Re: Now for a change of pace: PlasmaCAM

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Dennis Schmitz"
<denschmitz@...> wrote:

>
> All of this talk of water jet cutters and occasionally lasers led

me

> to this website.
>
> http://www.plasmacam.com/
>
> Apparently you're supposed to buy your own plasma torch, but in any
> case, it's a very spartan design of an xy table with a little bit

of

> z. They claim accuracy of 0.0005 in the xy, making me curious how

they

> built the actuators and bearings. Getting both ends to move

together

> on the first axis seems an issue -- maybe a rod with rack and

pinion

> at both ends would work if you could get rid of the backlash.
>
> Notice that almost all the structural elements are bent sheet metal
> and the cable holder saves a bunch of expense from using a flexible
> wiring channel.
>
> A small handheld plasma torch is a bit expensive at $1500, but it's
> way cheaper than a laser.
>

Yeah, you can build it to do 0.0005" but the problem is that the
torch won't hold that( repeat it) as the tip wears out prety fast.
It's dificult to get a large machine built out of square tubes
strait all the way withing that 0.0005".
The positioning carriages should not be part of the cutting table.
the one I've built has step motors and rack and pinion, and a long
shaft across the table driving both sides of the table.

Fogassa.,