Home Built CNC Plasma Table

[LScout800]

Decided to put a thread together to maybe help anyone else who wants to do this. I built a plasma table with a bunch of cheap amazon belts and pullies, skateboard bearings, and a bunch of little 3D printed parts and scrap metal.

The table itself cost me like 40 bucks to build, so it was more of an experiment to tell me exactly what I wanted in a table. I them came up with a new design. Here is the Solid Works model.

Some of the specs:

• 30x32 stainless steel water pan for a dryer
• NEMA 23 steppers
• 2020 aluminum extrude v channel frame
• 3D printed parts all over
• Arduino running GBRL controlled by OpenBuildsCONTROL
• LTP5500D Lotus Plasma Cutter
• Proper bearings
• Belt drives

Hopefully will be quite a bit better than the other one. I had the scrap laying around, but those 3D printer belts don't last long hauling around all that weight...

Some links that are useful:

Home

An open source, embedded, high performance g-code-parser and CNC milling controller written in optimized C that will run on a straight Arduino - gnea/grbl

github.com

This one is great for the very basics behind CNC


Should have all the parts in/printed tomorrow, so hopefully it will get built.

 

[SomeGuyFromOlympia]

I source my belts off of McMaster Carr

Pretty sure they are OEM Torchmate, and I have a set that have been going for 10+ years now

 

[Bacho]

I am looking forward to this thread.

My machine uses kevlar belts. I am less than thrilled with its performance so far.

 

[LScout800]

I source my belts off of McMaster Carr

Pretty sure they are OEM Torchmate, and I have a set that have been going for 10+ years now

I am looking forward to this thread.

My machine uses kevlar belts. I am less than thrilled with its performance so far.

I don't think the belts themselves were an issue, it was mainly the aluminum drive pullies stripping because of the weight. I ordered some slightly bigger belts, and this one will be quite a bit lighter to. If not I will bite the bullet and drop the 200 bucks on some lead screws.

 

[PAToyota]

I just watched this video the other week - he uses an inexpensive laser table:


It proves there are options to get set up with CNC plasma fairly inexpensively. Obviously, it's not a production machine, but it could get certain people up and running.

 

[LScout800]

Went ahead and built the table since I had all the parts in. Was pretty cool to just follow solidworks drawings to cut parts to length and have it go together perfect rather than design as you build. Only took me 4 hours.

Making some cuts into some 16 gauge I had laying around. No water in the pan yet.

Cut out one of these lion templates after getting the machine dialed in.

Am pretty happy with it. Going to draft up a stand and a little box to store the electronics in. I also put together a quick excel sheet with everything I had into the table, minus the laptop and air compressor.

Item	Cost ($)	Total ($)
Water Pan	125.45​	1117.66​
2020 Extrude Connectors (2x)	41.88​
Gantry Bearings (3x)	35.97​
2020 Aluminum Extrude 48"	100.73​
Wiring	17.51​
Arduino UNO	31.21​
NEMA 23 Steppers (2x)	59.14​
Aviation Connector Plugs	9.84​
Torch On/Off Relay	6.01​
Arduino Wires	7.64​
5mm Rods	6.56​
Belt	18.99​
Idler Pullies	8.99​
Drive Pullies	7.99​
DM542 Stepper Drivers (2x)	41.76​
24 Volt Power Supply	26.99​
USB Cable	6.64​
Lotus LTP5500DCNC	546.41​
3D Printer Filament	17.95​

Probably going to be just under $1300 when I am done. Not bad considering Lang mire has comparable tables for about $1500 without the plasma cutter, and this one has a bigger cutting area and a water pan. Hoping to get it totally dialed in, have wanted one since I discovered thy exist and it will really increase productivity and quality of the work I do.

Some more questions:

• Does anyone have a reference guide for setting up things like amperage, air pressure, and feed speed? There is a lot of random carts out there but I was wondering if anyone had a good guide.
• How do you set the torch height manually? I was probably going to 3D print a little gauge to set the torch height to roughly a millimeter above the material. I will probably make a z-axis for it eventually.
• What are people running in the water tables? I have heard of people running a mix of water and antifreeze to prevent rust, but there is probably a better alternative to this. I don't want to run straight water and have all the slats rust together so I can't take them out to replace them.

 

[Bacho]

Hypertherm manuals have cutting guides in them for desired speed and amperage.

I would advise you go ahead incorporate a THC system in now.

 

[PAToyota]

Hypertherm manuals have cutting guides in them for desired speed and amperage.

This:

As you can see, the torch height stays consistent during cutting. The issue is that you want to pierce further away when there is blowback from the pierce. Also, the THC helps with things like warpage during cutting and lifting the torch out of the way for travel so that it doesn't hit tip-ups.

What are people running in the water tables?

Something like this: https://www.trick-tools.com/PICO-G-Quench-Guard-G-Anti-Corrosive-Additive-for-Plasma-Tables-14578

PICO Quench Guard G anti-corrosive and coolant additive is a must for any CNC plasma or waterjet cutting table. It is specifically designed to minimize rust, control odor, and reduce bacteria growth. The Quench Guard G is a green transparent, non-foaming coolant that leaves a protective film and has no adverse effects on welding. 1 gallon of Quench Guard G treats 10-20 gallons of water.


Quench Guard G is also designed to neutralize accumulated hydrogen in a baffled water table system. This process allows for cutting aluminum on a water table system without additional safety requirements. Proper concentration levels must be maintained when cutting aluminum.

 

[LScout800]

I had made a moveable Z-axis and tried making up a THC for the other machine I made, but was having issues with the limot switches (machine would randomly trigger the switch cause the computer to freak out.) Plus the THC was being a pain. Planning to try it again but just needed the machine now since I had a bunch of parts I needed to cut with it, hence why I left out the Z-axis for now.

 

[SomeGuyFromOlympia]

Some more questions:

• Does anyone have a reference guide for setting up things like amperage, air pressure, and feed speed? There is a lot of random carts out there but I was wondering if anyone had a good guide.
• How do you set the torch height manually? I was probably going to 3D print a little gauge to set the torch height to roughly a millimeter above the material. I will probably make a z-axis for it eventually.
• What are people running in the water tables? I have heard of people running a mix of water and antifreeze to prevent rust, but there is probably a better alternative to this. I don't want to run straight water and have all the slats rust together so I can't take them out to replace them.

Reference guide should be out there from the manufacturer that you are using
Torch height, should be the same answer
water table, I run my table everyday, the magic elixir is water, rust is going to happen

 

[LScout800]

After using the table for a bit I was done dealing with the belts stretching, and not having a z-axis. Did not really notice issues with cuts over long distances cutting 10 gauge or better sheets, so not to worried about a THC yet, but am keeping one in mind for the future. The consumables getting detroyed quickly and the messy starts are what is annoying.
Picked up some 10mm lead screws.

Also got a little Nema 17 with an integrated lead screw for the Z-axis.

Almost done drafting up the rest of the parts, then just need to print them. Hoping to get this table done this weekend, the lead screws and Z-axis should improve it quite a bit. Going to research more on a THC setup for the future, would like to make my own original design just to learn more about coding and computers and all that fun stuff, but we will see.

 

[Squatch]

Fuck yes.

I'm dabbling in 3d printing now, and I've been thinking about trying to build a small plasma table.

 

[LScout800]

Fuck yes.

I'm dabbling in 3d printing now, and I've been thinking about trying to build a small plasma table.

Do it. This table is perfect for 99% of stuff I will need to do. Saves so much time rather than having to cut tabs and stuff out by hand, or having to modify stuff from ruffstuff or barnes. Don't see myself needing one much bigger than this for anything on a rig except maybe an axle truss. Plus my local steel yard has scrap cutoff sheets that fit perfect on this that they sell for scrap weight.

 

[LScout800]

Ok got the table working, still no z-axis yet, was going to put together one this week, but the table works pretty good.

It is very accurate now with holes that are actually round and corners that are actually 90 degrees.

Still having one issue, namely concentricity on holes in 1/4 inch. It is a setting issue, so have to play woth those a little more. If someone can give me some pointers I would appreciate it.

Also despite how unstable it looks I can put my full weight on it and shake it with no issues. Going to add diagnal braces once they come in this week.

 

[LScout800]

This is the settings table in the plasma cutter manual I have been referencing.

 

[LScout800]

I cut a lot more holes into the plate, by turning up amps, turning up airflow, and reducing travel speed I am getting good holes (maybe 10-20 thou. out of round) with little to no slag. The concentrucity issue is due to consumables getting messed up after a couple holes due to the pierce. A z-axis should solve that. After I change consumables the holes are perfect, but quickly deteriorate after a few more.

 

[SomeGuyFromOlympia]

I cut a lot more holes into the plate, by turning up amps, turning up airflow, and reducing travel speed I am getting good holes (maybe 10-20 thou. out of round) with little to no slag. The concentrucity issue is due to consumables getting messed up after a couple holes due to the pierce. A z-axis should solve that. After I change consumables the holes are perfect, but quickly deteriorate after a few more.

if your air clean and dry?

 

[LScout800]

if your air clean and dry?

I have an air dryer coming in this week.

 

[SomeGuyFromOlympia]

I have an air dryer coming in this week.

that will help
I run a tank drop, water separator, refrigerated air dryer, and it ands up crossing three dirt legs by the time I get to the cutting table , then another filter dryer just because before it gets to the machine

I have not had anything get past the refrigerated dryer

food for thought

 

[AKnate]

I just watched this video the other week - he uses an inexpensive laser table:


It proves there are options to get set up with CNC plasma fairly inexpensively. Obviously, it's not a production machine, but it could get certain people up and running.

Interesting.

Though that guy makes me want to punch baby seals for some reason.

 

[PAToyota]

Not sure what sets you off about him. He seems to be pretty handy about things. He recently had a shop fire and is rebuilding. Here he puts his power hammer back together:

 

[AKnate]

Not sure what sets you off about him. He seems to be pretty handy about things. He recently had a shop fire and is rebuilding. Here he puts his power hammer back together:

I think mostly the way he talks and goes "hehehe" constantly. Seems dumb, but it somehow grates on my nerves like nails on a chalkboard.

I tried watching that video and turned it off after yelling STFU at the computer.

 

[PAToyota]

Yeah, I get that. I think it's just being awkward and uncomfortable on camera, which I also totally get.

 

[CarterKraft]

In!

I'm doing a sloppy mechanics style build, hoping to soak up all the info I can.

 

[CarterKraft]

Yeah, I get that. I think it's just being awkward and uncomfortable on camera, which I also totally get.

Yeah no shit, try looking at your phone and telling a story to it, feels extra gay.

 

[LScout800]

Any advice on getting rid of a bevel? Only happens one way and is roughly 45°. Setting seem to have no influence, running 1.5 mm from torch tip to work piece.
Also got design number 4 coming along. Here is a picture of the solidworks model so far. Still need to finish up the Z-Axis. It is going to be much more stable.

Going to have a wooden bench to sit on, it will get casters and a place to store all the electronics and plasma cutter underneath. The Y-axis and X-axis are going to be getting a lot more support. Also how do I keep the leadscrews from slipping in the couplings? I will probably JB weld them once I get this thing established since I don't see them having to be changed out in the future.

 

[CarterKraft]

Any advice on getting rid of a bevel? Only happens one way and is roughly 45°. Setting seem to have no influence, running 1.5 mm from torch tip to work piece.
Also got design number 4 coming along. Here is a picture of the solidworks model so far. Still need to finish up the Z-Axis. It is going to be much more stable.

Going to have a wooden bench to sit on, it will get casters and a place to store all the electronics and plasma cutter underneath. The Y-axis and X-axis are going to be getting a lot more support. Also how do I keep the leadscrews from slipping in the couplings? I will probably JB weld them once I get this thing established since I don't see them having to be changed out in the future.

that's got to be a consumable issue right?
try rotating the nozzle to test.

 

[LScout800]

that's got to be a consumable issue right?
try rotating the nozzle to test.

Changed the consumables, same issue. Rotating the nozzle does affect the bevel.
I have an air dryer on there.

 

[CarterKraft]

Changed the consumables, same issue. Rotating the nozzle does affect the bevel.
I have an air dryer on there.

You change the entire assembly, all pieces?
I have had that before on my chi-com plasma and it was a combination of worn electrode, misaligned nozzle on the crappy torch.

 

[LScout800]

You change the entire assembly, all pieces?
I have had that before on my chi-com plasma and it was a combination of worn electrode, misaligned nozzle on the crappy torch.

I changed the nozzle and the electrode. I also ordered some consumables from another manuafacturer (probably same exact thing different name) to see if it makes a difference.