Kerf angle comp.

[gridley51]

I once thought that I would build a cnc plasma table.Where I thought I`d ever get the time from I don`t know but anyway I`m past that stage now.One of the things I`d intended doing was mounting the torch so it could be tilted in any orientation by two servo motors at 90 degrees to each other so that the cut could always be square to the part surface.The mechanics of this were very simple,the software not quite so easy.
Has this been done on a commercial basis or does the type of cnc control used on this type of machine not have the processing capacity ,or is it a non starter for a different reason?
Mark.

[Dustin407]

Has this been done on a commercial basis or does the type of cnc control used on this type of machine not have the processing capacity ,or is it a non starter for a different reason? Mark.

Well I think your idea makes great sense to me, but may not be possible. How do you or the servos know what the bevel is at that particular cut spot? You dont... Some bevels are different than others depending on material, cut speed, direction, etc.. I think their are to many factors involved for it to be constant. If it was a constant bevel number it could be fixed, but its never... Instead of spending all that money on something that probably wouldnt work, you could just op for a $15,000 plasma cutter(ouch) that gurantees a perfect 90 deg. edge. This situation sucks but maybe in ten years they will have control software for this purpose once cnc plasmas are more intelligent....

[cowleym]

Hi

Yes it can be done, Flow and Omax have a similar device on their waterjet machines, their process speed is a lot slower than plasma so they have more time to move things around, also the plasma arc tends to wag around a bit anyway, another difficulty is deciding when the head should be at an angle and by how much. I am currently building a similar device, but for beveling plates for ship building. A better soloution may be to find a second hand Hi Def plasma or design out the need for straight edges. Also stick in new consumables for the bits that need to be of a better quality. If you are using a hypertherm powermax plasma try the fine cut consumables, they give pretty good results on thin material. I know it is old technology but gas cutting can give a nicer edge quality on thicker plate, also it doesn't leave such a hard face.

Basically I woudnt bother, but if you did get it going I am sure myself and others would be interested.

Cheers

Mike

[jimcolt]

Kerf angle compensation has been done on some large industrial plasma cutting machine.....always in combination with rotating bevel head devices for continuous contour bevelling. MG Cutting and Welding, Koike Aronson, Esab and other big machine manufacturers have been doing this for many years.

I have not seen this done on small, reasonably priced machines...but the methods used for water jet kerf compensation should be adaptable.

Jim Colt

[gridley51]

Once again,thanks Mike and Jim for the info.I suppose at the end of the day it`s very much the same as bevel contouring.I don`t think there would be an issue with the speed of the servos to control the tilt,more the code writing to angle the head in respect to the direction of travel.
It`s only something I think about in idle moments,I`ve got a reasonable sized cnc machine shop to maintain apart from all the other aspects of running a business so chances are it will never get beyond the thinking stage.
My plasma source is a Hypertherm Max 100,can I use fine cut consumables in that?
I have done a lot of reading of Hypertherm`s website but still don`t know very much about anything,especially what I can all do to improve cut quality.
I`ve started working on the machine.The guide rail on the drive side of the long axis (X?) needs replaced due to wear,will replace the runners at the same time and the cross axis (Y?) needs adjusting to get rid of a fair bit of play.
If anyone can point me in the direction of reading material I would be very obliged.
Mark.

P.S. I think it`s a Hypertherm torch as well but not 100% sure.

[gridley51]

Twice I typed a reply,and twice it disappeared.Now I come back five minutes later and both posts are up here so I`ve wiped one.
Mark.