After many months or reading and researching I am finally ready to start building a plasma table. So here are the specs.
48.5"X48.5" travel
water tank
369oz steppers
dual drives on the y
Gecko 201 stepper controllers
20 degree 20 pitch rack and pinion
3.75:1 gear reduction
Hiwin 15mm LG rails on the Y and Z
THK HSR25mm rail on the x
CandCNC Digital THC
Mach 3 control.
Hypertherm 1000

The Table will be made from 3x3x.125 square tube so I started milling the cross pieces for the table square and held .001 on length.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01085.jpg

Then I started drilling and tapping the holes for the 25mm rail for the gantry.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01086.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01087.jpg

Next I started on the Z. The Z is .188 HR plate and 15mm Hiwin rails. It will have 6" of travel. The single rail will be used for the floating head for the torch.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01088.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01089.jpg

Looking good so far. Thanks for taking us along for your build.
DRL

Welcome to the journey. Judging by your having access to a horizontal boring mill. I'd suspect you have access to all the other machine tools, Lathe(s), Milling machine(s), etc to produce a very fine & detailed Plasma table.

Why the small size?

Why the small size?

I was going to build a 4x8 but I just don't have the shop space and I don't really need anything bigger right now. I know I will kick myself later when I need bigger, but I will build another if it comes down to it.

Oh, I am a Manual machinist in a huge machine shop, so I have access to all the cool machines.:)

I sort of figured space must be an issue. Other than that it just doesn't cost that much more to go bigger. You might want to try & leave 1 end of the table bolt together. That way if you later want to expand to 8' or even longer length it can easily be done.

It sucks not to have enough room for at least a 4 X 8. That way sheets od stock are economical & you don't first either have to have them sheared in 1/2 or cut them down yourself first.

Good to have a new build again!!! Fine start too, paint it while building , after done you´ll not want to take it appart ....

Hey Lamicron, Hows your machine running? Sold it yet? Building another?

Hi Rich! Yes I sold it!!! And sold another 2!! Now Im building two 4x8 and one 4x4 for me, and also one router 4x4, i´m waiting to have the material tomorrow. MAybe start a thread with one of those...´One will be a water table for plasma and a router, i ´ll build it with a rapid table change.
Luis

Rich, where did you buy your pulleys? I need 3:1 pack. and belts. Can you help me with part numbers?
Thanks
Luis

Rich, where did you buy your pulleys? I need 3:1 pack. and belts. Can you help me with part numbers?
Thanks
Luis

Luis rather than keeping Bigtoy's thread hijacked. Start a build log in: Plasma, EDM and other similar machine Project Log & pm me the link to it or I'll find as I'm on practically every day. I'll look for the information & get back to you there later.

Neil

Sorry for that, you are rigth.
Luis

I got a little bit more done today. I got the Y rail holes drilled and tapped, then I welded the frame all together. I still need to weld a sheet on the bottom to form the water tank.

http://i122.photobucket.com/albums/o269/bigtoy302/DSC01093.jpg

the welds
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01092.jpg

holes for the rails.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01094.jpg

Bigtoy,
I recently came across this site. WOW! I have wanted, but could not justify a toy this expensive for a couple years. The prospect of making a plasma table myself has consumed my spare time. Like you, I am reading everything I can find on the subject. I am working out the details now. I plan on starting the build by early summer ('08). I look forward to your updates. I am a fairly accomplished welder myself and I would like to say your welds are impeccable. It looks like we are neighbors too, as I live in southern Oregon.
---Bob

Beautiful welds

Bigtoy,
I recently came across this site. WOW! I have wanted, but could not justify a toy this expensive for a couple years. The prospect of making a plasma table myself has consumed my spare time. Like you, I am reading everything I can find on the subject. I am working out the details now. I plan on starting the build by early summer ('08). I look forward to your updates. I am a fairly accomplished welder myself and I would like to say your welds are impeccable. It looks like we are neighbors too, as I live in southern Oregon.
---Bob

The fun really begins when you start a build.

I was a total greenhorn when I began. I made up some CAD drawings mainly to keep some of my ideas straight. I was lost for quite some time. I really wanted to have most all my parts gathered up before I started.

There are so many things that depends on the part next to it. What do I need to buy so I don't build myself into a corner? Is this heavy enough, Is that strong enough? If I buy this rack & pinion, What belt reduction ratio do I need. Darn I actually would like to have my motors in hand so I can build the drives as small as practical yet rugged & strong.

All these things & trying to think things through to the end took many hours of head scratching & decision making. The time thinking paid off though in not having to un-do progress already made.

Looking back I could easily build a second table. Mine has worked out great so far. If I were to start over there is a few things I'd do different but not many.

I made some caps for the legs so I could screw so adjustable roller feet in them.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01096.jpg

Then I got the bottom of the table sealed off with a piece of 16 gauge. I welded
small beads all the way around and let each one cool to try and reduce warping.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01097.jpg

Here are my gantry side plates all cut out.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01095.jpg

I then started working on the Z axis acme screw. The bearing blocks where machined for a 608 bearing. The acme screw is a 1/2-10 single single start screw. The nut is a delrin nut from Dumpster CNC.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01099.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01100.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01098.jpg

Today I had to straighten the table. It had warped about .125 all the way around in the center of the tubes. I did the old heat and quench trick to shrink the top back down. This method worked really good.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01101.jpg

Then I mounted the rails and welded the gantry tube to the side plates.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01103.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01102.jpg

Now after I had the gantry all welded together I totally understand what racking is. I am sure glad I didn't cheap out and not buy a extra motor to dual drive the Y.

Today I had to straighten the table. It had warped about .125 all the way around in the center of the tubes. I did the old heat and quench trick to shrink the top back down. This method worked really good.
Now after I had the gantry all welded together I totally understand what racking is. I am sure glad I didn't cheap out and not buy a extra motor to dual drive the Y.

Have no fear the dual slaved drive will completely eliminate the racking. Mine seemed limp as a noodle. everyone that saw it said it would never work. When you get everything hooked up & power on the motors you'll be amazed how solid it becomes.

Neil

So, today I got the belt drives, racks and the Z mounted. I Also tested the water tank to make sure I had no leaks. I added some tubes on the bottoms of the legs for more support. With nothing there the table was just to shaky. I still have some finish weld and I still need to make the slat holders, but other wiring and paint it's almost done.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01104.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01105.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01106.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01107.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01108.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01109.jpg

Bigtoy,
I don't understand your Z axis. It appears to have 2 slide systems and only one of them is powered. Does the other float? Will it eventually be powered? Your table looks great! One last question, do you know how much the gantry assembly weighs?
Thanks,
Bob

Bigtoy,
I don't understand your Z axis. It appears to have 2 slide systems and only one of them is powered. Does the other float? Will it eventually be powered? Your table looks great! One last question, do you know how much the gantry assembly weighs?
Thanks,
Bob

Bob, The single rail is for the floating head. I have not weighed the gantry yet.

So, today I made the slat holders and put them in. I used 3/8 round welded to the sides to hold the slats and I cut the slats a little long so they would bow a bit. I then made all the mounts to hold the cable carriers on.

http://i122.photobucket.com/albums/o269/bigtoy302/DSC01121.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01122.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01123.jpg

A couple of suggestions......
Is it a good idea to have the slats going right down to the bottom of the tank?
My tank has the slats sitting off of the bottom by about an inch.
Also having each slat sectioned off won't allow the water to circulate, and in well used sections won't the water get contaminated very quickly???

Are you going to 'sawtooth' the tops of the slats?
I think just having the flat edges you may get problems with the parts 'welding' themselves to the slat edge???
I have my slats 'sawtoothed on both sides, and I can turn over when they get too worn out.

How are you running the dual motors?
I am toying with the idea of building a Mark 2 Plasma machine. I need to be able to cut a 2000mm (80") x 1000mm (40") Stock sheet.
I think I will need to use dual motors on the X Axis, so do you hardwire them or setup separate motor setups in mach and drive them together???

Andy

I think I will need to use dual motors on the X Axis, so do you hardwire them or setup separate motor setups in mach and drive them together???

Andy

Andy, you use (2) motors & (2) drivers, wired seperately just as if it were a complete seperate axis. Then in Mach, motor slaving, slave the second axis (usually A) to X. other than having them tuned exactly the same & making sure the rotation is correct. That's all there is to a dual drive.

Wow you are further along than me..

So is it really a benefit to run a water table?

Also, what kind of linear guide is that for the X axis?

Also, why did you go steel material on the gantry? Do you think all that mass will slow the machine down?

A couple of suggestions......
Is it a good idea to have the slats going right down to the bottom of the tank?
My tank has the slats sitting off of the bottom by about an inch.
Also having each slat sectioned off won't allow the water to circulate, and in well used sections won't the water get contaminated very quickly???

Are you going to 'sawtooth' the tops of the slats?
I think just having the flat edges you may get problems with the parts 'welding' themselves to the slat edge???
I have my slats 'sawtoothed on both sides, and I can turn over when they get too worn out.

How are you running the dual motors?
I am toying with the idea of building a Mark 2 Plasma machine. I need to be able to cut a 2000mm (80") x 1000mm (40") Stock sheet.
I think I will need to use dual motors on the X Axis, so do you hardwire them or setup separate motor setups in mach and drive them together???

Andy

The slats do touch the bottom but when you put the water in the bottom of the tank bows a little bit under the slats so there is a little bit of room for cirulation. I am leaving the slats flat. I think most setups use flat slats so I don't think it's going to be a problem.

Bigtoy302, Great looking job Keep up the great work & you'll be making the sparks fly in notime.

Neil

I did not get a whole lot done this weekend but I did get it put back together and started the wiring.

http://i122.photobucket.com/albums/o269/bigtoy302/DSC01128.jpg

Switch installed for the floating head.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01129.jpg

This weekend I got the control cabinet all wired up. I still have to mount a few home switches but thats it. I used some 60mm amd heatsinks and fans for the geckos. I then mounted them to the back of the box.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01137.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01138.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01139.jpg

Real professional job! What other components are needed in the box, and what did you choose? The Geckos are obvious but I don't know enough about them to recognize the others. Thanks for this build thread keep the updates coming!!
Dick

Do you have other hole(s) in the box to let cooling air in/out? Are you going to filter the cooling air in some manner?

Nice looking job on your control box. Since it's metal are you going to insulate it from the table to help keep ground noise down?

Do you have other hole(s) in the box to let cooling air in/out? Are you going to filter the cooling air in some manner?

Nice looking job on your control box. Since it's metal are you going to insulate it from the table to help keep ground noise down?

There is a good size hole in the botom of the box. I dont have any plans on filters. I will insulate the box if noise becomes a issue.

Impressive build; thanks for documenting it. Makes it look easy!

I'm just starting research, sorry if this is an obvious question - can you/someone help me understand what the concept behind the floating head mechanism is and how it works in conjuction with the Z axis? (I've never seen a water table up close in action, so that may be why I can't picture what it's for)

Thanks-
ed

Impressive build; thanks for documenting it. Makes it look easy!

I'm just starting research, sorry if this is an obvious question - can you/someone help me understand what the concept behind the floating head mechanism is and how it works in conjuction with the Z axis? (I've never seen a water table up close in action, so that may be why I can't picture what it's for)

Thanks-
ed
The floating head is for automatically finding the top of the metal. You tell mach how far it travels before it trips the switch then it automatically goes down until the switch is tripped then goes up the specified amount + peirce hieght and starts the cut.

Thanks for the explanation, bigtoy. Your description, along w/ your pic in post #29 makes sense. After the limit switch is tripped, is there some sort of holding mechanism (e.g. electromechanical clamp) that freezes the slide in that position so when the Z axis is raised, the torch raises with it? Put another way, what keeps the torch head from staying rested on the metal, while the Z axis raises and lowers?

thanks-
ed

It looks great! What is the current status?
I am looking a a build, and am interested in your project.

It looks great! What is the current status?
I am looking a a build, and am interested in your project.

I have been pretty busy doing other stuff lately so I have not worked on it in a few months but I will try to finish it in the next couple weeks.

So today I got some more time to work on the table. After many hours of trying to get the second parallel port card installed I finally got it. I got it all hooked up and spun the motors for the first time. Hopefully this weekend I can cut some metal.

Good luck, well built machine.

Good progress please keep us posted.

So after many more hours of frustration with the parallel port card not working properly I reinstalled the drivers and everything started working like is supposed to. I Filled the table up with Plasma Quench and cut a test piece. Everything worked good.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01144.jpg
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01141.jpg

I cut this piece from 16 gauge at 40 amps and 120IPM.
http://i122.photobucket.com/albums/o269/bigtoy302/DSC01142.jpg

Here is a video of the part being cut.
http://i122.photobucket.com/albums/o269/bigtoy302/th_MOV01147.jpg (http://s122.photobucket.com/albums/o269/bigtoy302/?action=view&current=MOV01147.flv)

Congratulations on completing your excellent build & making those first cuts!:)

The nice clear photos & video are sure to inspire others. Thanks for sharing.

Bigtoy302,

Congratulations. You've built a very nice machine. What kind of rapids are you getting? It looks like it flies!!!

Bigtoy302,

Congratulations. You've built a very nice machine. What kind of rapids are you getting? It looks like it flies!!!

I have the rapids set at 450 IPM.

Nice job of building and documenting. Where can you find and buy straight plasma cutting wands? The Torchmate has a straight cutter. I also need to re-read and figure out the purpose and construction of the floating head.

Thanks for sharing.

Nice job of building and documenting. Where can you find and buy straight plasma cutting wands? The Torchmate has a straight cutter. I also need to re-read and figure out the purpose and construction of the floating head.

Thanks for sharing.

Straight plasma "wand" (machine torch) can be purchased from your plasma machine dealer (Hypretherm, Thermal Dynamics) etc. Many listed on Ebay.

The purpose for using a floating head, is to allow your "Z" axis to come down & touch your torch head to the surface of the material being cut. When properly adjusted the torch touches, activates a micro switch telling your software Z axis "0.00" has been achieved. Your software will then retract your cutting tip to the desired height "cut height" above the metal before activating the plasma cutter.

The picture below is the property of www.CandCNC.com and is a very good example of a floating head.

Millman,
Is it possible to have only Z-axis, not have floating head axis? I don't clear.

Mongkol

Millman,
Is it possible to have only Z-axis, not have floating head axis? I don't clear.

Mongkol

Yes, you can eliminate the floating head but you will loose your touch-n-go feature.

Ok, I sort of get the idea but, once you touch the torch to the material and it triggers the zero mark, when you back off what keeps the torch from falling back towards the surface and leaving you with that amount of movement where you now have a zero setting but the torch is actually lower?

Can you take some photos of your set up and post them? Also the wire schematic of how it's all wired up? This is very interesting and you did a fine job on your machine.

Ok, I sort of get the idea but, once you touch the torch to the material and it triggers the zero mark, when you back off what keeps the torch from falling back towards the surface and leaving you with that amount of movement where you now have a zero setting but the torch is actually lower?

Can you take some photos of your set up and post them? Also the wire schematic of how it's all wired up? This is very interesting and you did a fine job on your machine.

I am running Ox/Fuel so no floating head. Here is my understanding of how it works. Please anyone else correct my errors if I'm wrong here.

For NON VOLT SENSING ot constant height setting: Once the Z axis drops, touches the metal & triggers the limit swith you need a stop to limit the downward (floating) motion. That will remain a constant. You then have to do some measuring & some math.

Example: if your torch touches & continues to travel downward .125" till it trips the limit switch ( this you will somehow need to measure accurately)& is also the floating part of the mechanism. Lets say you need to use a .010 TH above your metal. This means you must set your software to lift .135 from the point it trips the limit switch.

I just picked these #'s for an example & are NOT A GUIDE! Just trying to help clear it up for you.

When using a Digital voltage sensing THC The same thing happens, touch off, trip switch, raise a pre determined height above metal, plasma torch fires & pierces & the Digital THC takes over & lifts or lowers the Z axis to maintain optimum cutting height even as the metal warps & bows.

Like I stated earlier I have never actually set one up. Please someone, anyone correct me if I'm wrong.

I am running Ox/Fuel so no floating head. Here is my understanding of how it works. Please anyone else correct my errors if I'm wrong here.

For NON VOLT SENSING ot constant height setting: Once the Z axis drops, touches the metal & triggers the limit swith you need a stop to limit the downward (floating) motion. That will remain a constant. You then have to do some measuring & some math.

Example: if your torch touches & continues to travel downward .125" till it trips the limit switch ( this you will somehow need to measure accurately)& is also the floating part of the mechanism. Lets say you need to use a .010 TH above your metal. This means you must set your software to lift .135 from the point it trips the limit switch.

I just picked these #'s for an example & are NOT A GUIDE! Just trying to help clear it up for you.

When using a Digital voltage sensing THC The same thing happens, touch off, trip switch, raise a pre determined height above metal, plasma torch fires & pierces & the Digital THC takes over & lifts or lowers the Z axis to maintain optimum cutting height even as the metal warps & bows.

Like I stated earlier I have never actually set one up. Please someone, anyone correct me if I'm wrong.

Thanks for the reply. Seems to me there should be a easier way. LOL Maybe I'll ask over on the MACH 3 forum and see what some of those folks have to say as well. I think there is a way they do a tool/bit touch pad thing that shold work about the same.

Hi All,
If I have THC system,Is it necessary to have the floating head? Pls advise.
Mongkol

I'm thinking that a touch pad thing where when the torch nozzle touches it zeros the "Z" axis then MACH 3 would back off to the punch and then move to the cutting height.

For some reason that sounds logical to me. :confused:

I'm thinking that a touch pad thing where when the torch nozzle touches it zeros the "Z" axis then MACH 3 would back off to the punch and then move to the cutting height.

For some reason that sounds logical to me. :confused:

The floating head works the best on thin metal that warps easily. Thin stuff can warp over .250". If you didn't have a floating head on something that moved up a .250", the torch would crash into the piece the next time tried to pierce.

The floating head works the best on thin metal that warps easily. Thin stuff can warp over .250". If you didn't have a floating head on something that moved up a .250", the torch would crash into the piece the next time tried to pierce.

Even if you used the touch pad every time between materials? Do you have one of these floating heads? I'd like to get a better idea of how they work and how your's is set up.

Even if you used the touch pad every time between materials? Do you have one of these floating heads? I'd like to get a better idea of how they work and how your's is set up.


That would not work. Your touch pad is not going to warp with the metal. There are pictures in this thread of my floating head. Watch my video of the head in action. They are not that hard to make. Your over complicating things with the touch pad.

That would not work. Your touch pad is not going to warp with the metal. There are pictures in this thread of my floating head. Watch my video of the head in action. They are not that hard to make. Your over complicating things with the touch pad.

I agree Bigtoy. The floating head is a pretty simple mechanism. Both in concept & it's function.

I haven't been on the board in a while. Want to congratulate you on a good job. Looks like you are off and running. If you are like most everyone else who builds a table, I expect there are a few tweaks you intend to make?

I have had my Ox/Fuel table going now since Jan. It still amazes me just what all I can get done with it. I have already recovered my cost & totally in green ink with it's use. I wish I had built one a few years ago when I first learned it was possible to use a PC for control.

I expect there are a few tweaks you intend to make?



The only thing I am going to change is I need to move the switch for the floating head to a higher location. It gets splashed with water then arcs out.

The only thing I am going to change is I need to move the switch for the floating head to a higher location. It gets splashed with water then arcs out.

I noticed that in your pictures & wondered why you hadn't mounted it up where the very top edge of the short piece of liner rail would activate it.

This would allow the floating head to move freely without it's upward travel being limited by the switch itself. As well as be out of the heat & water.

That would not work. Your touch pad is not going to warp with the metal. There are pictures in this thread of my floating head. Watch my video of the head in action. They are not that hard to make. Your over complicating things with the touch pad.

Thanks Bigtoy, I'll go back and review your configuration. I'm a little thick when it comes to this CNC stuff as I am very new to the hobby and getting older and it's harder for me to learn. :)

After many months or reading and researching I am finally ready to start building a plasma table. So here are the specs.
48.5"X48.5" travel
water tank
369oz steppers
dual drives on the y
Gecko 201 stepper controllers
20 degree 20 pitch rack and pinion
3.75:1 gear reduction
Hiwin 15mm LG rails on the Y and Z
THK HSR25mm rail on the x
CandCNC Digital THC
Mach 3 control.
Hypertherm 1000


First off, very nice job on your plasma cutter. Looks great...

I'd like to know how much roughly the above components cost you, as well as a rough price of the steel to build your table?

Jesse

First off, very nice job on your plasma cutter. Looks great...

I'd like to know how much roughly the above components cost you, as well as a rough price of the steel to build your table?

Jesse

I think I have about $5500 in to it total. Steel was about $250.

$5500 for the components listed above or total including everything (PC, plasma cutter, etc)?

$5500 for the components listed above or total including everything (PC, plasma cutter, etc)?

Yes, everything.

Bigtoy,

Saw this build over on Pirate also, seems like this one is more detailed.



Couple questions.

-What powersource are you using?

-Maybe i missed this but how are you keeping your floating head from "falling" out of the rail (thought i saw a set screw somewhere but i wasnt sure)?

-Is your 15mm rail on your X axis stout enough to keep your head from "rotating" and causing the X axis to bind?

-Are all your wires for your switches and drives shielded or does that not really matter?


Your project is awesome and it is inspiring me to do some work.


EDIT: Are you using a home switch on both your Y and slave A axes?

Bigtoy,


-What powersource are you using?


I am using a toroidal transformer from Antek and a cap and bridge from Digikey.



-Maybe i missed this but how are you keeping your floating head from "falling" out of the rail (thought i saw a set screw somewhere but i wasnt sure)?

There is a piece weld to the bottom of the Z to catch the rail. If you look closely you can see it in the pics.


-Is your 15mm rail on your X axis stout enough to keep your head from "rotating" and causing the X axis to bind?

The x rail is a 25mm with two block so no flexing or binding.


-Are all your wires for your switches and drives shielded or does that not really matter?

All the wires are unshielded. everything works fine that way.


EDIT: Are you using a home switch on both your Y and slave A axes?

I have not got around to actually mounting the switches. All the wires are there but I have too lazy to hook them up.

I really appreciate your posting the details of your build.

I have a question, if you don't mind. What are the dimensions
(inside of the rails) for the length and width of your table?

Thanks,

Mike Allen

Awesome build. You made it look so easy, and professional.
Thanks for taking time to show us the details.

One question for the group; why the fluid in the bed? Just for better electrical connection?

Awesome build. You made it look so easy, and professional.
Thanks for taking time to show us the details.

One question for the group; why the fluid in the bed? Just for better electrical connection?

To keep all the dust and smoke down.

Hi Bigtoy,
I am building plasma table by rack-pinion concept. I am interested in your method. Pls take a look from picture. I am puzzled with motor-plate which is held with one screw and one spring. I have some question.
1) This concept, Is it enough to support the weigth of motor and aluminium plate set?

Hope your help
Mongkol

Mongkol this looks very close to the design I used for my table. The bolt I used was a 1/2" diameter and I can not imagine that not being strong enough. Looks good to me.

Hi Bigtoy,
I am building plasma table by rack-pinion concept. I am interested in your method. Pls take a look from picture. I am puzzled with motor-plate which is held with one screw and one spring. I have some question.
1) This concept, Is it enough to support the weigth of motor and aluminium plate set?

Hope your help
Mongkol

The 1/2" bolt is plenty strong enough to hold the drives. They weight less then 10lbs. The spring is on the light side. If I put all of my weight (180lbs) on the gantry at 450ipm I can get the drives to skip on the rack. But during normal cutting the machine dose not see any cutting forces.

Bigtoy,
Thanks for your reply. I also found the floating head on Z-axis. I have another question.
1)I see it has limit switch on Z-axis for the floating head.How to hook up limit switch on it ? I have not ever seen the circuit of the limit switch of the floating head. ( Link to Z++ or Z,home) Pls advise.
2)If I have the torch heigh control system,is it necessary to have the floating head on Z-axis?

Happy new year
Mongkol

Bigtoy,
Thanks for your reply. I also found the floating head on Z-axis. I have another question.
1)I see it has limit switch on Z-axis for the floating head.How to hook up limit switch on it ? I have not ever seen the circuit of the limit switch of the floating head. ( Link to Z++ or Z,home) Pls advise.
2)If I have the torch heigh control system,is it necessary to have the floating head on Z-axis?

Happy new year
Mongkol

The switch hooks up to Z home. It is necessary to have a floating head on the THC so you always know were the top of the metal is.

Using a floating head design you can swap different thickness of sheets you lay on the table and the machine still finds and compensates for the different thickness. Example: you are cutting 14 ga. material and need to cut 3/8 next. Just change plates and the floating head will find the top of the material by lowering the tip until a limit switch is tripped. The torch then will rise just enough to clear the switch. This height is Z home. Just another way of making life simpler for operators.
I was really having a hard time getting this floating head design driven into my little brain until I talked w/ Torchead about it one day. Made perfect sense to me then.

Hi Plain of bill and Big toy,
If I use THC and the floating head,I have three questions.
1)It looks like the circuit of micro-switch don't complicate. Is it correct?
2)If I cut steel plate at thickness 6 mm, how to set pierce height ,pierce delay,cut height and so on? Could you guide me?
3) The torch should touch on the top of material before operation or not.


Sorry if I disturb you
Mongkol

Hi Plain of bill and Big toy,
If I use THC and the floating head,I have three questions.
1)It looks like the circuit of micro-switch don't complicate. Is it correct?
2)If I cut steel plate at thickness 6 mm, how to set pierce height ,pierce delay,cut height and so on? Could you guide me?
3) The torch should touch on the top of material before operation or not.


Sorry if I disturb you
Mongkol

The floating head circuit is not complicated. It is just a z home switch. Pierce height, delay, and cut height are set by your cam program. I use sheetcam and you set all the parameters in there. In your post it will tell it to find the top of the metal before every pierce of not.

where could i buy some plans for a table like this?

In your post it will tell it to find the top of the metal before every pierce of not.

Bigtoy,
I have to set up the torch to X,Y,Z=0.000 on the top of material surface before run machine. Is it correct ?

Thanks so much for your patience and help
Mongkol

Bigtoy and Friend,
I found some problems.
I have the limit switch of floating head on Z-axis. It links to pin13 and port1,Z-home.I use active high and NC connection.I toggle the THC ON to ON in mach3 screen and then click on the cycle start. the X and Y move to the first pierce point.The Z-axis move down by a little and torch fire immediately. Sounds like it ignores G28.1 Z3.00 to move Z down to hit the material and not hit the limit switch.of the floating head
What is the rootcause for jumping from G28.1 z3.00 line to M03 line? ( not work on G28.1 z3.00 line)


Mongkol

Bigtoy and Friend,
I found some problems.
I have the limit switch of floating head on Z-axis. It links to pin13 and port1,Z-home.I use active high and NC connection.I toggle the THC ON to ON in mach3 screen and then click on the cycle start. the X and Y move to the first pierce point.The Z-axis move down by a little and torch fire immediately. Sounds like it ignores G28.1 Z3.00 to move Z down to hit the material and not hit the limit switch.of the floating head
What is the rootcause for jumping from G28.1 z3.00 line to M03 line? ( not work on G28.1 z3.00 line)


Mongkol

Post up what your program actually looks like.

Bigtoy,
I use sheetcam and here's my g-code.
Mongkol

I use the switch offset= -6.612 mm
***************************************
N0000 (Filename: test8.tap)
N0010 (Post processor: Plasma THC300.post)
N0020 (Date: 9/17/2006)
N0030 G21 (Units: Metric)
N0040 G53 G90 G40
N0050 F1
N0060 S500
N0070 (Part: circle)
N0080 (Process: Set variable switch offset = -6.612 )
N0090 (Process: Plasma, IN, Plasma, 1 mm kerf)
N0100 M06 T1 (Plasma, 1 mm kerf)
N0110 G00 Z0.0000
N0120 X25.0000 Y42.1490
N0130 G28.1 Z3.00
N0140 G92 Z0.0
N0150 G00
N0160 G92 Z0.0
N0170 G00 Z2.0000
N0180 M03
N0190 G04 P0.1
N0200 G01 X25.0000 Y42.1490 Z1.0000 F500
N0210 G03 X25.0000 Y42.1490 I0.0000 J-3.5000 F1000.0
N0220 M05
N0230 G00 Y13.0038
N0240 Z2.0000
N0250 M03
N0260 G04 P0.1
N0270 G03 X25.0000 Y13.0038 Z1.0000 I0.0000 J-3.5000
N0280 (Process: Plasma, OUT, Plasma, 1 mm kerf)
N0290 M05
N0300 G00 X25.0000 Y-0.5000
N0310 Z2.0000
N0320 M03
N0330 G04 P0.1
N0340 G03 X25.0000 Y-0.5000 Z1.0000 I-0.0000 J25.5000
N0350 M05
N0360 M05 M30

Hi Bigtoy,
I can clear the problem of micro switch on the floating head already. It work fine by now.
I have some questions.
If you cut the circle, the external circle and internal circle is round or not.
I found some problems. The external circle is good but the internal circle is bad after cutting. It is not round and has the slack. I am not sure what is the problem.
It may be the torch is not perpenticular with meterial. Your machine is OK or not if you cut the circle. Is it round?


Mongkol

So the other day I sold my Hypertherm 1000 and bought the new Hypertherm powermax45. OMG this thing is awesome. It puts my 1000 to shame on cut quality. I can actually cut holes that are round and put a bolt through without drilling. A 3/8" hole in 1/4" only needs to be cut .015 over sized to get a bolt through it. At only 45 amps it still cuts 1/4" and 3/8" steel way better then the 1000. If anybody is thinking of buying a new plasma this is it. I have only cut about 15 parts so far so I don't know about consumable life yet but Hypertherm claims up to 3 hours of cut time on one set of consumables.

Here is a piece of 1/4" with a 3/8" hole cut at 50ipm. The hole was cut at 25ipm.
http://i122.photobucket.com/albums/o269/bigtoy302/IMG_0201.jpg

Here is a piece of 3/8" AR500 cut at 30ipm. Almost laser quality.
http://i122.photobucket.com/albums/o269/bigtoy302/IMG_0203.jpg

This thing is tiny compared to the 1000.
http://i122.photobucket.com/albums/o269/bigtoy302/IMG_0204.jpg

After cutting, the edge of steel is very beautiful and the hole is round.
If you change to cut stainless steel, Is it O.K.?


Mongkol

After cutting, the edge of steel is very beautiful and the hole is round.
If you change to cut stainless steel, Is it O.K.?


Mongkol

I have not had a chance yet to cut stainless.

Very nice. A couple quick questions. Could you give me some approximate dimensions of your gantry side plates? I was going to design mine differently but really like how yours came out.

For your rack & pinion and gear reduction parts, where did you get the parts and what ratios did you use?

I am working on a very similar build.

Thanks,
Brian

I finally got a chance today to actually read all the post and look at all the photos. Your build was very professional and had superb craftsmanship. Thank You for your pics/post and wish you good luck in the cnc world. After cutting a few parts is everything working good? Do you have any problems or things you would change? Where did you buy your plastic cable chain or part # ? Thanks, Dustin

I finally got a chance today to actually read all the post and look at all the photos. Your build was very professional and had superb craftsmanship. Thank You for your pics/post and wish you good luck in the cnc world. After cutting a few parts is everything working good? Do you have any problems or things you would change? Where did you buy your plastic cable chain or part # ? Thanks, Dustin

Everything is working good. The only thing I would change is make it 5x10. My next table will be 5x10. Cutting sheets in half is a pain and sheets selections is better and cheaper for 5x10. The cable carriers came from Mcmaster carr.

Very nice. Do you have blueprints (dxf or so)

http://www.plasma777.com

Very nice. Do you have blueprints (dxf or so)

http://www.plasma777.com

No I do not.

Nice table, I recognize your pictures from Pirate.

How do you do holes like that? I thought you have to do edge starts. I haven't finished my CNC table yet, but when I'm cutting by hand, if I ever start in the middle of the panel, I have molten metal shoot back at me and mess up my torch's head. Well I get that problem for anything over 1/8" at least. Also, do you mean a 5x10' table to fit 4x8' sheets on or making a.. say 5.5x11' table to hold 5x10' sheets? I haven't bought large piece of sheet metal yet, but I thought the average size is 4x8'. If the sheets are really 5x10' I'm going to have to completely redesign my table damn lol.

Anyways, thanks for posting your build up, was a cool read.

4x8 is most common size to purchase for sheet metal but 5x10 is very common sheet.. and for table size it all depends on the travels of the bearing..

for my big cnc table the table is actually 7 foot 6 inch by 12 foot but the travels of the bearing is only 5 foot n 6 inch by 10 foot n 6 inch

Nice table, I recognize your pictures from Pirate.

How do you do holes like that? I thought you have to do edge starts. I haven't finished my CNC table yet, but when I'm cutting by hand, if I ever start in the middle of the panel, I have molten metal shoot back at me and mess up my torch's head. Well I get that problem for anything over 1/8" at least. Also, do you mean a 5x10' table to fit 4x8' sheets on or making a.. say 5.5x11' table to hold 5x10' sheets? I haven't bought large piece of sheet metal yet, but I thought the average size is 4x8'. If the sheets are really 5x10' I'm going to have to completely redesign my table damn lol.

Anyways, thanks for posting your build up, was a cool read.

With CNC cutting you pierce around 2x as high as your cut hieght to prevent molten metal from blowing back into the torch. On my Powermax45 I pierce 1/4" at .150 height.

On the sheet size the table would be a little bigger then the sheet you are cutting. So for 5x10 you would make the cutting area a little bigger then the plate. My next table will be a 5x10 so it will actually have about 61"x121" of travlel. 4x8 is the most common size but 5x10, 4x10, 4x12 and 5x12 is also really common around my area. I hate buying a big sheet and cutting it down to 4x4.

With CNC cutting you pierce around 2x as high as your cut hieght to prevent molten metal from blowing back into the torch. On my Powermax45 I pierce 1/4" at .150 height.

On the sheet size the table would be a little bigger then the sheet you are cutting. So for 5x10 you would make the cutting area a little bigger then the plate. My next table will be a 5x10 so it will actually have about 61"x121" of travlel. 4x8 is the most common size but 5x10, 4x10, 4x12 and 5x12 is also really common around my area. I hate buying a big sheet and cutting it down to 4x4.

I built my table 61 X 121 Apx. Hadn't been running anytime till I needed 5' X 12' Wish I had gone with that to start with.