"precision" plasma cutter?

[sarepairman2]

do they have plasma cutter tools that are fairly precise and meant more for cutting thin metal?

kind of like a pen style .

so you can really get up close to something with a shield and cut out fairly complicated shapes that can later be filed to perfection.

the plasma cutters that I see for sale have big right angle guns, which seem suitable for cutting big shit for automotive work etc. Do they have tiny ones good for say, making a chassis? without a CNC machine.

[DTJ]

I'm not sure precision and hand held can be applied to plasma cutters.

On a NC gantry they can cut quite precisely. As I understand it they are used by some sheet metal shops for chassis and enclosure work.

Google some uTube videos, lots of nice toys.

[sarepairman2]

well whats the smallest type of hole you can make or more complicated shape you can make with one of the hand held angle ones?

i guess the logistics of safely using a "plasma pen" must be worked out..

i imagined like a microswitch in the handle instead of a gigantic push button , some kind of heavy rubber mat you can possibly lean on, much smaller nozzle... can you make it the size of a soldering iron ?



this would be because my body is CNC machine, i don't want to deal with telling a robot how to do something.

I could for instance make a enclosure 90% of the way and then use good files to round things out/make precise shapes.

maybe I just like filing, i find that you can make something pretty darn nice with a file and it does not feel like too much work.. kind of pleasant actually... so long you have nice files

[SeanB]

You can get precise work out if you simply use a pair of clamps and a non flammable ( preferably, or just consider it a single use item, or keep a bucket of water close by) guide, so that the torch will follow the set line with reasonable precision.  That will, if you make a guide to control the cutter head, enable you to make a straight line, or follow a predefined curve. Otherwise it will look like a drunken sailor trying to walk uphill after a hard night on the town.

Otherwise use a NC miller, and make an adaptor to hold the torch, which has been done. For circular holes you can make a simple jig that enables you to have the torch do a precise circle. If you want better accuracy you use a laser with a gas feed to burn the cut, that at least is going to give a better edge.

Yes, just bought a plasma cutter, I make great lines that are straight, at least they mostly follow the confines of the sheet, aside from those that wander all over the place. I will have to make up some jigs to use it, simple wood edges will suffice for me.

[sarepairman2]

what leads to this drunken sailor effect?

i assume your hands are steady. wandering arc?

what happens if you make a template over something then use the plasma cutter? like put a sheet of laser cut kapton over it (pcb stencil)/? (i.e. your front panel cut outs are holes in a sheet of it)

[SeanB]

Drunken sailor because you cannot effectively see the marking on the sheet with the welding glasses. A guide is definitely needed, though what the plasma cutter is intended for will not be looking too good when the little pieces ( it currently is still in use, but I am waiting for the final OK to do the 1 day conversion into metal floor tiles plus a lot of smoke, along with a 200kg gearbox block) are on the trolley going out the door. It was assembled on site, so will go out similarly. I will keep the manufacturers plate though and some parts....

Plus it was my first time with the plasma cutter, trying out the assorted settings, pressures and such, and using the scrap steel I had lying around in the drum at work. I got a few straight lines, but it was hard to cut through a disposable MAPP gas tank neatly. No, I was not stupid, I had long ago vented it by removing the Schraeder valves in it. I just wanted to see how I could cut on a curved surface - turns out I need more practise. Need to do more next week, there are still 2 other drums to test, though the one with perfume in it will be incredibly fragrant.

[sarepairman2]

hmmmm i wonder if there is a market for some kind of dead reckoning system for the more advanced welding glasses.

that keeps your part and tool lined up on a display with some kind of faded snapshot or something...