CNC Plasma Cutter: Post Purchase Costs

[Samwaldo]

we (a fellow CT team in Brookfield) JUST got one. Team 1099 worked with the school to get a giant grant to get the Plasma cutter, a laser cutter, A 3D printer, new wet belt sander, and a few other things.

We got a slightly larger one (5' x 5' if I recall correctly) Torchmate CNC plasma cutter. We just finished constructing the table last week and still need to attach the cutter. Theirs alot of extra thing you need to buy. For instance we are setting up a whole new computer next to it, and got a wood router to attach to it also.

I'm not quite sure how much just the plasma cutter + accessories cost because some money came from the grant and some from the tech yearly budget.

If you have any questions i can pass them along to the Tech teacher though.

[magnets]

Personally I don't like plasma cutters for FRC applications. They aren't super accurate (compared to waterjets), and they are expensive and a pain to run. Our team has a CNC router that can cut aluminum (shopbot 4' x 4'), a cnc 3 axis mill, and a really old bridgeport with a DRO.

We make 70% of parts on the bridgeport, 25% on the shopbot, and maybe 5% on the cnc mill.

If you don't have a good bridgeport with DRO/a good lathe, get one of those first.

Cutting sheet aluminum on a cnc router isn't totally ideal, cooling/lubrication is a little trick, and the parameters take a bit to get dialed in, but there is a massive amount of flexibility. We make things out of foam, plywood, and HDPE all of the time.

If you already have a bridgeport/lathe/other cnc machine, you could invest in a plasma cutter, but it depends on your team. Come up with a spreadsheet that shows you if the machine can save you money in the long run compared to sending parts out to be machined.

[mman1506]

We have a plasma cam(6x6?). You cannot use a water table for aluminium as it will collect poisonous gases released when plasma cutting that are heavier than air. We sometimes spray a little water on the collection table we have under it to prevent the dust through being blown into the air. Consumable consumption can change depending on what you're cutting and your operator but its not too bad.

As others has said I would recommend against getting a plasma cutter. It takes a lot of careful calibration to get mediocre results. It works ok for large low tolerance cut-outs and if you just make locating holes by piercing and drill them out you can get reasonable accuracy.

Most of the time are team skips the plasma cutter and uses a shear, band saw and drill press to do large pieces that cant fit on our CNC mill or a manual mill.

[BBray_T1296]

Our team usually gets our stuff laser cut by our local sponsor. Due to their scheduling and priorities, it takes them about 1.5 weeks to finish a part, even though it is only 1-2 hours of work (I worked there this summer). We have discussed getting some sort of small sheet metal cutting machine for quick prototypes and things. Thanks for providing useful knowledge.

[MichaelBick]

Originally Posted by BBray_T1296

Our team usually gets our stuff laser cut by our local sponsor. Due to their scheduling and priorities, it takes them about 1.5 weeks to finish a part, even though it is only 1-2 hours of work (I worked there this summer). We have discussed getting some sort of small sheet metal cutting machine for quick prototypes and things. Thanks for providing useful knowledge.

Look into getting better sponsors. Our first waterjet sponsor took about the same amount of time. We found a new one that returns parts within 5 days, usually much faster. We're looking to find more/faster machine shop sponsors too.

[techhelpbb]

Team 11 has a CNC plasma cutter.

Works great on aluminum for rough cuts.
Gets things down to size.
Allows for really fast testing of things if you don't mind the slop.
Don't expect finished work from it.
Works great for removing unnecessary material to lighten things up.

Team 11 also has: a Bridgeport, bandsaws, several lathes and the Haas TM-1P is now in the shop.
Not quite up and running but soon. There's a Haas lathe on the way.
Plus the Makerbot.

Nothing wrong with the CNC plasma cutter.
Just don't expect it to be the end all and be all of shop tools.
If you can reuse the X/Y for other things that's even better.
Say for example use a real Z instead of a mere up and down and fixture a shop router for some work.

One nice part about CNC plasma cutters is that they tend to be as easy to instruct as pen plotters.
So unlike some other CNC tools it really is possible to run a CNC plasma cutter without touching much G-code.

The Makerbots sort of share this ease of use.
Slic3r is really not something most people use in that work flow but it is there.
Slic3r often comes up with RepRap style printers.
Even at that most people don't manipulate 3D printer G-code at the starter level.

I think of these later tools as introductory tools for the lathes and mills.
It gets increasingly difficult to avoid touching G-code and encountering surprises during operations.