DIY cnc table plasma cutter

[NRM]

Tom your table is looking very nice and clean. If you don't mind could you shoot some video of your setup and cutting.

[Rodsmachineshop]

thats neat i have a couple of lap tops laying at my shop i don't use . could sacrifice for a cnc table

[acourtjester]

I'll see what I can go on the video it may be a few days.

Rods I was told laptops don't have the power to run Mach 3 but you may check.
I did have a problem with a motherboard that did not have a printer post built in I could not use a add on printer port card.
I bought an older motherboard the used the CPU chip and memory that I had and it all works fine now.
this guy has older cheaper computer parts http://www.pricewatch.com/gallery/mo...ards/pentium_d
Or maybe get one from some one who up-graded their unit.

have fun
Tom

[Rodsmachineshop]

yes my lap tops wont work just buy a bare bone kit there cheap

[acourtjester]

HI All
Well I am done with building and checking out my CNC table.
http://www.youtube.com/watch?v=OJfW0...uRw&playnext=1
Here is a video I did today cutting parts, the short bursts are drill hole marks and the middle of the video was double speed to make is shorter. I'm not sure if all torches are the same but I ran cutting height of .060" at 70 PSI found a formula for water table rust preventer to keep the water clear I have the stuff just need to mix and put in the table.
This table is using a Everlast PM 256 multi-unit plasma with the torch sent with the unit. I was using 55 amps for 1/4" steel plate with no problems. I know the duty cycle would cause a problem for really big parts but for what I am doing it works great. Green Power
Lots of time my everlast and a spair computer and some scrounged materials I think my cost was under $1100.

Have tun
Tom

[acourtjester]

Sorry posted old video here is the new one
http://www.youtube.com/watch?v=WdG9_...1&feature=plcp
Have fun
Tom

[SeanMurphy265]

I think you can go with a USB breakout board you can power it by USB. I know smooth stepper is popular. I thought I could get around buying a desktop, but it looks like I will be ordering an XP refurb from Tiger Direct.....

[Rambozo]

Here is the finger bone I did for the small boc cuts in the video with each command info next to it.
The info is not in the program when it is used


G90F30 G90= absolute distance mode and F30= speed of movements
G28.1Z.5 moves the torch to touch metal top (TOP) in G speak
G92Z0.00 tells Mach 3 to zero "Z" axis
G0Z0.750 moves "Z" to 0.750" above metal
G0Z0.045 moves "Z" to 0.045" above metal
M3 turns on plasmatorch
G4P0.5 delay movement for .5 seconds
G0Z0.035 plunge torch to 0.035"
G0X1.50 move "X" for 1.5"
G0Y1.50 move "Y" for 1.5"
G0X0.00 move "X" back to 0 this is the 3rd side of the cut
G0Y0.00 move "Y: back to 0 this is the 4th side of the cut to close box cut
M5 turns off the plasma torch
G0Z0.750 moves the "Z" back to 0.750" above the metal
M30 end of program and rewind to start position

You could also now move the torch to "X" 2" and then zero "Z" and start cutting

another box like above you could cut a string of boxes by doing this over and

over again.

G0 is a rapid move, G1 is a feedrate move. Depending on your motors, they might be the same, but you should use the correct code. G0 for non cutting moves and G1 for cutting moves. Also it is not a bad idea to make sure the control is in inch mode in the beginning by adding to your first line (G70/71 or some controls G20/21 inch/mm)
For example: G90G70F30

Those, along with a few other G codes are modal and stay in effect until changed, so you can't depend on what setting they are at when your program starts.

[acourtjester]

Good info I will file it for later
Thanks Rambozo

[DaveO]

it looks like I will be ordering an XP refurb from Tiger Direct.....

I've heard that some CNC software works well with XP but not with later operating systems. Microsoft has already stopped supporting XP, though. How much of a problem does that pose for CNC users?

[everlastsupport]

You load XP and the CAD/CAM/CNC software and use it. Keep it off the internet. Should run until hardware breaks on you.

I know MACH3 and BobCAD work fine on Windows 7.

Is the issue talking serial vs USB or the buffering of the I/O that makes XP a better pick?

[acourtjester]

Like Mike said I bet there are many whom have XP on an old computer online just for that reason. I have bought versions of both XP and 7 but continue to use XP and 7 sits in the draw. Aslo the USB controllers seem to expensive now maybe they will come down soon as more companies build them.
have fun
Tom

[Rambozo]

Another option with a support for all kinds of obscure hardware.

http://www.linuxcnc.org

[everlastsupport]

Another option with a support for all kinds of obscure hardware.

http://www.linuxcnc.org

Being an ex-linux and BSD fan. Might have to look at that. Since the price will be better. What do they have for mach3 and a good cad/cam program, I will need something for my mill soon. Linux is fine for me. I will take a look.

[Rambozo]

Being an ex-linux and BSD fan. Might have to look at that. Since the price will be better. What do they have for mach3 and a good cad/cam program, I will need something for my mill soon. Linux is fine for me. I will take a look.

LinuxCNC will replace Mach 3. I'm running an older version from when it was still called EMC2, but from what I see the features are about the same. As with most things open source there are a ton of options as to other software.
Here is a brief list of some CAD and CAM packages from basic scripts for dxf to G code conversions to full blown 3D modeling programs.
http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Cam
And an overview of a few of the more popular ones.
http://www.techdrivein.com/2011/08/8...for-linux.html

I like Draftsight as it's very much like the old AutoCAD R14 for 2D work, and the price is right.
http://www.3ds.com/products/draftsig...e-cad-software

For small things I usually just write the G code by hand from the drawing.

[everlastsupport]

LinuxCNC will replace Mach 3. I'm running an older version from when it was still called EMC2, but from what I see the features are about the same. As with most things open source there are a ton of options as to other software.
Here is a brief list of some CAD and CAM packages from basic scripts for dxf to G code conversions to full blown 3D modeling programs.
http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Cam
And an overview of a few of the more popular ones.
http://www.techdrivein.com/2011/08/8...for-linux.html

I like Draftsight as it's very much like the old AutoCAD R14 for 2D work, and the price is right.
http://www.3ds.com/products/draftsig...e-cad-software

For small things I usually just write the G code by hand from the drawing.

Thanks for the info. I will check it out for sure. Old PCB/Gerber coder hack here, so I think we might like the same things. I have Mach3, pretty but so many lines and you have to buy it. So I figured I would write a program to break the lines up into files and send them over.. The BobCAT I saw a friend use was cool, but they were a tad too eager to sell me and called me over and over when I do not have the plasma table yet and the mill is still at the friends place.

If I go with a 2D for plasma CNC I guess I can just add a Z up and down to make it work?

I liked the old autocads so I will take a look at draftsight. I feel bad for people locked in Windows (and iphones), but this will save me some cash and offer something I can get the source code to as well.

Thanks again RB

[Rambozo]

The 500 line program limit is probably a non issue for most things cut on a plasma table. Especially with the liberal use of do loops, subroutines, and zero shift. But you also lose the torch height control, so that kinda sucks. Most CAM programs write very bloated G code, but it's not that hard to trim the fat, and improve the runtime, while shrinking the code substantially. If you do art stuff, that will be the thing that requires huge programs, just making parts doesn't.

[everlastsupport]

Sounds like I'll be fine then. Milling and plasma only and nothing fancy. I have an old Acad 2004 so maybe I will go the windows route with mach3 and see how it goes.

[acourtjester]

I ran accorss this today for someone who needs a computer for their CNC cheap with XP loaded and on-board printer port.
http://www.compusa.com/applications/...Sku=J001-23016

have fun
\Tom

[SeanMurphy265]

I ran accorss this today for someone who needs a computer for their CNC cheap with XP loaded and on-board printer port.
http://www.compusa.com/applications/...Sku=J001-23016

have fun
\Tom

I'm sure some one out there offers this, but it would be nice to find a setup with computer and controller all together in one ready to run. I picked a pc from walmart.com shipped to my local store pretty cheap with no shipping cost. I found some cheap ones at Tiger Direct as well.