Looking for info on CNC Plasma

Looking to get one, and was wanting some info on cut part quality, edge, hole, etc. What are realistic expectations of tolerances, not just what their brochures say. Any other gotchas?

Whatever table/unit, was planning on a hypertherm xp45 for the torch.

Thanks in advance.

I have a 4x8 star labs with a hypertherm 85.

The torch works well, the height control is the bane of my existence. It works about 80% of the time and scraps the part the other 20.

I can hold about ± .030 with it. Better requires a fair bit of futzing, especially on smaller holes.

Holes inevitably blow out the corner a bit where the path overlaps, even helixing in from the center.

For holes that have to be accurate and round I burn them small and clean them up with a step drill.

For occasional use (R&D and automation) it is useful. If I was trying to make money with it I would be very unhappy.

I presume some other controller has a working height control, what the height control does isn't complicated.

Acceleration is the most important machine parameter for cut quality. I

Hope that helps.

I cut steel and aluminum a lot on ours so give me a day or two and I'll try to post about what conditions we use, how to minimize pierce issues, and optimizing for cut quality or deburring or speed.

We use a powermax85 with a shallow water table (water gets hot way too fast and rapidly produces hydrogen and clay foam, which is a nuisance when cutting aluminum). We now do all of our aluminum with liquid nitrogen whenever we can but air gives good results too.

I'll chime in a w/ a few things... I am not picking one vendor over another, just noting my rig. check out precisionplasmacnc.llc and CandCNC. com for some decent startup and professional level kits and rigs. They have Digi-torch-height-control that does work. (mine does anyway). I have a lower end Chinese Plasma unit. My biggest mistake was not doing a Hypertherm. So don't skimp there IMO. For quality and edge... that's the magic-sauce! Experimenting and learning my table was key. Keep logbooks and notes on what worked well. (My 2 cents). I've cut 30+ parts on a nested setup and not had an issue. Large signs w/ 20+ cutouts, etc. All should work well if you get a proven and reliable setup. For Edge, I have hardly any dross and minimal post cut work. A wire brush or a few knocks w/ the brass hammer. IT is fun! I do enjoy the table. I hate Alum. cutting. Still not there w/ it, but I can get it done. Still, it's not as easy as Steel (to me yet)... I cut small down.. down in the .5inch range up to 4ft. The kerf width is .06 or so. It'll widen a bit as the tip consumible wear. Also if you do not have the height off the material right.. think flashlight beam 2inches -vs- 2feet on the ground. (My S45 elcheapo is more like a cone discharge). so placement is important. Clean air. Dry air. I run a dedicated 40gal w/ 1/2 hose and high flow connectors. It's more of a journey than some of the other CNC things we've done here. Ohh, and beak-away tourch is a big plus. tip-ups, and torch bump is much easier to recover from with a break-away torch mount. We made our own.

I would suggest going to PlasmaSpider.com - Index page That forum is an excellent source of info for entry level tables and build your own as well. There are many threads for different brand tables.

I built my own table capable of cutting 5x12 sheets. I run electronics from candcnc and am very happy with that system. Their torch height controls are awesome. We cut a lot of aluminum tread plate face up, and the torch has no problems following the raised contours. I also run a hypertherm powermax 85 on this table and get excellent cut quality on 1/16 material all the way up to 1" material. Feel free to PM me if you would like more info.

In order of importance for basic plasma work I'd suggest this order- power source, height control, machine control, machine.

Dialing in my THC was like opening the ark of the covenant.

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Powermax 45 does not cut very thick materials. If you are spending the money on a new table spend a few extra $$ and go with at least an 85. There are a ton of tables on the market. It all depends what you are wanting to cut on it. Wall art or production parts? Attention to detail and tweaking of your settings goes a long ways. There are many variables to consider when talking tolerance. Some people are fine with a 1/32 or 1/16 tolerance. If your machine is sturdy, has accurate repeatability and you do your homework it is possible to get very nice parts off of a plasma.

1. set budget.
2. define work parameters. How thick of metal and how big the product.
3. ease of operation/ learning curve
4. Join Plasmaspider and read anything Jim Colt wrote.

I wanted to do artwork/gates/signs, so I went with a used Plasmacam 4x4 table I found on Plasmaspider. $6k. Found a Hypertherm 45 on craigslist for $800. This got me rolling. Plasmacam software is extremely easy to learn. This worked for a while, until I started cutting firepits out of 1/4" plate. Forklift, $5k.
customer

Ok I'm back.

$3k for 80 amp Hypertherm ('cause I got a forklift and can lift heavyer plate), $800? for Duramax torch, (money well spent over cutting with the "T123" torch)air dryer, table vent, yadayada....

I love the thing and would would have a hard time doing without it. My wife does most of the artsy stuff and I do the mechanical weldment stuff. Bumpers are a breeze. The hieght control has a learning curve but you can get help on plasmaspider. Jim is on this site as well. You'll think its great until you see an industrial table in use.
Well worth the money
have fun
i_r_

I have a bulltear 5x10 (now starlab) and love it. Bought new in 2013 and still going strong.

THC is fussy on most of these hobby level tables...sort of an add-on.

Many people get them dialed in to a sweet spot. Me? I've created several tools in sheetcam over the years but never had a need to really dial it in. It does fine for my needs.

When I need perfect holes I blast a .041 radius hole (Beam of plasma is a nominal .080 so you have to draw the hole like that) and then punch with ironworker.

I use a powermax 45 and haven't really had much need for larger. I've cut 1/2" with it slowly and it did fine.

If you use these as a fab tool you're fine, if you think it's going to be a machine tool (or even a laser or waterjet) you might be disappointed.

Mine is on every day for 8-9 hours. I've had small issues here and there but it plugs away.

Hornet, Meisser, or Controlled Automation. I think Hornet has the best torch set-up, hard to beat controlled automation's service and quality. If you stay up on it a 64th is possible- holes just kind of suck on any (compared to punch or drill). Use straight (70 degrees lead in and the hole will maintain more squareness, lead out (60 degrees)with 1.5 x full kerf overburn, height control disabled on holes.
these are not powermax 45/85 systems tho.

All great info. My concern/fear is expecting like a laser, and not getting that and being disappointed. Was anticipating cutting 1/2" or less, but have always been a rather have it and not need it, then to need it and not have it when it comes to these kinds of things. Will check out the plasma spider site.

Also thinking it might be best to head down to teh local welding supply store and see if they have any customers with one, and see if they'd mind showing what kind of quality they get with theirs.

memphisjed said:

Hornet, Meisser, or Controlled Automation. I think Hornet has the best torch set-up, hard to beat controlled automation's service and quality. If you stay up on it a 64th is possible- holes just kind of suck on any (compared to punch or drill). Use straight (70 degrees lead in and the hole will maintain more squareness, lead out (60 degrees)with 1.5 x full kerf overburn, height control disabled on holes.
these are not powermax 45/85 systems tho.

Click to expand...

Why disable thc on holes?

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Cole2534 said:

Why disable thc on holes?

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Click to expand...

IIRC, a couple of years ago, Hypertherm and others came out with "True hole technology"

Basically a special subroutine for holes.

It plays with both the current, and torch height during the pierce, and the rest of the hole.

I could be all wet on this though....it's been raining all night & day....

Cole2534 said:

Why disable thc on holes?

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Click to expand...

Holes are often cut at 60% speed or so to reduce taper. THC would need to be adjusted, and it's easier to just disable it.

true hole is 60% slower, initial height +25%, straight lead ins, no lead out on hypertherms pre set settings. Controller is shut off during cut to ignore any voltage, grit, water readings - gives the hole its smooth features (and extra dross). SmallHole is almost the same, runs 30% slower, and uses arc for lead out, straight for lead in. You can usually find the button to convert to arc lead in, which gives a smoother entrance yet leaves tapered hole, that split second machine 'pauses' with straight lead in allows plasma stream to catch up to torch, starting the hole straight.
There is a higher shield or cut gas initially, I forget which.

.."If you knew chuck-e like I knew chuck-e" .. .(LOL) Had too guys. his voice is unmistakable if you've been on YouTube. I like his stuff usually and he's witty enough. Then add in the legend and master of the Plasma cutting forum: Jim Colt. (IMO). Mr. Colt has put out copious info on the subject of plasma and CNC use. Video's , tips, Tricks. etc.
Here is a video for you. YouTube Chuck-e w/ Jim. Plenty more out there. Same w/ CandCNC on youtube. I thank my 17 old Kid for turning my onto YT some years back for this type of research. I never looked back and use it all the time now. Hope it helps in some way for ya? Let us know what you think or choose. So many others will have your Q. and find this thread.

SamH said:

All great info. My concern/fear is expecting like a laser, and not getting that and being disappointed. Was anticipating cutting 1/2" or less, but have always been a rather have it and not need it, then to need it and not have it when it comes to these kinds of things. Will check out the plasma spider site.

Also thinking it might be best to head down to teh local welding supply store and see if they have any customers with one, and see if they'd mind showing what kind of quality they get with theirs.

Click to expand...