans etc.

Relays are used to activate the plasma arc initiation as well as for control of an auxiallary 115V receptacle that is planned to be used for a ventilation fan.
Also housed in the enclosure are a charge pump & breakout boards for connections to the 2 parallel ports in the PC controller. The second was added to allow for axis jogging by a joystick.

The motors are Electro-Craft brush type servos (not steppers) with Renco 250 line encoders.
45V max.
4000 RPM
180 oz-in max peak torque

The wiring harnesses with connections at each end make for easy set-up or relocation of the system.
(Nice touch Mike!) :)

Mike, who put the system together for me monitors this thread, & can likely add to this as well as help with other questions you might have. Costs of course depend upon exactly what you have incorporated into the system.

Thanks for your interest.

Bruce is my tester (not by choice). I am putting together a few systems. For a system with 3 axis the price is $1850 and includes the following.
3 ea.- Ametek 39V 12 amp. 600 oz. in. motors
3 ea.- Gecko 320
3 ea. - Renco 1000ppr encoders
1 ea. - 40 VDC 25 amp. power supply
1 ea. - stainless steel enclosure
1 ea. - 12VDC/5VDC powersupply
1 ea. - parallel board 1
1 ea.- parallel board 2
1 ea. - servo monitor/charge pump board
3 ea. - 25' wiring harness with connectors
6 ea. - limit switches
1ea. - cable for plasma connector on one end
1 ea. - joystick
buttons,switches and connectors
assembly and testing
Everything is new or nos, except maybe the limits. The limits are heavy duty roller switches and I think they are new.
I have parts for a few of these. I am also putting boxes togethor with CandCNC parts which are great boards. When my parts are gone these are the parts I will use.
Mike

Bruce is my tester (not by choice). I am putting together a few systems. For a system with 3 axis the price is $1850 and includes the following.
3 ea.- Ametek 39V 12 amp. 600 oz. in. motors
3 ea.- Gecko 320
3 ea. - Renco 1000ppr encoders
1 ea. - 40 VDC 25 amp. power supply
1 ea. - stainless steel enclosure
1 ea. - 12VDC/5VDC powersupply
1 ea. - parallel board 1
1 ea.- parallel board 2
1 ea. - servo monitor/charge pump board
3 ea. - 25' wiring harness with connectors
6 ea. - limit switches
1ea. - cable for plasma connector on one end
1 ea. - joystick
buttons,switches and connectors
assembly and testing
Everything is new or nos, except maybe the limits. The limits are heavy duty roller switches and I think they are new.
I have parts for a few of these. I am also putting boxes togethor with CandCNC parts which are great boards. When my parts are gone these are the parts I will use.
Mike

Mike,

that price sounds really resonable considering everything thats included + labor/material to put it all together, i have decided to start out small and build a CNC X1 Mill first, just want to get my feet wet and get started and work my way up to a nice CNC Plasma cutter later on., have already ordered my mill, i would love to go with a servo setup on it, but feel it will not fit my budget currently., i plan on using this mill for cutting of aluminum up to 1/2" thick, plan on end milling quite a few 1" and 1.5" diam circles and ovals, would like yours or anyones feedback on what i can expect for accuracy using a stepper setup perhaps 280 oz. with the hobbycnc drivers., what i am most concerned with is any overlap/mismatched edges once the hole has been completed, will the stepper setup provide me with a smooth hole?, i am not too concerned with high production/high feed rates.

you have come to the right place for help. But I am not the guy to give you advice on that. I would contact Dan Mauch, Tom Claude (CandCNC), Art (Mach software),Mcguyver and there is alot of others on the zone. Fine someone whos advice you trust and stick with them. Along with alot of help you can get alot of opinons. This is not bad but it can make things a lot more complicated than it really is.
I wish I know about milling and lathes. Have fun
mike

This link should provide you with lots of ideas, if you plan to build a plasma arc cutting table. Lots of pictures with some especially good close-ups of bearing assemblies.

http://www.solsylva.com/cnc/1cnc54.html

It's built for routing although easily adaptable for plasma cutting.

I thought it was about time to introduce myself as i have been a silent observer for quite awhile now.
I have been reading alot of your posts and trying to digest the imformation you all are generous enough to share. I have copied Mlaws plans (hope you dont mind Mike) and have decided to build my own plasma table. probably be a little while before i get started though due to some flooding problems at my place which need to be attended to before the monsoons hit this year.
I have also checked out Beetmans chain driven machine pics and am really impressed maybe ill combine the ideas along with mikes and the weldtutors.
I have no cnc background at all but some electronic and automation experience, unfortunatly not much servo though.
which leads me to my first question about the ametek motors which seem to be popular. surfing the webb i have found quite a lot rated at 38vdc 900 rpm
permanant magnet motors. these appear to be three wire. I believe the gecko drives are for brushed servo motors. Am i looking at the wrong thing??
keep up the good work regards Mike.

I thought it was about time to introduce myself as i have been a silent observer for quite awhile now.
I have been reading alot of your posts and trying to digest
Welcome Mike.

With your background a CNC plasma cutting machine should be simple for you to build.

Mlaws, Beetman, myself, as well as many more, have all posted information here to share with yourself & others. There is a great knowledge base here at CNC Zone that has helped me a lot with designs & ideas.

The 'other' Mike has more experience with them, so I'll pass & let him answer the Ametek motor questions for you.

my first question about the ametek motors which seem to be popular. surfing the webb i have found quite a lot rated at 38vdc 900 rpm permanant magnet motors. these appear to be three wire. I believe the gecko drives are for brushed servo motors.
Am i looking at the wrong thing??

Maybe others will answer your Ametek servo motor questions.

Can anyone help? :)

the ametek motors which seem to be popular. surfing the webb i have found quite a lot rated at 38vdc 900 rpm.
These motors have been used on plasma table builds by DanOSB, Mlaws1172, & Smilewizard as shown elsewhere in posts here at CNC Zone.

Most of the resellers do not have the encoders included in their listings.
To use the Gecko 320 drivers you will need to attach encoders to the motors.

The 3 wires you mention on the Ameteks are for DC+ DC- & the 3rd. is fastened to the motor frame.

Thanks weldtutor thats a big help, i realize i will need encoder feedback,
and have already checked out the same type as mike laws used,
I will probably start to get my components together soon, dont know when ill get the time to start on the mechanical though.
do you have any pics of the things you have cut on your machine?
talk at you later
Mike.

I will probably start to get my components together soon, any pics of the things you have cut on your machine?
It does take some time to get all the bits & pieces together. Carefull planning certainly is important.

No pics of cuts.

There is currently an active thread in the METALWORKING "General Machining Discussion" forum, started by Lakeside, requesting part & art files etc.
You might want to check this to see what others are contributing.

This was sent to another member by PM in response to a request to provide information for building a similar table.

Congratulations!
Great news to hear that you have started on your CNC plasma cutting table. I'll be interested in following your progress when you post information & pictures & hope your build is as much fun for you as mine has been.

My X axis rails are made of 1-1/4" std pipe. I cut them about 8" longer than the table sides to allow the gantry to travel far enough for full cut area of the table top size.
The adjustment collars are 2-1/2" square tube, with 5/16" bolts/nuts as adjusters.
The shorter Y axis rails are of 1" std pipe with adjustment collars of 2" square tube.
Z axis rails are 1/2" std pipe with 1-1/2" square tube collars.

The picture in my build log shows the lengths of the various bearing carrier angles. The material is 1/8" X 1-1/4" X 1-1/4" angle. The bolts to mount the 8 MM I.D.skate bearings are 5/16" dia. Use care when drilling the hole positions & then use washers to adjust the bearings to have the most surface contact area on the rail surface. (Makes more sense when you are actually bolting the bearings to the angles.)
WT

WeldTutor --- your thread sure has given me a lot of Inspiration and confidence to start of my DIY Plasma.
Can’t help myself congratulating you on two fronts……. A great Table buildup and a great thread to ..Cap it all. Excellent for New b’s (like me) and for those who would like to build plasma with a tight budget. The contributions you managed from so many knowledgeable people were gr8 too.
Now that you would have run your plasma for some time I would like to ask you a few questions.
Here they come…..
You have used a pipe for the axis and supported the x axis at its ends only or have you added supports along its length. Lots of folk are worried about the harmonics & vibrations flexes that steel could create even on a rigidly supported rail and recommend some kind of Aluminum back up to dampen the vib effect. What’s your experience been on it?
What’s the max speed at which you have been running your torch?
Does your pillows have the tendency to move sideways during fast accelerations etc?
I have a lot many more questions but would keep it short for now.
:cheers:

WeldTutor --- your thread sure has given me a lot of Inspiration and confidence to start of my DIY Plasma.

Hi Praveen
Thanks for your interest & kind remarks. I'm pleased to hear that this thread & the table it describes, has been inspirational for you. (As well as several others) The contributions of CNC Zone members have certainly provided valuable information.

Your plasma table project should be an enjoyable learning experience for you & I look forward to seeing posts of your progress.

Test runs of my table's 4000 RPM servo motors, 30:1 speed reduction, & 3" sprocket drive system have provided linear speeds in the order of 375 inches per min. at 50% speed. This will be in the desired travel speed range required for light sheet steel. These tests were done by wiring the motors directly to the power supply, not through the Gecko drives & PC controls. Vibration does not seem to be a problem.

The X axis rails are 1-1/4" standard pipe, supported only at each end by the collars shown earlier in this thread. If flexing of these rails is a concern as might be the case for longer table lengths, the design of the table top side supports & location of the rails is such that additional intermediate supports could be added. These supports would not cause any interference with the bearing movement if positioned to the inside or below the rails.

My table is about 95% complete as it requires some alterations to the electronic controls to become fully operational.

Hi Weldtutor,
I am a computer programer by profession. But, I am a newbie to CNC world.
After I read your log, I feel excited and like to build a medium duty Plasma Table.

This is my first question in CNC world:
Q: Could I use this kit for the table:
http://www.xylotex.com/3AxSysKit.htm

Or Perhaps you can shine some light.

Thank You,

Jimmy

After I read your log, I feel excited and like to build a medium duty Plasma Table

Hi Jimmy, and welcome to CNC Zone, a great place to gain information for the project you wish to build.

The Xylotex products that you mentioned certainly have a good reputation in the CNC hobby world.

The 3 axis kit that you questioned has NEMA 23 size motors which most folks would consider rather small for your medium duty plasma table application. A more accurate answer might be given when you decide on type of construction your table will have. Things such as weight of the parts (gantry) being moved, bearing type & efficiency, mechanical drives used, motor to drive gear reduction etc. all will have an effect on operation. Xylotex could give you an opinion when you have made decisions on some of the above.

Earlier in the thread you will see a smaller plasma table pictured & with some descriptions by Trevorhinze, it's builder. His X & Y axis use the next size larger size NEMA 34 motors with a NEMA 23 on the Z axis.
WT :)

Hi Weldtutor,
Do you know where can I find the nema 34 motor and a 3 axis kit that able work togather.

Hi Weldtutor,
where can I find the nema 34 motor and a 3 axis kit
There are several sources including this one.
http://www.cncresource.com
The web site shows the smaller motors with their kit, but they offer to supply larger sizes to meet the customers needs if required. Try an email to get their suggestions for your application.

This link is to a plasma table "trainer" machine, built by CNC Zone member midiguy732. He kindly consented to use of this link so others might learn from his work.

http://frederic.midimonkey.com/cnc-gantry.html

Various interesting construction features are shown.
If you "click" on the 10th photo it will bring up a video of movement of the X & Y axis.


A second generation machine is now under construction, & still a work in progress, shown at;

http://frederic.midimonkey.com/_index.html

Click on the above link then "yard tools" in the menu, then CNC gantry II

Not even one day has passed since Weldtutor posted the links to my page(s), they got about 70 hits. Wow! To make things easier for you folks I reorganzed slightly, so that that gantry2 project is on one page. I'll probably split it up again down the road but this way there's less "work" on your part.

Old design:
http://frederic.midimonkey.com/cnc-gantry.html

New design:
http://frederic.midimonkey.com/cnc-gantry2.html

There, easier to navigate. Click and arrive!

Thanks Weldtutor for including my projects as part of this thread... I'm totally flattered!

The link below will take you to an ingenious CNC table built at very reasonable cost by Massajamesb, another 'Zone' member.

It is great example of a chain driven unit. :)

http://www.cnczone.com/forums/showthread.php?t=24187

Hi Trubleshtr
I plan to use a Thermal Dynamics Cutmaster 51 plasma cutter. There are many good machines available from the various manufacturers. I had it narrowed down to a choice of 2 manufacturers.
It would seem to be a matter of indivual preference, based on needs, after doing a search of what the market has available.
Thanks for your interest.
Weldtutor

Has anyone ever made their own plasma cutting head, complete with electronics?

Not even one day has passed since Weldtutor posted the links to my page(s), they got about 70 hits. Wow! To make things easier for you folks I reorganzed slightly, so that that gantry2 project is on one page. I'll probably split it up again down the road but this way there's less "work" on your part.

Old design:
http://frederic.midimonkey.com/cnc-gantry.html

New design:
http://frederic.midimonkey.com/cnc-gantry2.html

There, easier to navigate. Click and arrive!

Thanks Weldtutor for including my projects as part of this thread... I'm totally flattered!

hi

Midiguy , that is a nice peice of work you have posted links to , both old and new style

cheers

Has anyone ever made their own plasma cutting head, complete with electronics?
The Yahoo plasma cutting group has some information available that you may find helpful.

If you are a member there, check the FILES section for Home Brew Plasma.

You will find a schematic, a video, etc.(flame2) Be careful!

The Yahoo plasma cutting group has some information available that you may find helpful.

If you are a member there, check the FILES section for Home Brew Plasma.

You will find a schematic, a video, etc.(flame2) Be careful!

Thanks Weldtutor, I'll have to check that out. BTW do you happen to have the direct link?

Thanks Weldtutor, I'll have to check that out. BTW do you happen to have the direct link?

This is the link. It may not open unless you have signed up as a member.

http://tech.groups.yahoo.com/group/plasmacutting/files/HomeBrewPlasma/

This link will take you to another chain driven plasma table built by
Timmyb199

http://www.cnczone.com/forums/showthread.php?p=201052#post201052

Photo shows how the Y Axis carriage bearings fit to the Y Axis rails.
(Hope this answers your PM question H.C.)

The Photo Gallery has a post by Massajamesb, (thanks) of a safety sign I'll add to my plasma system.

Check it out. It might be the finishing touch for your machine.

It seems some people must watch the arc a while, before they "see the light."
.....................:withstupi

Wow, how did I miss this thread?

I got to try out a small Thermal Dynamics hand plasma unit the other day. Fantastic piece of equipment.

Anyway, Im going to have to drag myself away early this evening from my router build to read this thread. I'll resist the temptation to ask questions until I've read through in case they are already answered.

L8rs.

The Photo Gallery has a post by Massajamesb, (thanks) of a safety sign I'll add to my plasma system.

Check it out. It might be the finishing touch for your machine.

It seems some people must watch the arc a while, before they "see the light."
.....................:withstupi

Heh, I didn't want to post that up on a forum, as it might be deemed "offensive" or not "work safe". picture gallery is different.

Note: you should only bring it up if you have a sense of humor.

Pm me for a link to purchase one.

rofl! I really like that sign, and dont find it offensive at all. If your stupid enough to need the sign, then your stupid enough to need the last part! :D

now i look like a idiot.. where is that link for photo gallery?

im interested in lookin at that sign..

thanks
Dan

where is that link for photo gallery?
im interested in lookin at that sign..

At top of this page, a couple inches down, in the area highlighted in medium blue, next line under User CP, Forums, FAQ etc. click on "PHOTO GALLERY"

On the photo gallery page, about 4 inches down, in the line that will say WELCOME DanOSB, click on 7 days, if checking within the next week.

It's there with several others.

How is your machine build progressing Dan?

Phew! That was a great read. Facinating. There was certainly a lot of DIY CNC Plasma & OxyFuel tables being built in 2006! Weldtutor thats really a great job, and a very interesting thread, thanks for sharing. By coincidence, the torch I tried out the other day and mentioned in my above post was the same as yours. The Cutmaster 51. How do you find it for cnc? I was under the impression that Hypertherm had longer consumable life.
Thanks.

That was a great read. Facinating.
The Cutmaster 51. How do you find it for cnc? I was under the impression that Hypertherm had longer consumable life.
Thanks.

Glad you are enjoying this thread & the contributions others have made to it.

Many users find the Thermal Dynamics Cutmaster 50/51 plasma machine gives excellent results with CNC.

Consumable life is more related to standoff distance, pierce positioning & angle, speeds, plasma settings, dryness of air etc. than brand name on the machine.

Several manufactuers produce excellent plasma machines for CNC use with air as the plasma gas.

The claims to "longer consumable life" are often "more brand loyalty" or "marketing hype", than a careful comparison of products from other manufactures.

Thanks for the reply. Thats good to know, because its easier for me to get Thermal Dynamics than Hypertherm over here. :) :cheers:

I won't lie to you, I really really like Hypertherm. They are worth the money, but I got a heck of a deal on this Thermal Dynamics.
I will probably get another big Hypertherm for the big machine I am building, but for this small table, and what I do with it, it works fine :cheers:

Are the 'Free Plans' mentioned in the title the ones by Mike linked to in Post #11?
:cheers:

Yes, post 11 will take you to the Mike Laws plans.

When you get there there is an explanation for how to print the plans in post #15, and also an update of them in post #25.

For easy viewing & printing, Zone member 70 Cyclone has posted the plans as PDF files (Post # 43 & #44) that you might want to check first.

Although my machine does not follow Mike's plans, they provided great inspiration for me to pursue my machine build.

Photo shows sign added to plasma table.

Similar to one mentioned earlier in thread. :cool:

James,

What size of a "big machine" you building?

James,

What size of a "big machine" you building?

I am thinking along the lines of 8x 20, maybe 10x20.
I would also like to get a bunch of casters or ball transfers and make a steel sheet conveyor, so I can just roll the sheets up to and on to the table. Just a thought, though.
Whatcha got on your mind, pard?

I am thinking along the lines of 8x 20, maybe 10x20.
I would also like to get a bunch of casters or ball transfers and make a steel sheet conveyor, so I can just roll the sheets up to and on to the table. Just a thought, though.
Whatcha got on your mind, pard?

Awww nuts! And I thought I was going big with a 3mx3m table, but your building a monster. Cant wait to see that build log. :)

well, I was going to build a bridge and rail gantry machine, but if I did, I could never move it. Too much trouble, just to know I had one of the biggest homebuilt plasma tables out there.

I was just curious as to size.... It looks as if I am going with a usable size of 5' X 10' With a protected drop front rail. to allow for loading with a fork lift. I have an overhead hoist if I need to support anything longer than 10' I only have a 16' door to get anything inside my shop anyway. Most of what I burn is 3/8" & up through 1"

I have enough fork truck to handle a 4' X 8' sheet of 4" but usually buy that heavy stuffffffff (over 2") pre burned. It's rare for me to burn over 1" sometimes small parts in 1 1/4" or 1 1/2" if I happen to have a drop of that thickness. I sometimes pick up thicker drops at near scrp prices.

Only reason I am going with a 5 X 10 is: I have (1) repeat part I have been burning now for the past 3 years that it would reduce my cost per part by a couple bucks each if I could handle 5' X 10' stock. It is a 15" dia circle. On 4 X 8 I have to line them up in straight rows & columns On a 5 X 10 I can stagger them & save on cost of plate.

4" thick sheet. Man, oh man. What on earth are you burning 4" + steel for?
If you say ornamental or decorative metal I will laugh for the rest of the year.:)

4" thick sheet. Man, oh man. What on earth are you burning 4" + steel for?
If you say ornamental or decorative metal I will laugh for the rest of the year.:)

Ornamental or decorative it's not!!!! I have used in the past 24 months 500 as of yesterdays count with anothe 36 more sitting on the floor right now 16" X 20" X 4" rectangle blocks to build the part shown in the attached file. the second attachment is of some finished parts less bolt patterns that get plotted in them. It's not shown on the print but the base in the right hand view is 3.600" after facing.

...the part shown in the attached file.....the second attachment is of some finished parts less bolt patterns .....


Are you using high def plasma? This may seem like a simple question if you know the answer, but why dont I see much kerf on the cuts?

Are you using high def plasma? This may seem like a simple question if you know the answer, but why dont I see much kerf on the cuts?

Do you mean slag/dross? These parts were cut with Ox/Acet. It always amazes me how clean they really are. Very little grinding at all. The ones pictured were cut by my steel supplier. I have cut them but really hate it. Piercing is such a pain through 4". To be honest, If I do them myself I lay out the grid & pre drill with a mag base drill & 7/16" bit so I don't have to pierce. Currently I have a manual ( magnetic pattern tracer)torch so setting up on pre drilled holes isn't that much of a problem. On this thick stuff & me having to purchase 4' X 8' chunks & handle it. It's almost as cheap to have them burn it & purchase an entire sheet of larger size (much less waste). An order or full sheet usually brings me 36-40 of these blanks. Their cut charges are much less on full sheets because there is no inventory to restock. & the fact that it is a single purchase of $11,000.00 + US lets them almost cut it for free.

Attached is a pic of the axle during the welding process,these parts make up. The round bar bolted between the flanges at the top is there to help minimise warpage from welding. It is pulled out after the entire part cools.

Cool pic millman. I meant kerf, as in a slight inward taper around the inside of the cut from top to bottom, like you get cutting circles with plasma. So on one side the circle is a slightly smaller diameter than the other. I was under the impression that even with high def plasma, on a piece that thick you would have significant kerf. Maybe your supplier cuts them with abrasive water jet?

No, oxyfuel cutting generally does not have that taper that you are mentioning. Oxyfuel cutting can cut steel twice that thick with no taper. You are right, though. Even high-def plasma leaves a bevel and taper.

That's correct James, I just finished 6 of these blocks that had to be milled off around the outside edges. The very most I had to take to get a clean edge (as far as taper on the cut edge) was .040". & wasn't more than .100" out of square.

These very issues are the reason I am building a Ox/Fuel table. I need to cut some 2" material today in fact. Is there even a plasma rig out there that will do that? $ if so what would it cost?

well, for a nominal (25k for the lowest line model:eek:) fee, you can have a Hypertherm high def plasma that will still leave a bevel, though not as bad as normal plasma.
I saw one of the low line Hy-def (is there really such a thing? that sounds like an oxymoron) plasmas a year or so ago, and it was superb, and I think they burned 1/4 plate at something like 200 IPM or more. They burned 1/2 plate in no time at all, but it still had a little bevel. I think it was a 150 or 200 amp unit.

As far as cost goes, the cost of acetylene is rising, but it is hands down cheaper to go with oxy acetylene or propane, etc. than it is to go with high definition plasma, not to mention the cut edge has no bevel.

Neil, it looks from the pics that you have one huge, heavy bugger to weld there!

I should also add, in figuring the cost of high def plasma, there is also the gas needed. Most high def machines will only run off of Nitrogen and the like. That can get expensive.

I apploigize if this has been asked before, but how is the accuracy using chain? I currently have a belt driven system and I dont know if I am competely satisfied with it. The belts seem to allow a little more drift then I thought it would.

how is the accuracy using chain?

Hi Andrew, welcome back.

You would likely be satisfied, and surprised, with the results a chain driven machine can give.

In post #28 of Beetmans thread HERE (http://www.cnczone.com/forums/showthread.php?t=14743&page=2) in the main part of this forum he has a picture showing his results.

Massajamesb has recently converted his table from chain to rack & pinion & can perhaps give you a comparison. This was done more out of interest & experimentation, rather than dis-satisfaction with chain.

Both of these members have completed more cuts than I have.

millman52,

Yes there are plasma's that will cut 2". It blows sparks for miles.....when it pierces.

These larger cutting capable machines will use a 3d head. This means that they can offset the torch to say, 10, 20. 45 degress and still have dead straight cuts. Or you can have angles there for welding, saves grinding.

You can put these on lasers as well, but lasers can not cut as thick, as the more you angle the torch the thicker the cut will be.

There are oxy fuel systems that can cut 2000mm thick, yes 2meters.

Apples
Australia

Not to discount what you say, but I have just never seen a high definition plasma head be angled as you say. That is very interesting.
Learn something new all the time.

Massajamesb has recently converted his table from chain to rack & pinion & can perhaps give you a comparison. This was done more out of interest & experimentation, rather than dis-satisfaction with chain.-quote

Thank you Weldtutor, that is an excellent way of looking at it. My table has had no real problems with chains, other than user error. If I were to use the chains again, the only thing I would do differently would be to put a tensioner on the chain that connects the reduction gears. That was the cause of the only backlash I had, at least as far as I could see. Once I had that sorted out, a circle was a circle.

I would have no problems running chains again, but I wanted to try something different, so I went rack and spur gear. *Shrug* Why not? All I really gained was asthetics and higher rapid speeds. I learned something in the process.

The only downside is how much money I have tossed out the window to learn. Oh, well, it is still cheaper than buying one

Try this link to a .pdf file.


http://www.koike.com/PDF/3-d_link_bevel.pdf

Peter
Australia

Thanks!
I find it ironic that something made by Koike and that is as expensive as I expect it to be, only runs under Win98 or Nt.:)

That's correct James, I just finished 6 of these blocks that had to be milled off around the outside edges. The very most I had to take to get a clean edge (as far as taper on the cut edge) was .040". & wasn't more than .100" out of square.

These very issues are the reason I am building a Ox/Fuel table. I need to cut some 2" material today in fact. Is there even a plasma rig out there that will do that? $ if so what would it cost?

After giving it some more consideration and thinking about what you are doing, a plasma would probably not work too well for another reason. If you were to look at a circle cut with plasma, even high-def, you would notice the leadin/leadout area, looks like a little "wave" in the cut edge, pointing into the circle. The reason this is there is because if a plasma has ATHC (like most industrial units), if you were to try and cut a complete circle, you would wind up crashing the torch, because it will have no material to burn through at the point in the circle where the cut started and ends, so the torch "thinks" the material has moved, and automatically compensates, thus diving your torch into the material in an impressive and expensive impression of a shear punch.

This leadin/out area would be a bit more machine work to get perfect, as well as the fact that the bevel changes a bit depending on the direction of travel of the torch.

I am no expert, and it is merely my opinion, of course. I just don't see plasma working too well for what you are doing, Neil. Plasma is a great thing, and has a lot of uses, but I think that what you have going just can't be beat!

hi,
I wanted to build a cnc router using the jgro plans and i see that this table uses some stuff from that build. can this table be used for cnc router? It looks like it can work and i also like this design.

can this table be used for cnc router? It looks like it can work and i also like this design.
Thanks for your interest clammy23.

Sure it could be used for a CNC router with some simple changes to mount it, rather than the torch.
Other threads here at CNCzone have discussed the pros & cons of a dual purpose machine

As you point out the rails & bearings are based on the JGRO design.
For the plasma application steel is the desired construction material & certainly would be suitable for your router table build.

Massajamesb, Where did you buy your gear rack stock? What pitch did you choose?
I've been gathering parts to do a plasma table and I would like to go with a gear rack. Not sure what works the best for pitch. Did you use a belt for further reduction? Any advise or info you can provide will be greatly appreciated. Thanks,
Dick

Massajamesb, Where did you buy your gear rack stock? What pitch did you choose?
I've been gathering parts to do a plasma table and I would like to go with a gear rack. Not sure what works the best for pitch. Did you use a belt for further reduction? Any advise or info you can provide will be greatly appreciated. Thanks,
Dick

I bought it from CarrMcmaster, they get it from Std. Steel Specialty in Beaver Falls Pa, if I remember right. You can get it direct from them for a bit cheaper than Mcmaster.

I have 20 pitch, 20 degree Pressure angle. It allows for great tooth engagement,and it is quite accurate.
I got 20 tooth spur gears from Mcmaster as well.

I do have belt and pulley reduction, I have a 15 tooth pulley on the motor shaft, and a 40 tooth pulley on the spur gear shaft. Anything in this ratio range will suit you fine. I purchased my pulleys and belts from Brent Hubbard on Ebay.
http://stores.ebay.com/HUBBARD-CNC-COMPONENTS_POWER-TRANSMIION-PULLEYS-BELTS_W0QQcolZ4QQdirZ1QQfsubZ5QQftidZ2QQtZkm
He has a limited selection, but he might have what it takes to get you moving!

With the belt and pulley setup I have, one motor revolution equals about 1.18 inches of linear movement, so theoretically, one motor step should move my machine about .006. This is far more accurate than the plasma process itself, and also provides me with adequate torque.

I hope this is what you were looking for.
Sorry to hijack your thread, Weldtutor!

That's exactly what I was looking for , Thank you!
Dick

I hope this is what you were looking for.
Sorry to hijack your thread, Weldtutor!
Not a problem Massajamesb.
You were able to give Dick the information he needed, that is what is important here.

Knowledge transfer is one of the reasons CNCzone is such a great resource!:)

This might be an appropriate time to point out that the project log & discussion forums, although very closely related, are actually separate.

I certainly don't get upset about a little overlap between the main & sub-forums.

Over the last year I've had a number of requests for plans, for my CNC plasma table. I don't have a set of published plans.

If anyone needs additional pictures, measurements or specs feel free to make a request.

Perhaps someone would like to use (or develop) their CAD skills to prepare plans for free distribution to the CNC community.
I would assist with information for this, but it is not a task that I give high priority at the moment.

As mentioned in the title of the thread, there is a link to free plans. See posts #11, 15, 25, 43, & 44.

Happy Planning :)
WT

Although I really like having plans to look over, It seems I can never follow them exactly. There is always something I want to do different. Or the same materials & supplies may not be local to me for purchase.

I Want to take this opportunity to thank all those who have taken time to post pictures, plans, and share knowledge. Without these things it would have been nearly impossible for me to have started a build of my own.

Purchasing an industrial table would have been completely out of the question from the money investment standpoint. All the used machines I could dig up & afford were of the electric eye, full size plans tracer type. For me at least they gobble up way to much floor space. Then you almost have to have a drawing table as large as your torch capacity. Then where do you store all those prints drawn to full scale.

Again many thanks to everyone.

Neil

hi new to cnc anything but i am going to build a cnc plasma the big question for me is the pc computer have a way to start and stop the plasma arc or do you do this manualy

hi new to cnc anything but i am going to build a cnc plasma the big question for me is the pc computer have a way to start and stop the plasma arc or do you do this manualy

Hi, and welcome to CncZone. :wave:
You will need a special relay to do that, and your G code will send it a signal via your computer to turn it on and off. Although you can also turn it on and off manually as well as in the software.

hi new to cnc anything but i am going to build a cnc plasma
Another welcome to CNCzone, from your home province. :)

Keep reading, planning, asking questions, & the answers will be there, as you see above.

If your plasma machine has a hand torch, wiring can usually be done to leave the torch switch in tact for manual cutting, or as mentioned, to have the machine started by the CNC for automated cutting.

I wish you well with your CNC building project.

This test marking device was used to check the accuracy/repeatability of the machines X & Y axis. A dozen runs of the butterfly pattern shown in the photo were completed, in the same location.

Twist ties were used to temporarily fasten the device to the disabled Z axis.

The DXF shows the simple construction method used for the marker.

I've recently added a water tray with slats positioned so the water level can be below or above the surface of the material being cut.

The water level as I've used it, was 1/2" below the slats top edge.

Using this set-up on 16 gauge steel has given excellent cut quality & no workpiece warpage. The plasma air causes sufficient turbulence/splashing of the water under the work, to keep it cool.

DXF shows construction details.
Photos are of slat side & centre supports as well as finished tray with slats.

A 1 1/2" pipe & brass gate valve was provided for drainage.

The curvature of 1" in the slats prevents them from 'rocking.'

Glad to see it warmed up so you could go back to work. Great idea with the water.
mike

Looks excellent. How about some more pictures of the water table construction?

How about some more pictures of the water table construction?

If there are specific shots needed let me know & I'll photograph if possible & post them.

I tried to show most construction details in the DXF drawing posted above.

The side supports for the slats are 2 pieces of angle iron on each side. These are 'nested' together & welded, resulting in a channel formation. A chop saw was used to cut the openings for the slats to rest in.

Depth of the water tray is 4".

Position of the slats is such, that the water level could be 1/2" above the top edge of the slats if desired.

Well, what you are describing to me makes sense, and I did open the DXF, but I know some vistors can't/don't have a way to open dxf files.

How about a question, how did you make it water tight when you welded it all together? I am sure some would love to know that, since that is difficult to do with mig welding.

Well, what you are describing to me makes sense, and I did open the DXF,
How about a question, how did you make it water tight when you welded it all together?


The attached photo is a screenshot of the previously posted DXF. This will show the info for those who cannot open the CAD file otherwise.
As for a water tight weld, I believe you previously mentioned in another post that you had some chewing gum available! (nuts)
Not having the gum, I had to resort to careful fitting & tack welding, followed by the main weld. (MIG)
Perhaps it was luck, good fortune, position of the stars, or maybe even a few years of experience, but the 12 gauge tray is water tight.

"Cold lapping" or lack of fusion can be a problem with the GMAW (MIG) process.
Gun to work angle, wire drive speed, voltage setting, travel direction & speed, gas coverage, & electrical stickout (contact tip to work surface distance) are all important parameters.

Excessive "stickout" is the cause of many of the MIG weld failures. This results in a situation that does not generate sufficient amperage to fuse an otherwise "good looking" weld to the base metal.

The attached photo is a screenshot of the previously posted DXF. This will show the info for those who cannot open the CAD file otherwise.
As for a water tight weld, I believe you previously mentioned in another post that you had some chewing gum available! (nuts)
Not having the gum, I had to resort to careful fitting & tack welding, followed by the main weld. (MIG)
Perhaps it was luck, good fortune, position of the stars, or maybe even a few years of experience, but the 12 gauge tray is water tight.

"Cold lapping" or lack of fusion can be a problem with the GMAW (MIG) process.
Gun to work angle, wire drive speed, voltage setting, travel direction & speed, gas coverage, & electrical stickout (contact tip to work surface distance) are all important parameters.

Excessive "stickout" is the cause of many of the MIG weld failures. This results in a situation that does not generate sufficient amperage to fuse an otherwise "good looking" weld to the base metal.


Thanks, Weldtutor. As far as the welding goes, I should have said, "GMAW starts cold, making it hard to get a air or water tight seal. Most anything that requires air or fluid like that, I GTAW. I was just curious if you had a special method to share.

And no, you can't have my chewing gum. By now, it is a flavor all its' own, and has excellent sealing properties :D

"GMAW starts cold, making it hard to get a air or water tight seal. I was just curious if you had a special method to share.

Quick answer: Short stickout.

All the points listed above are important for a quality GMAW deposit.

Some operators hold an electrical stickout distance that is too great when initiating the arc, or an improper contact tip to work angle.

The distance from where the electrode wire leaves the contact tip, to where it touches the work (combined with wire drive speed) determines the amperage generated by the constant voltage power source used for this process. Variations in the tip to work angle, will therefore change the amperage as well.

If your power source has meters on it, observe the amperage reading when using a 3/8" stickout compared to the reading with a 3/4" stickout. If you don't have meters, you might compare the result with a 3" stickout where the wire gets hot & eventually melts, but less heat (amperage) is resultant.

Quick answer: Short stickout.

All the points listed above are important for a quality GMAW deposit.

Some operators hold an electrical stickout distance that is too great when initiating the arc, or an improper contact tip to work angle.

The distance from where the electrode wire leaves the contact tip, to where it touches the work (combined with wire drive speed) determines the amperage generated by the constant voltage power source used for this process. Variations in the tip to work angle, will therefore change the amperage as well.

If your power source has meters on it, observe the amperage reading when using a 3/8" stickout compared to the reading with a 3/4" stickout. If you don't have meters, you might compare the result with a 3" stickout where the wire gets hot & eventually melts, but less heat (amperage) is resultant.

Another thing I find helps with starts is cut or break your wire back to eleminate a burned portion or small ball on the end of the wire. I generally don't have a problem getting water or air tight joints with MIG either. Experience does play a role in it though I also have been welding for years.
I will also cut wire feed back ever so slightly for welding a "must be sealed" joint.

Another thing I find helps with starts is cut or break your wire back to eleminate a burned portion or small ball on the end of the wire.
I will also cut wire feed back ever so slightly for welding a "must be sealed" joint.
You raise another excellent point Millman!

Sometimes we have to resort to our whole "bag of tricks" for applications where the utmost of weld quality is required.:devious:

It seems That cutting the feed a bit gives slightly better control of your puddle & gives a bit flatter bead. I use 100% CO2 which spatters a little more but it also allows for a little greater penitration.

I don't know what others have found but I have never been able to use the "gas not needed" flux core wires with success to my satisfaction. I much prefer the puddle control that is given by a dual shield wire. Then switch to a hard wire when work gets into & thinner than 11 ga.

This is one of those subjects that varies so much because of the equipment you have at your disposal. I have had the opportunity to test use many of the smaller home shop machines out there today. Many of them seem to be pretty good welders for the price.

If I have a job I really need my welds looking the best possible. I still revert back to 1960's technology "electric motor driven generator" Hobart mig machine that doesn't have a "PC" board in it anywhere & probably weighs near 800 #. It's really hard to beat the arc characteristics of pure DC current that is not converted from AC transformers. It's just way to expensive to produce that type of welding machine today.

hi every body picked up an allen-bradley slc 150 programmable controller and i was just wanting to know if this could be used to drive the steppers on a plasma table any help would be great. if some one has a wiring plans for this controller please post it

The photos are of cuts made with my CNC plasma table since the recent addition of the water tray.

All material shown is 16ga. steel.
Settings used;
120 inches per min.
70 PSI air
30 amps

The dragon fly head & wings show excellent "as cut" finish & the coyote head & feet have nice sharp detail.

I am very pleased with accuracy & quality of the parts produced by the chain drive system, Thermal Dynamics Cutmaster 51 plasma machine, and integrated computer/controller from CNCzone member Mlaws1172.

Looks like you are having fun! Great looking cuts
mike

The photos are of cuts made with my CNC plasma table since the recent addition of the water tray.

Nice looking cuts.. So lets hear more about the water table addition. details? More pictures?

DeviousMW

The water tray is of 12 Ga. steel construction, coated inside with a high zinc content finish.
Depth is 4"
Slats are 1/8" X 2"
Supports for slats are at each end & centre.
Top edge of slats is 1/2" below top of water tray.

See posts # 161, 164 & 166 above for additional pictures & information.(wedge)

Photos attached here show an overall view as well as the hangers for the water tray & also the hangers for slat end support devices which are inside the water tray, at each of the 4 corners.

The water tray is of 12 Ga. steel construction, coated inside with a high zinc content finish.

Why the high zinc content finish? resist rustingI assume? What paint or finish did you use? Where did you get it from?

Thanks,
DeviousMW

Yes, the coating is to prevent rusting of the water tray.

I used a brush on material, no name brand, from a local chemical company.

Rustoleum also has a somewhat similar product available in a spray can.

Thank you for sharing this. What type of a relay are you using to turn the torch head on/off?

Thanks,
Drafterman

What type of a relay are you using to turn the torch head on/off?


The relay is a Millionspot H500 see HERE (http://www.millionspot.com/pframe.html)
It is controled by the "spindle" output in the software & sends a signal to the start terminals on the plasma machine circuit board.

Some breakout boards have a suitable relay attached, or a relay board as an accessory.

These show some of my recent fun cuts.:)

Pug file was a download.
The others & those back in post #173 were drawn in my CAD program & saved as DXF files.

Same 16 ga.steel & settings as in post #173

Sailfish is 34" long, jumping salmon is 16" long.

x

You have sparked my interest and I am planning a similar build. On the floating torch mount plate that rests on the work surface via the transfer balls...what happens when one or more of the transfer balls rolls onto a portion of plate that has already been cut and/or has already dropped out?

what happens when one or more of the transfer balls rolls onto a portion of plate that has already been cut?

One ball off the work has no effect, 2 show a very slight move of the torch mount plate with no apparent variation in the cut.
Careful adujustment of the compression spring pressure on the 4 plate mounting bolts seems to be a key to smooth movement.

I wish you well with your project & look forward to posts of the results.

So I take it the ball transfer THC is working quite well for you!
I would like it if you could get a video up of it cutting an intricate part, so we could see how well it works.

Still lookin' good, Weldtutor!

So I take it the ball transfer THC is working quite well for you!


Yes, I have to say I am very surprised with the high quality of the results it produces for me.
Being somewhat skeptical myself, & hearing stories about tip-ups, & jamming etc, I was considering purchase of a digital THC even days before I made the first cuts with the machine.

Various threads seem to show that not all electronic THC users are happy with the results they get, nor the set-up problems they must endure.

I will say that if a THC fell off a truck I'd grab it & install it. :)

To purchase one with to-day's Canadian dollars, pay border brokerage, add the shipping, maybe some import duty, depending on whether the customs officer is having a good day or not, federal & provincial taxes, all would total in the $1000 Cdn range. (Not in my cash box to-day.)

Although I did try to upload a small video last week, but alas, it was too large for the 'Zone' restrictions.

I have to find a video/photo host that I am satisfied will not make me sign my first born or my life away with conditions, or if anyone's interested just fly north to my igloo & I'll demonstrate that it really does work.

Chains, sprockets, transfer bearings, skate bearings, steel tube from my scrap heap, used water pipe from my well were all incorporated into the project, as was a lot of (help) & knowledge gleaned from other members here at CNCzone.

[QUOTE=Weldtutor;

for if anyone's interested just fly north to my igloo & I'll demonstrate that it really does work.


Weldtutor, where abouts in the great white north are you from. I just might take you up on your offer in the summer when I fly back to visit my parents?

Grindergary

Weldtutor, where abouts in the great white north are you.

My Igloo is the one with the hole melted in the roof & the steam rising out of it.
I'll wave to you :wave: when I see the dog sled taxi approaching.

I was using my CNC plasma cutter to create an address sign to make it easy for you to find me.
That 30,000 degrees (flame2) sure did a lot of damage to the roof.

bruce
i like all your cuts - we need to do some pattern file swapping
mike

i like all your cuts


Thanks Mike,

I really like the controls you put together for me.:banana:

Just noticed the new pictures you posted.

If you have always had trouble getting around to it, this post might be for you.

I might be convinced to swap my DXF file for one of yours for plasma art, if you PM me.:wave:

I, myself have always had trouble finding time to get a round tuit,
it appears that you are out to save others like me some time and trouble :)

Stupid Question!....Whats a TUIT?

"Getting around to it" = getting a round tuit.
it is a play on words. It is a habit of some of ours, when we need to do something that we have been putting off, to say, " I need to get around to it". Meaning, I need to get that done, but it is not at the top of my priority list.
Now that you understand, you too can have a round tuit:D

"Getting around to it" = getting a round tuit.

Now that you understand, you too can have a round tuit

Good explanation.

Say it out loud, get a round tuit! :confused:

The attached are some recent projects with cuts made by my CNC plasma machine.

Spiral is 4" O.D. X 1/2" wide, Leaf 2" X 2"
Mask of comedy 14" X 8"
Cat 10" long
Fish 10" long, but I catch much larger ones in the lake! :cool:

Hi Weldtutor,
It's wonderful for your pictures. I am building plasma machine. Could you please help me for electronic wiring? I have some questions

What pin of DB-25 parallel port can control M03 and M05 command? please advise. :confused:


Regards,
Mongkol

Mongkol, this LINK (http://www.campbelldesigns.com/breakout-board-mach2-3-files.php)will take you to a site with several PDF files that should help.

Hi Weldtutor,
Thank you very much for your advice.

Regards,
Mongkol

You are quite welcome Mongkol.:)

Don't forget to post some information about your machine project, & maybe some pictures to help others as you progress.

Very Nice thread. Thanks for all the information.

Very Nice thread.

Hi JHCHOPPERS, & welcome to CNC Zone! :wave:
This is a great place to get information & share ideas.

Many members have contributed to this & the other threads.
Thanks for the kind words.
WT

love your design--how are you driving the x y axis do you have pics for that part

love your design--how are you driving the x y axis

Hi Pyaden,
Thanks for your interest.
Glad you like the design. :)
The machine is working quite well for me.

The first photo is a close-up of the X drive motor & gearbox. The output shaft from the 'box transmits power to a cross shaft to drive both sides of the X axis.

Second photo shows one X sprocket in the foreground, with the opposite side sprocket in background behind the 'box.

Third is a close -up of the Y drive motor & gearbox mounted on the gantry.

Fourth is the drive side of gantry (y Axis)

Fifth is torch mount side of gantry.

Viewing of these, as well as the pictures posted earlier in the thread should give an idea of the location of the drives & their operation.
If you need more information feel free to ask.

This may sound dumb to most of you guys...but how does the torch start and stop? Does Mach3 control that?

Vince

how does the torch start and stop? Does Mach3 control that?
Vince
Mach3 is the control program, which runs the CNC machine language (G & M) codes.

An M code number can be located in the program, where needed, to send a signal that activates a relay on or off, which in turn is connected to the plasma torch switch circuit to start or stop the plasma unit.

The machine codes then are telling the torch where to go, how fast, & what to do when it gets there.

Keep asking questions, there is lots of help available from the members here at CNC Zone.

Thanks Weldtutor,
You hold true to your name.
I plan to buy a controller from candcnc.com I trust they should have everything I need to get my machine running...I hope.

Thanks again
Vince

The plazpaks come with everything you need (including MACH3 control software) and custom profiles that load and setup all of the pins and stuff for not only the torch on/off relay but three more auxillary relays (included) to optional control fans, lights, misters, etc.
tomCAUDLE
www.CandCNC.com
BOB's
Digital THCs
DXFTool Software
Complete Electronic Packages
Stepper & Servo Systems
Hand Controllers

Weldtutor, Mlaws1172 and others:

I recently did a new product announcement for a line of modular plug-together cards that will interface with all of our BOB's and the MP1000 digital THC line of interface controls. For the few hours it stayed up before the Chinese Oil Recycle products and cheap dial calipers bounced me, it got quite a few hits.

Called the "EZPlug Series" It makes wiring a complete 3 or 4 axis control cabinet about a 30 minute job (with time for a liquid refreshment break). I also gave the website a face lift to try and help un-confuse the customers. We sell so many products now (and it's fixing to get worse) that even I was getting lost.:eek:

See if the new site makes sense and it's clear that you can buy it complete or build it modular.(?)

TOM C

See if the new site makes sense and it's clear that you can buy it complete or build it modular.(?)

TOM C

Nice job on the re-work of the site Tom. :)

It is clear to me that a complete build, or modular components are available for purchase.

The modular map with graphical layout (http://www.candcnc.com/ProductLine_MP1000-web.htm), should be especially helpful to understand the function & connection of the various components for a CNC plasma set-up.

Again in contact, I already started my plasma table, but I have one question, somwhere in the forum I see something about conecting two stepmotors at the same drive( for the gantry motion) is it possible or do I have to get another drive?
Thanks
Luis

You need another drive.

Just make the extra motor/drive a slave in Mach3, etc...


.

-

The Bowtie, Oval, & Ram are slightly modified logos I cut for my automobile trivia collection.

As mentioned earlier in the thread a floating torch mount is used, along with chain drives.

The machine continues to provide high quality cuts! :)

The football will be for my fantasy league trophy.

Flaming sign is 24" X 12". (flame2)

Both items are cut from 16 ga. steel sheet.

Nice cuts!!
mike

Weldtutor,
Very nice table you have there. I am looking at driving using a similar setup with chains. I just can't justify the cost of screws or rack for a large table. Are you using servo motors or stepper's? What size (oz in) are they? I'm wondering if the loses in the gear reduction and weight of the chain, etc might suggest larger than the normally recommend ~600 oz ins.

Also what drivers are you running?

Thanks in advance! Your pragmatic approach to design and build is exactly what I am planning to do.

Thomas

Thomas, standard steel, 75" of gear rack 20 pitch X $ 24, that is not too expensive, and you can have much accuracy than with chains .

Weldtutor,
Very nice table you have there. Are you using servo motors or stepper's? What size (oz in) are they?
Also what drivers are you running?

Thanks in advance! Your pragmatic approach to design and build is exactly what I am planning to do.


Thanks for the kind words Thomas. :) I am very pleased with the output my chain driven table produces.

The 3 axis motors are Electro-Craft brush type servo motors.

Max peak torque 180 oz-in (1,27 Nm) at 12 A.

GeckoDrive G320 servo amps are being used.

I wish you well with the build you are planning.

Weldtutor,
Thanks for the info. I'll be starting on my table build tomorrow. Cutting area will be 74" x 100" and the table will be very heavy as that is the material I have available. I'll be making buckets and attachments for construction equipment so high accuracy is not important to me. I've got a plasma but I think it will be a flame cut setup instead. I need an additional axis to make beveled cuts on heavy plate steel (1/2"). I can setup that bevel cut manually and then I hope to automate the function once the table is stable and running good.

Things like linear rail, rack gearing, etc... would kill my budget and aren't needed for my purposes. I don't need speed either.... don't really care how long it takes to cut the pieces.... even 5 - 10 IPM would be fine.

I'm thinking that the cnc stepper packages from hobbycnc.com would work fine. Also planning to use lots of 1/2 R8 bearings from ebay on sch 40 pipe for the slides. It kinda reminds me of a steel roller coaster system. :-)

At the moment I am leaning towards timing belt for the drives as there is a seller on ebay and the system seems reasonably priced. I've setup automatic slide chain drive gate openers so the chain doesn't scare me but it can be a pain to work with sometimes.

The gantry will be mostly aluminum as we have the materials and TIG capabilities to work with it.

If all goes well I will be building an even larger table to do full size sheets of plate steel up to 20ft in length.

I'll setup a log posting as I get underway.

Thomas

Hi All

hi from downunder, at work we recently got a plasmacam cutting table, and as a result of using are now having to build one for myself at home!!, there is guy at work who has built mills etc using gecko drives and is guiding me along.

I am half way thru desiging the machine on solidworks, i am trying to make the machine light enough to fold up against a wall when not in use. the heaviest plate used is 3mm. I am using a single drive for X axis with a shaft thru the center of the y axis to drive chains at both ends, the y axis will be a chain drive as well, as for the Z axis yet to get that far!!! the chain will be fixed both ends and will go around idlers to get to the drive sprocket. there should be minimal backlash in this setup. for bearing i am looking at Igus bushes plastic oil impreganated, the main x axis will be 50mm x 50mm RHS with bearings tracking along it, with spring loaded rollers to keep it "tight"

One query i have is regard the THC, i have yet to work out what mach3 is looking for, i see there are two inputs for lift torch and lower torch, if either have no signal i assume then the hieght is held by mach 3, the plasmacam system works on tip voltage, you preset the voltage and the hieght automatically adjusts, being a newbie here, i assume if a PIC controller can be setup with a voltage compare function, then it can output the up or down signals, i struggle with a 1k investment for a $10 chip,
so if anyone can elighten me on the thc process please let me know

Cheers

Pedro

Hi All



One query i have is regard the THC, i have yet to work out what mach3 is looking for, i see there are two inputs for lift torch and lower torch, if either have no signal i assume then the hieght is held by mach 3, the plasmacam system works on tip voltage, you preset the voltage and the hieght automatically adjusts, being a newbie here, i assume if a PIC controller can be setup with a voltage compare function, then it can output the up or down signals, i struggle with a 1k investment for a $10 chip,
so if anyone can elighten me on the thc process please let me know

Cheers

Pedro

Yep, you figured it all out. A $10.00 chip (actually you can do it with a $2.00 chip) and bingo you have a $990.00 big old chunk of profit!:banana:

Better buy a few spares. You'll burn up a lot of stuff until you figure out what the magic formula is for proper noise suppression, loop response rate, voltage spikes, isolation, bad grounding, etc. Might want to have a spare MB for the PC as well.

Looking at the raw cost of parts in a system is only one factor. Software costs pennies to produce/ship. Why would I give more than $4.95 for ANY software program (including Solidworks) considering a CD costs less than 50 cents?

TOM CAUDLE
Running Dog of Capitalism
www.CandCNC.com

after reading this post all 13 pages i think it was you have inspired me to start work on my plasma table. i love the KISS concept of the build and how well it worked out.

i know i can build everything needed my self. but im still iffy on the whole electrontics part of it and how they effect the speed. not sure how the gear ratios from the motor to the chain. i take it that the electronics must control the motor dirves for the gear ratios needed to cut. i might not make any sense

but maybe some one can guid me a lil more in this or direct me to a post that can explain this to me better.


GREAT build i cant wait to get started on my own.

after reading this post all 13 pages i think it was you have inspired me to start work on my plasma table. i love the KISS concept of the build and how well it worked out.

i know i can build everything needed my self. but im still iffy on the whole electrontics part of it and how they effect the speed. not sure how the gear ratios from the motor to the chain. i take it that the electronics must control the motor dirves for the gear ratios needed to cut. i might not make any sense

but maybe some one can guid me a lil more in this or direct me to a post that can explain this to me better.


GREAT build i cant wait to get started on my own.

I was in the same situation as you with the electronics end of building a table.

I decided to go with Torchhead's system. www.CandCNC.com because it is the most Plug & play ready system I could find on the market. Tom asls had good customer support after the sale.

I'm not saying there aren't other good systems out there. Just that CNC's kits are put together in an exceptionally neat manner. & seem to be built from high quality parts. About the only wiring there is to do is limit & home switches to the table I/O card. They also send a set up CD with the kit that takes care of setting lots of items in Mach

No matter what electronics you decide to use there is still quite a learning curve to getting Mach configured for your table. You'll also have to learn enough about a CAM software to be able to convert a drawing into usable code for mach.

Good luck. You can depend on getting lots of help here no matter what you decide.

you have inspired me to start work on my plasma table. i love the KISS concept of the build and how well it worked out.

GREAT build i cant wait to get started on my own.

Welcome to CNC zone! :wave:

Glad this project has provided some inspiration for you.
As you see, many members have contributed to it.

Millman's suggestions above are good advice.

The electronics can seem to be very challenging, but reading, studying, & asking questions will provide you with a lot of helpful information.

Operation wise, you need to:
-make a drawing, (CAD)
-convert drawing to G-code (CAM)
-load the code into control program (Mach or other) that is used.

The control program tells the mechanical parts where to go, at what speed, & what to do.

I wish you well with your project.

Photo shows 2 miniature steel items for projects I am working on.
These were both cut with the chain driven machine in this thread.:)


Maple leaf has a polished surface that is reflecting red spectrum colour.
Upper left quadrant is as well defined as the right side, with nice sharp leaf points.

Violin :violin:has a wire brushed finish, also with very crisp edges.

I am impressed with the miniature cuts you made with your machine. The pics you posted tell me a lot of the resolution attainable w/ a plasma. The detail is quite good for a piece that size.

does the watertable truly prevent all fumes, also what different water heights are best for cutting?
benergy

Watertable does NOT prevent all fumes. Depending on the proximity to the back of the material it can be 95% (touching the material) to about 50% (greater than 2" below). The fumes are mostly vaporized metal and are lighter than air so float around the shop an coat everything with an abrasive and conductive film. It's rough on any equipment and death to any exposed electronics. Any form of dust extraction helps but the best method of you have to keep the other equipment in you shop clean is to have the plasma in a separate cut room or under a protective tent with filtered dust extraction. Localized dust extraction (like for router cutting at the cut spot) will not work since the smoke and fumes come out all under the material. A good downdraft system (min 30 CFM per sq ft) into either a multi-stage filter system of exhausted outside combined with a water tray will control most of the problem.

In the South where it stays warm most of the year we just have the table next to large door and blow the smoke outside while using a water tray to catch the sparks and hot fallout.

does the watertable truly prevent all fumes, also what different water heights are best?


Most of the cutting done with my CNC plasma is with the water touching the underside of the workpiece, or to about 1/2" below the work.

As stated in the reply above, from Torchhead, some of the fumes (metallic dust) are not collected in the water tray.
A small amount of "sparks" (dust) tend to bounce off the top surface of the material being severed.

Hi All,
Water table or No water table. How to differ? I only know watar table can safe dust and flame as cutting.
The quality of material edge and accuracy after cut. How to differ?


Thank you
Mongkol

Hi, I am a newbie looking for information on building a 5X12 Downdraft Plasma Table. Anyone know where I can get plans or information on building a downdraft tables?

Kind regards Noel

where I can get plans or information on building a downdraft tables?

Back on page 1, post #11 you will find a link to the plans that member Mlaws1172 has contributed for downloading.

The size could be varied to meet your requirements.

Thanks, I'm more interested in what design type gives the best fume exstraction results?

Hi Weldtutor,

Firstly, I want to congratulate you on a super machine. It has inspired me to take the plunge. I plan to borrow most if not all of your ideas....

Can you tell me what diameter pipe/tube/round bar are you using as rails? (im sorry if you have mentioned this already.)

On another point, I already have an oxy-propane cutting setup. Is it easy to set up a CNC Gas cutting machine. Sometimes when I am cutting manually, I have to stop midway through a cut to get heat back into the plate. I know its either my flame setup or my speed is wrong. Would this problem be evident in a cnc machine. I have never used a plasma cutter but I'm assuming that it will cut consistently on the pull of a trigger. I plan on making my machine for the gas, wood router and if the gas doesnt work out maybe buy a plasma.

Regards,
Ronan

I plan to borrow most if not all of your ideas....

Can you tell me what diameter pipe/tube/round bar are you using as rails?

Is it easy to set up a CNC Gas cutting machine.


Hi Ronan,

Thanks for the kind words. A lot of help & ideas came from members here at CNC Zone. :)

National standard, schedule 40, wall thickness pipe was used for each axis.
X axis is 1 1/4" nominal size.
Y axis 1"
Z axis 1/2"

CNC gas cutting machines have been built by several members. Accurate Mike, & Millman52 come to mind, & there are others as well who's work might be worth studying to make things easier.

With the correct size tip, pressure settings, flame adjustment, preheat & travel speed a continuous cut should be possible manually or automated. These are the variables that are changed to match the different material thicknesses being severed.

Gas solenoid valves would normally be used to control the fuel gas, preheat oxygen & cutting oxygen flow.

For plasma arc cutting a relay switch is connected to the start circuit of the plasma machine so the torch trigger need not be activated manually.

When properly installed & coded the CNC machine controller will send signals to the solenoids or the relay to do the neccesary jobs.

I wish you well with your project.

rgillard,
As weldtutor stated continuous cut should be obtainable. I use ox/acet The major differance in propane & acet. is Acet is hotter & taked much less preheat time. Not sure but cut speed in IPM should be very near the same.

Most likely your having to stop to re heat is due to either a surface contamination, heavy mill scale or more likely the shakey movement of hand cutting.

You can not use an automated torch height controller that will automatically adjust to warpage of a sheet of metal with ox/fuel. You have to manually jog for that.

Thanks lads for your advise. I am going to firstly try to build an oxy-propane CNC. The only thing I need to buy is an automatic cutting torch that has a relay/solenoid to turn on the cutting oxygen. That right? Anyone know of any good sites that I could get one of these.This will mean that I can build the table for relatively little cost. if that doesnt work out too well Ill buy a plasma but they are very expensive on this little island. Thanks for the inspiration men.

This link (http://www.cnczone.com/forums/showthread.php?t=6923) shows a manual cutting attachment used for CNC cutting with an air cylinder to activate the cutting lever.

More often, a 3 hose machine type cutting torch (not an automatic) is used.

Solenoid gas valves are added to the supply hoses, & relay switches are in the CNC controls to activate the solenoid valves.

In this project log (http://www.cnczone.com/forums/showthread.php?t=31133&page=7)by millman52 see post #74 for pictures of some solenoid valve & hose arrangements.

Any reliable welding supplier should have "solenoid gas valves" & a "machine cutting torch" or a web search for either will show results.

Hi,
does anyone in this thread know if migwelding can be done in a cnc fashion?I have a product that needs to be duplicated over and over again with a great deal of accuracy. Any suggestions? Artinvegas...

anyone in this thread know if migwelding can be done in a cnc fashion?Any suggestions?

The quick answer is yes.

Certainly there are limitations & specific requirements depending on the actual welds.:confused:

Most CNC plasma cutting machines are 3 axis & could be adapted to MIG weld a Tee or other joint that is straight & in one position.
Joints that are circular, curved, or more than one position require manipulation of the weld gun that need at least 1 additional axis.
The fourth axis control might be used to control a welding positioner rather than for gun rotation.

A lot depends upon the weld geometry & position.

MIG uses the same basic process as plasma: Constant current arc. That means you can measure the arc gap in volts. The range is dramatically lower than (10- 30VDC) plasma so the electronics need to be scaled to that range. I suspect the voltage sensitivity would need to be greater than the + - 1V we use for palsma.

I have never done it myself but the automatic welding machines use that method. The challenge would probably be controlling the wire feed based on the feedrate and getting the arc started properly (and sensed). Because the demand is so low for a MIT or TIG CNC welder we have not taken it past the theory stage. We though about offering it as a product but the R& D to get a working unit is greater than any projected sales we might achieve.

Tom Caudle
www.CandCNC.com

Torchhead-

I use Motoman 6 axis MIG welding robots daily. We usually adjust the volts by 1 volt at a time, and adjust the amps between 5-10 amps at a time. For the most part we use a ratio to set the conditions up. 20 volts ---200 amps 21 volts 210 amps 24 volts 240 amps.

Hope this is helpfull.


Steve

Bruce
This sounds like the project for you.:)

Mike

Hi Mike,
I did go the other way around about 20 years ago when I set up a 5 axis Fanuc welding robot, to cut with a Max 40 plasma machine.

Yes I have thought of adapting my CNC plasma machine to do some GMAW (MIG) but I don't have an application for it.

The welding gun would easily fit to a plate similar to the plasma torch mount.

Being that a constant voltage power source is used for most "MIG" welding that parameter is easily preset on the welding machine.

Amperage is a function of wire drive speed (again preset) as well as electrical "stickout" distance (contact tip to work distance). The Z axis would easily control "stickout" & thus amperage in conjuntion with the wire drive speed.

For straight welds, one position, the X & Y controls should work well.

Seems as if it would be rather straight forward for repetitious welds with simple geometry.

Hmmm.........:wee:

Ya, but the fun factor and who know more about welding than the Welding God himself.

Mike

Yup, this CNC stuff sure is fun.

Sounds as if perhaps you are throwing out a challenge........:stickpoke?????

Let's see........ :devious: a "mini tin" CNC machine............a MIG gun attached in place of the engraver/router............

Sure, I could make that weld! :banana:

Just so happens one already had your name on it. I just couldnt stand thinking about you laying around all winter
mike

also already thinking about how to the fourth axis

Just so happens one already had your name on it.

Hmmm, now I'm getting interested.:confused:

Rather than laying around, I chip ice out of the water tray for the plasma table. Maybe next year I'll use anti-freeze or invest in a shop heater. Then there is always global warming that might help the problem.(flame2)

A fourth axis could possibly be a rotating/tilting welding positioner with limit switches at the desired stop locations, or perhaps tilting the welding gun mount depending on the weld joint configuration.

Bruce
I though if you are interested I would get you a knocked down version to play with

mike

I'll PM you Mike.

This is in answer to a question in another thread regarding software used for drawings for plasma cuts.

Progecad LT 2006 was used for the drawings for these items pictured in this thread.:banana:

Pictures are in above posts #173, 181 (2 fish & sunface) #196, 215, & 226 etc.

how is the welding going?

I have been tempted to post many times in the last few months about building a diy plasma table. Most of my questions have been asked and/or answered by others on one or more forums.
I am going to build a table for my plasma. I have no experience with the software for cnc, cad, cam or the electronics involved. I am not a machinist or metal fabricator. I am a full time family guy who thinks welding is fun and wants to do some artistic stuff with my fathersday present (td cm-82) -I'm a veterinarian on the side.
Like many first timers I am a bit overwelmed by the technology of this field. It seems most posters are in this as a carreer, and many questions are answered in ways that further confuse the rookie questioner- sometimes even to the point of being condescending and rude. I make my first post here because I feel guys like weldtuter and mlaws have had imense patience with guys like me.
Can an intelegent guy who can build a sturdy table with good mechanics run the operating system(such as mach) without a degree in mechanical engineering or a decade or two of machining experience? What would you suggest as a study guide for the cnc rookie? Is there a "cnc for dummies" book?
I thought I had found the golden egg when Mike Law's table plans were downloaded and printed. Then I drove down to his place and met him and his table in person. That's when he mentioned some of the changes he would make on his table- belt drive system, thc (yes or no?). I'm the kind of guy who you give a plan to, and in a reasonable amount of time the end product is produced- exactly like the plan. Mike is a pioneer in the field who, without a dought, never stops thinking how he can improve it. In my attempt to "kiss" this table plan I came across a linear motion system at cncrouterparts that seems very simple and affordable. What's your opinion? It would be very easy to substitute some 1/4 inch plate or angle iron for the round rail/bearings in Mike's plan- at least on the x and y. Do you think this would be a good idea or a downgrade?(durability, lubrication issues?)
My plan is to build the table and gantry now and figure out the drive system on the way. Many thanks to you, Mike and everyone else who contributed to this valuable knowledge base. Sorry for being so long-winded! Don L.

how is the welding going?

I haven't taken up the challenge yet, but I haven't given up!:rolleyes:

I have been tempted to post many times I am going to build a table for my plasma. I have no experience with the software for cnc, cad, cam or the electronics involved. I am not a machinist or metal fabricator.
Can an intelegent guy who can build a sturdy table with good mechanics run the operating system
What would you suggest as a study guide for the cnc rookie?
My plan is to build the table and gantry now and figure out the drive system on the way.

Hi Big-D & welcome to CNC Zone.:wave:

Good to see your first post which is a great way to get information in the various forums. The majority of the members will try to be helpful.

Your Thermal Dynamics plasma cutter should do an excellent job on the CNC plasma table you are going to build. (Yes, You can do it!)

Considering alternatives to Mike's plans (which greatly inspired me) shows you already have some sound understanding of how the table will function.
Simple & affordable modifications are always important & your suggestion would be worthy of incorporation into a table, as would others.
There are many bearing systems & mechanical drive methods that will do a fine job for a plasma table.

Reading & posting questions in the CNC Zone forums is the best study guide in my opinion, & it is not a dumb question if you do not know the answer!
The software for drawing (CAD); file conversion (CAM); & machine control (MACH or others) all have good support in the forums. They can be challenging to learn, but You can do it! Electronics packages are available to help simplify your build which also have supplier support.

Welding is also fun for me, and so is CNC plasma arc cutting. :banana:
WT

Big-D take a look at my build. You can really simplify what I have done here: http://www.cnczone.com/forums/showthread.php?t=31133 Use your angle idea as opposed to the replacable round rail I used. The opposite side I made to float on the flat bar therefore doesn't have to be perfectly parallel with the round rail. Mine is very straight but would tolerate being out as much as 3/8" along the side with the flat bar. The "round rail" side is where all my tracking precision is built in. The Flat bar need not be bolted in like I have done. tack welding would be fast & work fine. Just makes worn rails a bit harder to replace.

I have had my table cutting parts for a few weeks now. I am amazed at how crisp & smooth my cut edges are. By far superior to what I have been purchasing from my steel supplier. I am literally burning some holes I had to drill because my supplier couldn't hold tight enough tolerances.

I am using Ox/Fuel so I was afraid heat build up in the Y axis rail might make it grow enough to create unwanted friction if it were bound up down both sides with linear rails.

Once the stepper motors or jack shaft is installed on the rack gears or what ever drive method, notched belt, sprocket chain, etc. you employ your gantry becomes very rigid & will track as straigh as you make the 1st. side of the table.

In my attempt to "kiss" this table plan I came across a linear motion system at cncrouterparts that seems very simple and affordable. What's your opinion? It would be very easy to substitute some 1/4 inch plate or angle iron for the round rail/bearings in Mike's plan- at least on the x and y. Do you think this would be a good idea or a downgrade?(durability, lubrication issues?)
My plan is to build the table and gantry now and figure out the drive system on the way. Many thanks to you, Mike and everyone else who contributed to this valuable knowledge base. Sorry for being so long-winded! Don L.

The carrage at routerparts looks to be a easily repairable simple but precision part. However for really smooth & accurate traveling it needs to run on 1/4" CRS flat bar, Still not that expensive as opposed to HR black finish strap or angle. The bearings look to be sealed so lubrication shouldn't be an issue. From my viewpoint It will tale 4 of them to do 1 rail.

For driving the table rack & pinion isn't that expensive either. When you price R&P as opposed to chain or belt be sure to include everything you need for each system. Belts & chain will require more shafting, bearings etc. The more of that you have the more friction your drive motors have to overcome.

Not that any of them are not solid effective systems. Just choose what's best for you.

In my case I wanted the longest life with lowest mantinence, take the least amount of space, withstand the most soot, grit, hot sparks. For me the choice was R&P.

When it comes to the electronics. I knew nothing at all about what makes a CNC table run. I chose to go with one of www.CandCNC.com (Torchhead's) PlazPak systems. Not the cheapest way to go but when you concider a digital THC & as plug & play ready as their stuff is the extra $$$ made good sense to me. I can also tell you that CandCNC WILL NOT leave you hanging out to dry if you have a problem. Tom's customer service is second to none in my book.

Even if you want to tackle building you own control cabinet It's not as hard as it looks on the surface. Just use good parts in there that at least have customer support. Also before you buy take time to download & read each different company's instruction manuals. Several Good drives & other electronics out there. Some of them have same as useless doccumentation with them. Even then you can always find help here.

Good luck & please start a build log of your own here for us to follow. It's been a while since a new exciting Torch or Plasma build has been well doccumented here. I get loads of enjoyment form everyones projects. Whether It's a How Cheap can I squeek by, or How rock solid & long life & "pretty" can I make it. There are tons of pictures & great table ideas over on the router build logs also. If you haven't browsed those builds be sure to give them a look too.

NEIL

millman, thanks for your replies. I have studied dozens of build logs. When I get suggestions like yours, something clicks and another piece falls into place. Then I go back to the build logs with a bit more knowledge and understanding. I've scanned yours completely 3 times and am figuring out more how and why questions each time.

I agree, Tom at candcnc is very willing to take the time to help with projects like mine. Where he gets the time I don't know. I plan to use one of his packages when I get to that point. The steel cut-outs on his other website are along the line of what I want to produce also.

I was thinking of using 4 of the bearing blocks(cncrouterparts) On a flat bar mounted vertically on one rail and 2 on the other mounted horizontally. I'd draw a picture if I could, but you probably see what I mean. I'm not sure how wide the bar should be or the horizontal spread between blocks, I may just order the parts and play with it for a while. As far as the gantry(y axis?) I think 2 blocks on either side of a vertical mounted bar should be stable enough. I plan on using a z axis like mlaws.

I think the r&p drive is pretty straight forward. Lots of tables are built with dual drive systems but Mike's gantry seemed very rigid and is driven only on one rail. I don't see any reason to have more equipment on this table than I need.

I am at the point where I want to start gathering components for my project. When I start to build I'll start a project log if I can figure out how!

By the way, is this an appropriate way to post or am I just gumming up weldtutors forum?

Thanks again, Don

ps. If any other rookies want to share ideas or frustrations feel free to let me know. D

When I start to build I'll start a project log if I can figure out how!

By the way, is this an appropriate way to post or am I just gumming up weldtutors forum?

If any other rookies want to share ideas or frustrations feel free to let me know.
To set up a new project log go from home pg, to forums, to CNC plasma,
then about 1 page down, below the various project threads posted, (just above Display Options), click on NEW THREAD.

For general questions or discussions not related to a particular persons project log, it is possible to start a new listing by clicking on the NEW THREAD under the existing discussion topics.

You might want to start a new discussion area topic something like, "CNC Plasma Ideas & Questions For Rookies"
If so, give it a try & when you might need set-up help, myself or others are available.

Big-D,

Here this will make it very simple for you to start a thread in CNC Plasma, EDM and Waterjet Machines to discuss your ideas & ask questions: http://www.cnczone.com/forums/newthread.php?do=newthread&f=62 Once you build your first piece then move over to: Plasma, EDM and other similar machine Project Log, & Keep everyone updated there. The more information & pictures you can post the better others can tell what you are doing & in turn help you with decisions.

Good post in #261 above Millman52.

That should help folks to start new discussions or post questions not related to a particular project log.
Certainly feel free to ask questions in a project log, that pertain to that project, or if you have difficulty starting a new thread. Most members here are quite flexible.

Questions & discussions = learning!

Info you posted in #258 is very informative Millman52.

Just so happens one already had your name on it.
-also already thinking about how to the fourth axis

See this thread (http://www.cnczone.com/forums/showthread.php?t=51756)Mike,
for a fourth & fifth axis picture idea in post #10!

Rearing horse in picture is 14" tall.

Standard bred is 15" overall length.

Each is welded to a small base.53211

Bruce
Keep the pictures coming!
mike

Wolf pictured here is 12" tall by 10" & sits on a base.

Angel fish is 8" long, edged in brass, with a hook for wall mounting.

Both have a moderate degree if intricacy & were cut quite well by the chain driven machine in this project log.

Hi Weldtutor,
From your picture. What material do you cut? SUS or steel. Why do your dog picture show black colour? Do you paint? I feel it has a beautiful surface.

Mongkol

What material do you cut? Do you paint? I feel it has a beautiful surface.

Thanks Mongkol. :)

The wolf (dog) is spray painted with a "hammertone black" paint that gives a hammer textured surface.

Fish is polished & swirl ground, then given 3 clear coats of lacquer.

Normal mild carbon steel (Not Stainless) is used for both items pictured.

The heron pictured is 38" tall overall.

Rooster is 20" tall.

The 2 little guys pictured here are each 4" long.

Patterns for them were developed in an attempt to CNC plasma cut quite small items with accuracy.

For fun you might want to print the picture & search for the differences in each of the items.

If you find at least 6 major changes you deserve a beverage. :cheers::cheers:

54510

This "Welcome Duck" is 22" wide.

The bird & text are slightly modified from the DXF that Switcher posted here (http://mydxf.blogspot.com/2008/03/welcome-duck.html).

Keep them coming Bruce, it is nice to see what your cutting.

mike

nice to see what your cutting.
mike

Thanks for the interest Mike.:)

This little old coupe has a 4" wheelbase.

Although "Gecko Drives" are doing a great job in my machines controls, the holder pictured here will actually be displaying antique auto plates. The coupe is to follow that theme.

Kerf between the running board & body is a nice .040" gap.

The horse head is 18" wide.

A steel shield shape, will be welded to the left straight edge, so the head projects out for a wall display.

Another member requested the DXF for this which is posted in the "Share Your Files" forum.

Dear Weld Tutor:)
After a long long time , i set and watch ur thread...I built my first machine taking some of your ideas :)... Now i saw ur progress and was amazed how trickly u used chain system on ur router... U r genious man...

One thing i want to know... what is the accuracy of your machine..and are u getting the circle exact size and round in shape:)

I think u r the one here at cnczone who is using chain system...

I love ur machine..

Best Regards

After a long long time , i set and watch ur thread...I built my first machine taking some of your ideas :)...

Thanks for the kind words Khalid. :o Sharing ideas certainly makes CNC Zone a great resource.

My chain driven machine does cut circles that are round. When the plasma consumables (electrode & nozzle) are in good condition accuracy tends to be in the order of .050". I am very pleased with the cut quality & accuracy!

There are several other plasma cutting machines shown elsewhere on CNC Zone that are now using chain drives.

This is the cut from a couple posts earlier.:rolleyes:

It is now mounted to a wall plaque for display.

Weldtutor,
I guess you are still not using a THC...does Sheetcam automate your pierce height and cut height code (and dwell times) or do you have to manually perform this in the g-code? I am converting an old machine over to plasma and I am using a roller head like yours so I am trying to get this all straight in my head. Please advise.

I guess you are still not using a THC...does Sheetcam automate your pierce height and cut height code (and dwell times)

My machine is still using the torch mount (roller head) as pictured earlier in the thread.

Sheetcam allows you to make a "TOOL SETTING" in which you specifiy pierce height & cut height. As well you can set preheat time, pierce delay, & pause at end of cut etc.

These variables are then included in the code that is created, so manual insertion is not required.

I wish you well with your conversion.:)

Since your torch is fixed in relation to the transfer balls ( I would guess that the fixed distance is your cutting height), how do you judge your pierce height? I would have thought that you bring the z axis down enough to compress the springs to account for sheet warpage, etc. and that would not leave any accommodation for piercing...please advise.

drafterman

how do you judge your pierce height?:confused:

With the setup being used the torch tip is fixed .010" above the lower surface of the transfer balls.

Prior to initiating a cut the Z axis is lowered .010", & this location is read into the control program as Z, "ZERO." When doing this the compensating springs become slightly compressed.

The pierce height of .190 to .250 is set in the g-code and this commands the Z axis motor to elevate to that position for piercing.
In so doing, the torch, mounting plate, springs, etc. all move upward together.
The pierce heigths are suggested in the Thermal Dynamics instruction manual, rather than being "judged" by the operator.

Thanks Weldtutor, I wasn't sure how far you were compressing the springs at your zero height. I noticed that in Mlaws thread he has a switch for sensing the material (zero height). It sounds like you are not using this, correct? I use a similar switch on my router and I think it will work the same way by providing feedback to Mach to zero the Z axis.

It sounds like you are not using this, correct? I use a similar switch on my router and I think it will work the same way by providing feedback to Mach to zero the Z axis.

That's correct.
A setup like your router should be suitable for the way you plan to configure your plasma conversion.

Tundra swans pass over my home on their 6000 mile spring migration to their summer breeding grounds in the Canadian Arctic. :rolleyes:
They have a 5 1/2 foot wingspan.

Swan in the picture below is 18" overall.
Kerf at lower wing edge is .045".
Swirl polish has a clear lacquer finish.

This wind spinner was cut from 16 ga. mild steel, 10" O.D. & has a polished finish.

Original file was posted by another member in the "Share Your Files" forum.:)

First photo is when first cut & second is completed spinner.

very fine job done on wind spinner:)...intricate part with home built machine...thanks 4 sharing weldtutor

Thanks Kahlid.:)

The first picture is a variation of the previous spinner with a humming bird now in the center.

Second is a butterfly spinner.

Final shows the item directly after being CNC plasma cut.

how the backlash is controled as i saw gear box is also fitted

Thanks for your interest Sanjiv.

The speed reducing gear boxes used are quality units without any apparent backlash introduced into the operation of the drive system.

Earlier in the thread it is noted that allowance has been made to adjust the chain drives to reduce slack there, as is the case with those applications using timing belts.

very beautiful work on Wind spinner:)... I think u have a good wind their...

These 2 cuts were from DXF's created by CNC Zone member Switcher. Thanks:cheers:

Owl is slightly modified & 10" X 13."

Star is 10" O.D.

Both are cut from 16 Ga. steel.

Nice work!

That owl really stands out.

Everytime you post your plasma projects, it makes me want a cnc plasma table. :)

.

beautiful work:)...are u selling or making them for ur own interest n hobby?

Thanks Switcher.
I was very pleased with the way the owl DXF worked to make the actual cut.
Your files are certainly appreciated.

CNC plasma cutting is primarily a hobby for me. Thanks Khalid.
Prior to building my machine I did a lot of research here & was given much help by the members.

My enjoyment & creative satisfaction now comes from modifying or drawing files for the machine as well as the actual cutting & finishing of the work pieces.

I am still amazed that electronic controls fitted to a mechanical device are able to do work that previously was only done manually.

Hi
First let me introduce myself. I have a computer + fabrication background. I have welding equipment (TIG + Stick + gas), small lathe and just about anything I may need (except a Mill). I am considering building a plama table for awhile and I have read a number of threads and downloaded Mike Laws plans.
I am going backwards and forwords between using ACME + AB nuts and Chain Drive.
The question that I have is why the reduction gearboxes? Is this because of the use of small servo motors more torque is required? Is this a direct result of using a chain drive? I am leaning towards using Amtek 38 servo motors and I am not sure if I will still have to use a massive amount of reduction between the motors and the actual chain drive.
WeldTutor I see that you sunscribe to the KISS principle and I really appreciate that.
Great work and thanks for all the info.

Tony

The question that I have is why the reduction gearboxes?

Hi Tony, welcome to CNC Zone! :wave:

Your background should serve you well to build a CNC plasma table. The plans that Mike Laws' has freely shared were a great inspiration for me.

An Acme threaded shaft that is unsupported over any significant length, spinning at the speed used for most plasma cutting is subject to "whipping" & thus undesirable vibration. The smaller the diameter of the shaft, the greater the degree of this problem.

My choice of drive chains & sprockets was based upon local availability of components & familiarity with the method. The results obtained continue to exceed my initial expectations.

The servo motors I used are rated at a max continuous speed of 4000 RPM's.
Calculating a motor operating speed of 50% of the above, with a 3" sprocket, 60:1 speed reduction, gives the machine's X & Y speed of movement capability in the 350 to 400 IPM range. Speed was more a consideration than torque, which certainly was increased by the reduction.

Amtek 38 motors are normally rated at 1140 RPM's & therefore would require much less speed reduction for your application. I believe CNC Zone members Beetman & Smile Wizard both used these motors on their chain driven plasma tables.

Thanks for your kind words. WT

Thank you for your reply. I am still a bit fuzzy about the gear reduction. Doesn't the controlling software (eg Mach) allow you to adjust the speed of the motors?
Thanks
Tony

Think autos. You only have one gear on a CNC. If your intent is to cut at 300 IPM or less, setting it up to have 12,000 IPM and tuning it back in software is like having your car's transmission stuck in overdrive and drive 30 MPH. It reduces your resolution, it reduces your torque and it gives you speeds you can't use. Yes the velocity setting in MACH allows you to set your max velocity for any motor and configuration. But just driving it slow does not mean you don't give up important parameters.

If you have a manual (stick shift) gearbox on your car or truck put it in 5th gear and drive around town. You can limit the top speed with the accelerator but you will find your acceleration and control are dismal. To perform better it would make more sense to be stick in a gear that better matches the needs of the mission. So would you rather have a car that will run at 500 MPH to drive to the store or one that is optimized to go 50 or less?

In CNC cutting you need things like acceleration (makes for square corners) and resolution. Direct drive to a pinion or sprocket/pulley multiples the ratio UP and costs you both torque (reduces available acceleration) and resolution (reduces accuracy).

Even with steppers, belt reduction is recommended. Even though they spin slower and have better torque the slower they spin, the pinion/sprocket will cost you torque and resolution from a motor that already has lower numbers of each. A stepper motor direct coupled to a 1" dia pinion moves the load 3.1416 inches per rev. Given the raw resolution of a stepper is about .005 that costs you 2/3's of your resolution (now at .015). Other factors multiply on top of that raw number to give you final accuracy. While it's true that plasma is not a precision cutting operation starting out with accuracy of a machine at .030 or worse will be worse than you can hold with conventional plasma.

Servo accuracy can be increased by using a higher count encoder but that too comes with trade-offs.

TOM CAUDLE
www.CandCNC.com

Tom,
Thanks for a great answer & automotive analogy.:)

A summary Tony, might be that the geared speed reduction, increases both (resolution) accuracy & (acceleration) control.
WT

Thanks for the reply. I sort of suspected that this was the case.
Now I see relatively small ratios used (3:1-5:1) being used on lead screw type tables where chain driven table are more like 30:1+. Is this because
a lead screw arrangement gives you increased torque multiplication and resolution by it's own inherent design vs. the chain drive?
I would like to go with chain drive but the costs of acurate gearboxes seem to exceed just about the total cost of the remaining comonents of the table . If a couple of gearboxes where to fall out the back of a truck in front of my house, I would be ordering sprockets tomorrow. Is there a place that sells these cheaper?

Again thank you
Tony