Plasma copy table - no CNC.

[KemppiFrog]

While lusting after a CNC machine for plasma cutting, the cost of a new one or the time and complexity of DIY, for the likely work made me think a fresh.

So, this is the result. The torch is fixed in the cradle at the end of the arm, which works like a drawing machine with parallel acting arms. The design is clipped to the table on the right and followed with the pointer at the end of the ally extension. Due to the action of the arm, the torch will cut exactly where the pointer moves on a 1:1 scale.
The table is a bit bigger than 1X1 mt, so will easily take a half sheet and is set up for water with a drain at the top right. Just need to make the support rails and get a new plasma. I managed to sell my pld 3-ph one and am now looking at single-phase ones and saving up

One of the problems with the arms is back-lash, not bad to the right and bottom, but might become a problem at the top left. If it does, I plan to replace the control arms with light chain and cogs. At the moment, there are springs under the arms to tension the joints so the slack is held one way. It is slight but if the torch catches on slag, it might be an issue.

Any comments?
KF

 

[Robotstar5]

Any comments?

You've got nice light workshop

 

[chunkolini]

Probably deceptively simple.
Then again things that look elegant are usually more complex than they look.
Nice work, you tube clips of it working when you have got it sorted would be good.

 

[KemppiFrog]

You've got nice light workshop

Err, actually that is the barn that I am converting to rent out. Hint, hint.. The workshop is a bit gloomier and even more untidy

Chunkolini, as for utube, getting pix up here is about the limit of my tech skills. But who knows? might give it a go. The camara will do vids. (as my wife found, when she hit the wrong button and photoed mucho ground and trees, rather than the subject).

Next up, my 'not very upset' chop saw.
KF

 

[outofthefire]

I've gone the other way round I bought the rails and linear bearings and a single phase plasma cutter I haven't got a lot further though.

For control and movement of the torch, i'd been thinking along the lines of a sketch-o-graph I had when I was a kid I think I might have to study your design though. Mine is going to be roughly half the size of yours I dont have a lot of free space in the workshop.

 

[KemppiFrog]

A bit of detail, if it helps. The control arms are ally channel with tufnol blocks fitted in each end to make a stable bearing. It helps to mock it up with wooden strips to check the motion of the arm. Try to avoid the angles getting too acute, that causes a problem with backlash. I did think of folding it up against the wall to save space and the table for the paper designs will be detachable, or fold up. But I am not short of space in the various outbuildings here.
KF