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dnelso
05-25-2009, 10:11 PM
I have studied alot of nice plasma tables on the site and decided to build my own. I wanted a water table to cut down on smoke and warping. I also wanted to be able to empty the table for cleaning. I made an aluminum box that holds about 90 gallons of water and have a 110 gallon storage tank.Ther is a 3000gph pump in the storage tank. Takes about 2.5 min to fill table. Plasma cutter is hypertherm 1250. Used a g540 geckodrive and 50volt ps. rack and pinion drive with 3.75:1 reduction.
Have any questions just ask.
Dave

CNCCajun
05-26-2009, 12:23 PM
Very nice, clean . . . appears to be well thought out . . . I do have a question. On your gear reduction units, I see the motor, large cog wheel & ???? . . . What is the square looking unit on the same axis as the large cog wheel?

Steve

Weldtutor
05-26-2009, 12:53 PM
A great looking project!
Thanks for posting the pictures.

What motors were used?

millman52
05-26-2009, 05:02 PM
. . . What is the square looking unit on the same axis as the large cog wheel?

Steve

I'm betting on the square housing up 2 bearings to support the large notched pulley & shaft.

Just a guess.


Looks really good. From what of it I see should be a tight table that will hold close tolerance. & be repairable down the road if necessary....:cheers::cheers:

dnelso
05-26-2009, 06:25 PM
Millman52,
You are correct.The shaft is 1/2 and it has tapered bearings on each side of the block and then the small gear. I will take some pics of the first design. It was a pivot design, bushing on one end and spring pulling gear to the rack on the other end. I had some problems with accuracy and teeth skipping on the rack with high rapids. I had to run such a stout spring to keep from skipping I worried about premature rack failure. I also had bending of the pivot shaft that was also causing me grief. This design was alot less parts and machine work and works better. The motors are Keling kl23h284-35-4b.
Dave

Dustin407
05-27-2009, 08:25 PM
dnelso,

I must say it is a beautiful build. Everything looks first class, and looks well thought. Did you cut any parts yet? I would like to know what your tolerances are? Thanks for the post/pics.... Dustin

dnelso
05-27-2009, 09:53 PM
Dustin407,
The repeatability of the table is very good within a couple of thou. I have about .003 backlash in the x and y axis. I think unless you get hardend and ground rail thats the best you can get. I have cut lots of small parts and a few large pieces. After you get the torch height control and settings worked out you can cut parts that are very close to your drawings. Here are the pics of my first design belt drive.
Dave

Mongkol
05-30-2009, 10:32 PM
Dave,
It's a very nice machine.I am thinking to build CNC plasma machine with water table same as you.
I am little puzzled and have some questions.
1) It sounds like you use 2 motors on X-axis( left and right).yes or no?
Hybrid stepping motor? What torque is used for both X and Y axis?
2) I don't know what raw material is filled in the water to protect rust on steel.
Could you share this detail?
3)Do you use THC for your plasma table?

Hope your help
Mongkol

Torchhead
05-31-2009, 05:01 PM
Dustin407,
The repeatability of the table is very good within a couple of thou. I have about .003 backlash in the x and y axis. I think unless you get hardend and ground rail thats the best you can get. I have cut lots of small parts and a few large pieces. After you get the torch height control and settings worked out you can cut parts that are very close to your drawings. Here are the pics of my first design belt drive.
Dave


It's ashamed to waste that beautiful piece of work running with an old analog THC :p

Contact me off-line and I will give you a VERY generous trade-in on that THC300 and Port 1 Breakout (whoever it came from) for a new Digital THC and Single Port control (MP3000-DTHC) It will give you the precision and features to match a really nice build!

The MP3000-DTHC displays and is controlled 100% from the MACH console (screens) so you can simplify and clean up your Operator Controller and UI

Tom Caudle
www.CandCNC.com
www.CandCNC.com/MP3000-DTHC.htm

dnelso
05-31-2009, 10:23 PM
Mongkol,
1. The x axis left to right has one motor and the y front to back has two motors .The other motor in the pic is the z axis. The motors are from keling 387 oz-in KL23H284-35-4B.
www.kelinginc.net/SMotorstock.html
2.The table has an .100 thick aluminum tray that holds the water so it cant rust.
3. Yes i do run torch height control.
Dave

Mongkol
06-02-2009, 12:55 PM
Dave,
Thanks for the information. Here's the first machine of your or not.

Mongkol

dnelso
06-02-2009, 10:12 PM
Mongkol.
This is my first plasma table.I have converted a mill to cnc using mach and servos and built an engraving machine using stepper motors. I try to build machines that i need and study other machines before i build them. I enjoy building them and saving a few dollars.
Dave

Steve_Watkins
06-05-2009, 10:59 PM
Very nice machine!

Do you have any drawings or details on how you made the water table?

dnels
06-08-2009, 01:19 PM
Steve,
The table was drawn in solidworks. It would take some time to convert the model to DXF drawings. I would have paid for a design that i thought looked good and included all the part numbers. It takes alot of time to design and source parts.
Dave

Med-Pac
06-08-2009, 02:14 PM
Nice build, any chance of a video?

Mike

CNCCajun
06-08-2009, 03:06 PM
Again, your table is very nice. I realize that you have a considerable amount of experience in building something like this.

But, I do have a few questions . . .

1. Are your drives gear or belt reduction. If gear, did you buy them? If belt, how are they setup. A picture would be really nice.


2. As to the linear rails you have on each side. Did you have to mill the square tube they are mounted to, or is that type of rail rigid enough to be able to ignore irregularities in stock square tube?


3. The most puzzling to me is how did you get the rails parallel in both planes. I could see if the rails were top mounted, but the side looks very hard to do.

If anyone can answer or add to, I sure would appreciate it . . .

Thanks,:)
Steve

dnelso
06-08-2009, 09:43 PM
Steve,
It is belt drive reduction. I will take some better pics of the motors and the gears.The dust sheild cover makes it hard to see. The square tubing does not need to be machined. I welded the frame first then made a stand with a digital caliper on it for checking the height of the linear rail on both sides off the ground. It is very hard to drill the holes for the rails first because when you weld the tubing there is always some warping. Once the rails were mounted i machined a 1inch spacer 3 feet long to go under the rail then clamped the rack to it then drilled and tapped the holes. Because i use no spring to pull the motors to the rack the spacing is critical. If the spacing is off you would have tight spots and loose spots along the travel. Keeping the rail clean was another reason for mounting on the side. Plasma cutting is very dirty.
Dave

CNCCajun
06-08-2009, 11:26 PM
Steve,
It is belt drive reduction. I will take some better pics of the motors and the gears.The dust sheild cover makes it hard to see. The square tubing does not need to be machined. I welded the frame first then made a stand with a digital caliper on it for checking the height of the linear rail on both sides off the ground. It is very hard to drill the holes for the rails first because when you weld the tubing there is always some warping. Once the rails were mounted i machined a 1inch spacer 3 feet long to go under the rail then clamped the rack to it then drilled and tapped the holes. Because i use no spring to pull the motors to the rack the spacing is critical. If the spacing is off you would have tight spots and loose spots along the travel. Keeping the rail clean was another reason for mounting on the side. Plasma cutting is very dirty.
Dave

The only part that was confusing was, "I welded the frame first then made a stand with a digital caliper on it for checking the height of the linear rail on both sides off the ground. " . . . Did you use the floor as a reference to level the rails . . . .???

Steve

Steve_Watkins
06-09-2009, 09:01 AM
Steve,
The table was drawn in solidworks. It would take some time to convert the model to DXF drawings. I would have paid for a design that i thought looked good and included all the part numbers. It takes alot of time to design and source parts.
Dave

Oh I totally understand :) Your machine looks good enough to market the plans... I would be interested if you decide to produce them...

I was mainly interested in how you made the water table water tight... Sealant or did you wield the joints...

dnels
06-09-2009, 01:20 PM
Steve,
The table is one piece and it has 3 welds on each end. One in the center and then the corners.
Dave

Dustin407
06-09-2009, 02:51 PM
Dave,

Just wondering if you have any construction photos(begining,middle,end) of your build. This might help to clarify the process and procedure you took to build this machine. If you do that would be great....

Thanks, Dustin

dnels
06-09-2009, 09:54 PM
I dont have any pics of the constuction but i do have a vid . Its cutting .023 sheetmetal at 150ipm. Torch height control is on
YouTube - plasma table. I will try to take some pics to explain constuction.
Dave

dnels
06-14-2009, 02:22 PM
Some more pics of 1/2 plate. Cuts very nice. Last pic is of the backside with very little slag.I also added a pendant for manual control. Got it at walmart for 45 dollars. You can map any function with mach3 that you want to control. It has 2 joysticks so i have one setup for front view control and the other setup for when you are standing on the side of machine. I use it for cutting sheets and to zero parts that are away from the keyboard. Mach3 has a program named keygrabber that is built in for this purpose. Hossmachine.info has some nice vids for explaining how to setup this function. YouTube - plasma table
Later Dave

dnelso
08-16-2009, 05:45 PM
Just a few pics of a seat back for a bench. Material is 3/16 thick. Pics are before cleanup. Very little dross on back side.

DanOSB
08-16-2009, 11:38 PM
you built a really nice table very clean job..

also could u post up the finished picture of that bench as im interested in building one to make my wife happy :)

Mongkol
08-17-2009, 01:59 AM
Dave,
I try to zoom in your picture and close up the edge after cut.Pls see on the highlight.From the looks of the corners,do you have a problem of wiggle? The edge is smooth or not?

Mongkol

dnelso
08-17-2009, 06:56 AM
Mongkol,
What you see in the picture is dross. The cuts are smooth. I will post pics after i clean it up. Some could be pic resolution. I used phone for pics.
Dave

dnelso
08-30-2009, 09:01 PM
Found some time to skin the sides of the plasma table. Also worked on the bench.
Dave

Mongkol
08-31-2009, 07:34 AM
Dave,
Really professional, How to eliminate dross? Sand grinder?

Mongkol

dnelso
08-31-2009, 09:15 AM
Mongkol,
Most of the dross can be knocked off by just dropping on a steel plate. I have a blast cabinet that i use for small parts. Large parts i use a heavy paint scraper
and the 3 inch sanding disc. Saftey glasses are needed at all times when knocking off dross.
Dave

DanOSB
08-31-2009, 05:14 PM
wow your bench looks awesome..

If you dont mind could you send the dxf file of your bench

you do really impressive work finishing up all details on ur cnc machine..

for my machine i havent finished painting the gantry to the color i want (its aluminum) and i dont even have skirts or anything.. been too busy with other projects at the shop..

Cheers
Dan

dnelso
09-05-2009, 05:54 PM
Finally finishing bench.
YouTube - 1/8 steel
Dave

titto
10-05-2009, 05:10 PM
Veramente complimenti sia per la macchina che per la qualità di taglio.:)

WSS
10-05-2009, 11:08 PM
Veramente complimenti sia per la macchina che per la qualità di taglio.:)

"Really compliments for both the machine and the quality of cut"

microdot
10-24-2009, 09:51 PM
Dave,
Very nice table. Can you provide some detail on the head/torch assembly? In your latest video I see the 2 sets of linear bushings move independently and that the top set seems attached to the Z ball screw (I assume you use a ball screw) while the bottom seems fixed to the torch carriage and can move against the limit switch when descending for the THC? is this correct? What type of mechanism do you use to allow that sliding?

thanks.

dnelso
10-24-2009, 10:08 PM
Your description of how it works is correct. Here is the link to k2cnc http://www.k2cnc.com/shop/proddetail.asp?prod=6in_K2_Plasma&cat=33.
It cost 395.00. i added up all the parts that i would need to build it and it was cheaper to buy it from them.
Dave

dnelso
11-12-2009, 10:34 PM
YouTube- 090 alum

pimpbike
11-12-2009, 11:30 PM
Very nice machine congrats!

adscnc
11-21-2009, 03:57 PM
Hi Dave

Great looking machine, what size profile rail did you use ? is 25mm 1"

Cheers

Al from England

dnelso
11-21-2009, 11:26 PM
Thanks
Yes the rails are 1 inch 25mm

Switcher
11-22-2009, 12:06 AM
Great looking build!

Do you have a filter when cleaning out the water table?

dnelso
11-24-2009, 08:50 PM
Switcher,
I dont have a filter. I have a screen in the drain that catches the big stuff.
I put the drain on the opposite end of the table that i cut on so not much debris anyway. I drain the table every day after work and once a week use a shop vac to pick up the debris. So far so good
Dave

BTA PLASMA
11-25-2009, 07:08 PM
Ooops :)

BTA PLASMA
11-25-2009, 07:09 PM
Fantastic table!

Boogiemanz1
11-29-2009, 11:41 PM
Dave, that is a first class rig. I am jealous after looking around your shop. It is very nice. As someone else mentioned, I would most likely buy a set of plans and list of materials if they were offered. Thanks for sharing............jb

multiplex
12-18-2009, 09:16 AM
seriously nice machine you have built there.

so does your water pan drop into the frame assembly?

at this point, anything you would do differently?

dnelso
12-18-2009, 07:57 PM
Multiplex
Yes the water pan drops in the frame and is held in with the angle iron.The pan is made of .090 alum and the sides are are bend up so there is only 4 small welds in each corner. It doesn't require any sealant. I cant think of anything i would change. I have cut stainless, aluminum, steel and also used it as a router with no probs.I have some vids of the router cutting that i will post soon.
Dave

dnelso
02-18-2010, 10:00 PM
1/2 steel plate 27ipm 60 amp tip.
YouTube- plasma cutting steel
Almost time to change slats..

microdot
02-19-2010, 09:41 AM
Nice! That is a better finish than I would have expected. Very clean.

panozeng
02-20-2010, 09:41 AM
Dnelso - that is a really nice build! In the first pictures do I see a large surface plate in the background? One that is on the floor and just the right size for doing automobiles? It looks just like the style plates I've seen in lots of shops around Charlotte, NC... What kind of work do you do?

That plate must have been handy building your table!

adiozmm
02-28-2010, 11:47 AM
Hi, how you do it with the start of the torch to the plate.
Because of this every time the ignition on the plate is stationary.

scrambled
02-28-2010, 12:09 PM
I like your plasma cutter.

It looks like it cuts great! What plasma cutter are you using?


Steve

dnelso
02-28-2010, 08:42 PM
Scrambled the plasma cutter is a hypertherm 1250. The consumables last a long time. I use a MP3000-THC torch height control from candcnc.com.
Adiozmm,
The torch goes down and senses the plate them moves up and fires the torch waits till plate is pierced them moves to cut height and starts motion. i hope this answers your question.
Panozeng,
That is a 10x20 surface plate. I do work in NC. We build race car chassis for nascar series.
Dave

Torchhead
03-01-2010, 11:43 AM
With an integrated THC into MACH3 the moves to do the touch-off (IHS), pierce height, plunge to cut height, rapid Z height, and any delays are part of the Z toolpath generated by the custom POST for SheetCAM. Since MACH actually controls the Z (not the DTHC directly) it can be used to make any series of moves you want, both before and afterthe actual cut (where the DTHC tells MACH what to do with the Z). Because MACH knows where the Z is at all times, you can issue absolute moves and it makes them.

So a g-code sequence like:

M05 (turn off torch)
G04 P.50 (Pause for 1/2 sec)
G00 Z 1.000 (raise Z to safe height)

Would be put at (by the POST) at the end of the Cut.


Using a non-integrated THC (aka stand-alone) all of the Z moves are under control of the THC logic and are not part of the toolpath. Indeed no Z commands are even allowed from g-code.

TOM Caudle
www.CandCNC.com

pimpbike
03-13-2010, 03:26 PM
Dave, was that shop air you were using when cutting the aluminum? Also what was the thickness?

dnelso
03-15-2010, 10:05 PM
pimpbike,
I use shop air and i was cutting .090 alum

HamerDownJustin
03-16-2010, 02:08 AM
This machine is nicer than most I have seen for sale..congrats

balimach
03-25-2010, 07:38 AM
Its awesome, really..really awesome...

I`m newbie here. I have to learn a lot to all of you guys. Is it Ok with you, if I as foreigner from the other country join in this thread?? If you don`t mind...

I trying to build one, but is so hard to find part source in my country, I have to search and get import overseas. and it take more longer in shipment.
Good for you can easily get sourcing in USA.


Thanks for sharing, Dave.

balimach
03-25-2010, 11:28 PM
Dave,

I have few question;

1 )
You said that X axis from R to L you use 1 motor ( on the Left right ?) so, there is no motor in the right? & you use 2 motor to move forward and move back. Why? I tough we should use 2 motor in the R & L, and use 1 motor for Y axis.
Can you explain bout it?

2 )
What is the material you use for the gantry? is it big Hollow/square bar? or you made it with welded & machining plate ? What is the size for the gantry which is strong enough?

3 )
For the linear guide, What brand do you use in your table? If I not wrong, the linear rail is max. 50 mm long, So its mean if we want to build 3000 mm table. we should attached 6 pcs of that rail? if that so, how to keep it flat?

4 )
For the THC, I see the ballscrew between 2 rod, what is the function?
You use the machine torch, is it additional order or is it one whole package in powermax1250? I ask to buy it in my country, they just giving me an ordinary hand torch, if I want a machine torch, we have to buy optional order.

5 )
I see no burr of the steel you`ve been cut, I just wondering if I not use a water system as you are, can I get the same cutting quality like you have?


Best regards,


Harry

AndiKid
03-27-2010, 08:19 AM
Dear Dave,

first off I want to say that this is my first post and I would like to say hi to everybody in this great forum.

Your machine is so so so amazing and inspiring and I thank you for this great thread. Also I would like to thank you for being so kind and answering so many questions and helping others with information about your machine.

I would like to kindly ask you if you could maybe post a picture of the belt drive system, reduction, bearings and so on.

As you wrote in a post before it can't be seen due to the dust protection and I think it would be just great to see the mechanism for me to understand what makes this machine actually move.

I hope you can find the time and again thank you so much for all your great support and kindness with people asking questions.

Best regards

- Andreas

Lockdown
04-05-2010, 06:27 PM
dnelso,

Again as said by many wonderful job on the machine.

I'm currently in process of designing my table on Solidworks and I am very curious as to your side rails and how you attached everything to move. If you could post more pictures of some internal parts not seen on the other pictures that would be great.

Again thanks for the inspiration for my build.

dnelso
04-06-2010, 04:32 PM
Sorry all for not answering post lately. I have been down for the count with back surgery. I will try to get caught up on recent questions and see what i can do. Wont be back to work for couple more weeks so i cant take any pics.
Later Dave

Boogiemanz1
04-06-2010, 05:12 PM
Dave good luck with your recovery. I am about to start my first attempt at a plasma table which I hope resembles yours. I would be the first in line for a set of plans if you sold them.

AndiKid
04-18-2010, 10:16 AM
Hey Dave, I am very sorry to hear that you had to undergo surgery. I hope you will recover soon.

Maybe you could tell me quickly if you built your gantry out of steel or aluminum. I read that it's supposed to be light but yet on your pictures it looks like it's made of steel like the rest. If you chose steel.. why did you chose it?

Thank you and greetings from Berlin

- Andreas

dnelso
04-18-2010, 01:06 PM
Andreas,
I chose the steel for a couple of reasons. My plans are to use the table with a router as well as plasma so i wanted the extra strength for machining aluminum and wood. It was also nice for mounting the rack because i could tap the holes and not have to weld the rack to the gantry. If i was going to use plasma only they have some nice aluminum extrusions that have fastening systems for mounting the rack and pinion.
Dave

AndiKid
04-19-2010, 06:12 PM
Dear Dave, thank you so much for your fast answer.

Have you already used your machine as a router? It must be difficult to change the setup, no? That would be really amazing to use it for both plasma cutting and routing.

About the aluminum extrusions. Do you mean these rack clamps to put the racks on the extrusion http://www.cncrouterparts.com/product_info.php?cPath=21&products_id=64

Because I like the idea of the extrusions but I just love the look of your machine built rock solid from steel.

Another quick question you can maybe give your opinion on..

Would this product work on building a machine like yours? Unfirtunately the R&P of your machine is so difficult to see..

http://www.cncrouterparts.com/product_info.php?cPath=24&products_id=65

Again all the best for your recovery and thank you so much for giving me and all of us folwing this thread information and support.

Best reagards

- Andreas

dnelso
04-19-2010, 10:56 PM
Andreas,
I have used it for both. Its not hard to change over maybe 15 mins.
here is a vid of it running the code after i cut it.
YouTube- plasma table engraving

dnelso
04-19-2010, 11:00 PM
Andreas

The parts you are looking at will work fine. I used rack and pinion from mcmaster carr.
Dave

Black Pearl
04-28-2010, 08:25 PM
Dave,

Amazing build as everyone has said. What linear rails and guide blocks did you use? Where did you track a 10' rail down or did you use 2 shorter rails?

dnelso
04-28-2010, 09:55 PM
the rails and block came from automation4less. They are from hiwin
Dave

guydrisc
04-29-2010, 01:16 AM
how much money you think you have invested in that bad boy?

dnelso
04-29-2010, 10:31 AM
I have about 6,000 dollars in it including the Hypertherm 1250 plasma cutter. The steel i had on hand so that's not included.
Dave

AndiKid
07-17-2010, 07:25 PM
Dear Dave, I hope this finds you well! Unfortunately you haven't been able to be around in the forum it seems. I hope you are ok.

I am trying to start my project but one thing is still giving me a headache. The R&P Drive..

Could you maybe please please post some pictures of your drive and maybe some more information on it?

Thank you so much and all the best

- Andreas

Boogiemanz1
10-13-2010, 12:08 AM
Hi Dave, I hope you have fully recovered from your back problems. I am finally beginning to get serious about a plasma table. I read that you used the Hiwin slides, and am curious as to how they are working out for you, and which ones you used on your table. I am also going to use the K2 Z setup.

With your water table are you finding much residue in your shop from the plasma cutting? I would appreciate any advice you have on th subject...thanks..........jb

MBG
11-02-2010, 07:59 PM
Just curious why did you use a gear reduction? I have seen some machines where they are direct drive.

What are the pros and cons of these two systems?

Boogiemanz1
11-03-2010, 12:33 PM
I am trying to figure out the gantry extrusion and the K2 Z Axis travel length that I need. In the posts Dave, indicates a 6" floating head Zaxis by the price he quotes. If his linear slide is much bigger than a 30 MM or his Z is maybe a 4" travel and not a 6". I am going to buy an 80 X 160 mm aluminum extrusion (3x6") if it is a 6" , and a 2x4 " extrusion if it only a 4. What do you think? I am going to use the new Hypertherm 85 with a micro machine torch which is much shorter than the older style machine torch. I am afraid that my machine won't work well if my gantry is too heavy. How high do most guys make the gantry ......jb

BTW, I just got a box from CandCNC with my bladerunnersetup in it.....jb

Torchhead
11-03-2010, 06:29 PM
Just curious why did you use a gear reduction? I have seen some machines where they are direct drive.

What are the pros and cons of these two systems?

If the final drive is rack and pinion you first have to realize the effect is a STEP UP in Speed (calculated as a ratio , of PI times the pinion Dia). Thus a 1" dia pinion results in approx a 3X speed increase and a 3X torque and resolution DECREASE. If you take that a stepper will spin (based on the DC applied voltage) of 600 to 800 RPM with a moderate load then you have a theoretical linear speed of 1800 to 2400 IPM with direct drive. Downside (con) is that you traded 2/3's of your torque and resolution for speed you may not be able to use.

So why do you need torque? because torque translates to lateral force and that yields acceleration (or cutting force on contact cutting operations). Why do you need acceleration? because with plasma to do rapid turns, starts and stops (to get sharp corners) you need good acceleration. Acceleration is the process of moving a Mass (weight of the gantry) from one speed up or down to another in a period of time. The lighter the gantry the faster you can accelerate the mass given a set torque. Conversely in order to accelerate a heavier gantry faster you have to have more torque (force).

So the Pros and Cons of a gear/belt reduction:

Pros

Better matches the RPM of the motor and the torque to a given load
Reduces mechanical vibration from motor to load.
Will accelerate a given load/weight faster.
Increases resolution (smallest distance you can move in one step)
Allows smaller motors to do more

Cons

Costs more.
Adds more complexity (more things to wear out and break)
Reduces speed to sub-sonic levels so you can't brag to your friends about how FAST your table is.
May not be needed if you can achieve acceptable acceleration numbers (min 15 IPS/sec) with a given load.


To gain back the lost torque and resolution you trade back some speed. A 3:1 belt reduction gets you back to base motor specs (with the 1" pinion) so you have 3 times more torque, 3 times more resolution and 1/3 the speed (about 600 to 800 IPM). More reduction gets you more resolution but because of the nature of steppers a diminishing amount of added torque. Generally numbers over about a 3:1 overall reduction (step down + step up of pinion) don't offer a lot more in return.

So.....some systems with direct drive will work fine depending on the gantry weight, motor torque ratings and the type cutting. You may have to compromise as the weight increases by lowering the acceleration targets and living with rounded corners.

It's all about matching the mechanics to the job at hand and motors you have to do it with.

TOM caudle
www.candcnc.com

AndiKid
11-08-2010, 07:18 AM
Hi Tom, thank you for this ver nice answer. Can you tell me the rpm of the 620oz Steppers of your Dragoncut Package?

Also they are 3,4A that I know, but are these Amps at 48V? Do you maybe have a 3D Cad File of the motors?

dnelso
11-08-2010, 11:22 AM
Hello all,
I have used my plasma table for over a year now and decided to take a look at the gear reduction and check for wear and see if all is well.it was dirty as expected but no real signs of wear. I took some pics so people would see how it works.
Dave

dnelso
11-08-2010, 11:25 AM
here are the rest

dnelso
11-08-2010, 11:31 AM
Boogiemanz1
I bought the 6inch z axis and cut it down to 4inches. I only cut flat sheets so 4in was plenty of travel
Dave

AndiKid
11-08-2010, 12:17 PM
Wow!! Now it's really possible to see and understand how much thought and excellent engineering ypu put into this. This is really awesome and very nicely executed.

Could you maybe explain the benefit of the tapered bearing?

dnelso
11-08-2010, 12:44 PM
I used the tapered bearings because i wanted to eliminate all the areas for possible backlash. I had a bunch of 1/2 id bearings laying around so that's what i used. I had looked at gear box reduction but after i saw the price i decided to just build it myself.
Dave

AndiKid
11-08-2010, 12:50 PM
so that means, that you machined tapered "receivings" (don't know how to call it correctly) into the holding plate?

dnelso
11-08-2010, 12:54 PM
its a pocket machined in the alum block then the bearing race is pressed into the pocket

AndiKid
11-08-2010, 01:00 PM
but this pocket has a cylindrical shape or the tapered shape of the bearing?

Torchhead
11-08-2010, 01:23 PM
Hi Tom, thank you for this ver nice answer. Can you tell me the rpm of the 620oz Steppers of your Dragoncut Package?

Also they are 3,4A that I know, but are these Amps at 48V? Do you maybe have a 3D Cad File of the motors?


Stepper RPM comes from voltage. At 48V they are about 600 RPM
Stepper current is controlled by the motor drive (on so called "chopper" drives). Motor torque comes from current. Running them over their current rating tends to cause overheating and a diminishing set of returns. Steppers are basically current devices (actually wattage devices). You fix (limit) the current and Servos are basically voltage devices.

The motors are high efficiency and are rated at 3.5A per phase. We had the motors specially engineered for the Gecko 250 series drives for optimal performance.

TOM caudle
www.CandCNC.com

AndiKid
11-08-2010, 02:48 PM
Thank you very much Tom for your answer! So basically the motors have 163 Watts, correct?

I have another question though.. I bought the 620oz. Dragoncut Package. I want to use my machine for routing Aluminum and plan to use a 3,6:1 gear reduction.

Is that possible or do you recommend an alternative?

P.S. Do you have a 3D File or a 2D Sketch?

Torchhead
11-08-2010, 05:55 PM
Thank you very much Tom for your answer! So basically the motors have 163 Watts, correct?

well....sorta. Watts is a measurement of work over time. The full current at the 48 volts would only be drawn at full load (motor stalled). Since Watts is basically volts X amps x duty cycle by raising the volts you automatically lower the duty cycle which lowers the RMS current.


I have another question though.. I bought the 620oz. Dragoncut Package. I want to use my machine for routing Aluminum and plan to use a 3,6:1 gear reduction.

Is that possible or do you recommend an alternative?

All depends on the diameter of the pinion gear, the thickness and type aluminum, and how deep you cut per pass. The weight of the gantry is part of the "load" but only factors in during acceleration.



P.S. Do you have a 3D File or a 2D Sketch?


Contact me direct (tom(at)CandCNC(dot)com) or via the CandCNCSupport forum on yahoo. I have engineering drawings 2D of the motors.

Boogiemanz1
11-08-2010, 06:57 PM
Wow Dave, I thought I had your gearbox, gantry holder figured out...I had missed the adjustments. I kept trying to size that z-axis and then ordered a 4.5 ". Would you set my mind at ease and tell me what slides you used and if they are working well? Thanks again..................jb

dnelso
11-08-2010, 07:05 PM
I used hiwin 25mm rails. I got them from automation4less.com
Dave

AndiKid
11-08-2010, 07:06 PM
Are you looking for the type he used? The size he used is 25.

AndiKid
11-08-2010, 07:19 PM
:) Dave's got it already.. Also I think I now understand about the bearing. The shape of the complete bearing is zylindrical I now saw some on a website. What I don't understand is, why they are better than normal bearings but I guess that's because I studied Mkt. and not engineering :)

Boogiemanz1
11-09-2010, 12:08 AM
Thanks guys, I'm on the right road now, Andreas, Most of the time tapered bearing sets are used in high load application where they can be used to set end play....................jb

dnelso
07-13-2011, 11:53 PM
Im building 2 new tables. One will be a 5x5 and the other will be a 5x10.
i will take pics as they progress.
DAVE

Shed Hunter
07-14-2011, 10:49 AM
Great build. Very clean.

So, if I read correctly... The first spring loaded set-up on The X Axis did not work correctly, & now the drive system is fixed?

dnelso
07-14-2011, 05:07 PM
i didnt like the spring loaded version shed. i had more backlash than i wanted . my new version works just fine

Boogiemanz1
07-26-2011, 12:35 AM
I am glad to see you active on this part of the site. I am 3/4 of the way done with my table that is taking it's inspiration from yours......I copied everything I could ;) I did use 1x3 T-slot extrusion on the sides to make it easier to keep the slides and gear rack parallel since I don't have acess to a floor plate. I found that everything relied on the position of the rack in my case. I'll be watching for your new builds............jb

dnelso
07-30-2011, 09:59 PM
i decided to build 2 5x10 one for a friend and the second one for the house prob will start a new thread. Should have some more pics this week
Dave

MARKG
07-30-2011, 10:18 PM
Dave, please post a link to the new thread here too.

Your stuff is major eye candy.

thx

MARKG
08-19-2012, 11:57 PM
http://www.cnczone.com/forums/plasma_edm_other_similar_machine/134470-building_2_5x10_plasma_tables.html

ratfink
12-23-2012, 04:55 AM
I just love the hyperlink to the Chevy Silverado Rack And Pinion Steering Bearings and Seals.... Just makes me feel warm and fuzzy inside... NOT, so fricken tired of total laziness with no quality control over caring about what is linked to or not.... Why? just care... thats it.... why is this so hard to do? either fix these links or dont ever allow them in the first place.... Really?