CNC plasma cutter build

C-Bag

Ned Ludd's bro
H-M Supporter Gold Member
Joined
Feb 9, 2017
Messages
2,878
There were several factors that stopped me from getting a full size plasma table. Besides the learning curve and for my parts plasma anneals the steel on my thin parts and makes it too soft, major problem was the air pollution in the shop. This is where I think water jet has plasma and laser both beat. Does the design you are making address that? I've not been around a table with a water tank under it, but I would think that would mitigate the toxic fumes somewhat?
 

DavidR8

Soaking up knowledge!
H-M Platinum Supporter
Joined
Oct 16, 2019
Messages
4,468
Waterjet is a whole different animal to be sure. I've never seen it in action in person though.
Plasma I have seen and the difference between having a water table and not is pretty significant. Without, sparks go everywhere whereas the water table catches much of the sparks. It's still a bit smoky though.
I plan to build a detachable water table that will connect to my welding table.
 
Last edited:

vtcnc

Admin
Staff member
H-M Supporter - Commercial Member
Joined
Jun 29, 2014
Messages
2,346
Waterjet is a whole different animal to be sure. I've never seen it in action in person though.
Plasma I have seen and the difference between having a water table and not is pretty significant. Without, sparks go everywhere whereas the water table catches much of the sparks. It's still a bit smoky though.
I plan to build a detachable water table that will connect to my welding table.
Just make sure you let the water evaporate off and don't dump it down the drain. You wastewater district will detect the heavy metals and come a-knockin'. You should be able to sell the remaining slag with your scrap all in one barrel.
 

DavidR8

Soaking up knowledge!
H-M Platinum Supporter
Joined
Oct 16, 2019
Messages
4,468
Just make sure you let the water evaporate off and don't dump it down the drain. You wastewater district will detect the heavy metals and come a-knockin'. You should be able to sell the remaining slag with your scrap all in one barrel.
Thank you, that is a very good thing to know!
 

extropic

Active User
H-M Lifetime Diamond Member
Joined
Nov 24, 2014
Messages
1,225
I know very little about plasma cutters. I've seen a video where the CNC machine had a Z axis mechanism that detected and controlled the torch height from the stock. As I recall, the torch in the video needed to be very close to the stock to "start" and a little higher during the "run".
Also, the Z sensor maintained torch height over warped stock.

I don't see that type of Z control on your machine so . . .
Are you going to use a torch that "starts" and "runs" at the same height or ???
What are your expectations regarding cutting warped stock. In other words, what is the torch to stock tolerance during a cut?

I like the small portable machine concept. I imagine much larger parts could be made by subdividing the cutting into routines that fit within the X-Y envelope of the machine and re-indexing the stock. Is that part of your plan?

Great project, IMHO.
 

koenbro

H-M Supporter - Gold Member
H-M Supporter Gold Member
Joined
Feb 23, 2016
Messages
75
I do think torch height control is important. I also would not use my plasma without the water table — building v one is probably the easier part of such a project.


Sent from my iPhone using Tapatalk Pro
 

DavidR8

Soaking up knowledge!
H-M Platinum Supporter
Joined
Oct 16, 2019
Messages
4,468
I know very little about plasma cutters. I've seen a video where the CNC machine had a Z axis mechanism that detected and controlled the torch height from the stock. As I recall, the torch in the video needed to be very close to the stock to "start" and a little higher during the "run".
Also, the Z sensor maintained torch height over warped stock.

I don't see that type of Z control on your machine so . . .
Are you going to use a torch that "starts" and "runs" at the same height or ???
What are your expectations regarding cutting warped stock. In other words, what is the torch to stock tolerance during a cut?

I like the small portable machine concept. I imagine much larger parts could be made by subdividing the cutting into routines that fit within the X-Y envelope of the machine and re-indexing the stock. Is that part of your plan?

Great project, IMHO.
To be totally honest this is my first foray into plasma cutting. I know that bigger tables have torch height controls and how I might add that to this is something that I have thought about but no more than that.
I need to do some experimentation with the plasma cutter to see what kind of tolerances are involved.
If I have to add a torch height control (THC) I may have to re-engineer the whole shebang as I'm not sure the Y-axis could support a THC as designed.
 

DAT510

H-M Supporter - Gold Member
H-M Supporter Gold Member
Joined
Oct 20, 2016
Messages
514
Plasma cutters ~<40amps can be used in drag cutting mode, (Typically with a drag tip) so if you leave the amperage lower than <40, you can just leave the tip in contact with the metal.
 

extropic

Active User
H-M Lifetime Diamond Member
Joined
Nov 24, 2014
Messages
1,225
Plasma cutters ~<40amps can be used in drag cutting mode, (Typically with a drag tip) so if you leave the amperage lower than <40, you can just leave the tip in contact with the metal.
Would 40 Amps equate to about 3/8" thick steel stock (maybe 1/2" slow cut)?
 

DavidR8

Soaking up knowledge!
H-M Platinum Supporter
Joined
Oct 16, 2019
Messages
4,468
My plasma unit is rated at 60A. It's a blowback start because I didn't want the electrical interference issues associated with high-frequency start. Unless I start building bigger stuff, at this point my projects are all using 1/8" stock.
 
Last edited:
It can take up to an hour for ads to appear on the page. See our code implementation guide for more details. If you already have Auto ad code on your pages there's no need to replace it with this code
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock