Plasma cutter tracing machine.

[Shield Arc]

This guy is advertising these on my local Craig's list. $95.00 for a kit. $225.00 + shipping for a complete unit. Over the years I've seen similar units for oxygen acetylene cutting. Never used one, but they do look interesting.:licking:

pattern trace movie.wmv - YouTube

 

[Hooked_on_HP]

That is cool. The only problem I see is that you have to have a dedicated table to set it up on. You wouldn't want to move it often. I am assumeing you have to make sure it is perfectly 90deg to the mounting table. Other wise your arc length will change the further away from the mount that you get.
Bill

 

[CNC Dan]

you used to see them with a magnetic stylus that was turned with an electric motor, used with a O/A torch. The turning stylus would walk it's way arround the pattern at a steady pace. But one thing to keep in mind is that the stylus needs to be the same size as the kerf or your cut piece won't be the same size as the pattern. With my plasma cutter, the kerf width is about 0.050" wide. That makes for a very small stylus.

 

[charlz]

I saw the same thing on my local Craigslist as well. The kerf info is good to know, I was wondering why the stylus looked so small/weak. I have thought of making a grapple but having a way to cut the parts all the same has held me off. Something like this could certainly fix that issue.

 

[CBW1999]

Wow- that is cool!

Should I ever get to the point of having a plasma cutter- I would definatly want one.

Good point on the stylus (no pun intended).

 

[Shield Arc]

On a few occasions I've played with the numbers on my CNC table, and had it cut with in .007 of an inch. Somewhere around here I have a chart that tells me how much to add to the cut for what size nozzle I'm using.

 

[grsthegreat]

I've also seen the same/similar units used with cutting torches. Ive been spoiled with my plasma table though. I made a chart of kerf thicknesses a long time ago, made it by cutting thru actual different thicknesses of plate metals with different cutting tips and amps/speeds.

The current program that i use to produce my .tap files that control the plasma cutting automatically adjusts for kerf thickness as i render the drawings.

its sure easy to get spoiled.

 

[jake98]

$225 seems reasonable enough. guess you could make one out of plywood and piano hinges, if you didn't need too much accuracy. I did some freehand thru 3/4" plate today, that wasn't pretty..

 

[CNC Dan]

I saw the same thing on my local Craigslist as well. The kerf info is good to know, I was wondering why the stylus looked so small/weak. I have thought of making a grapple but having a way to cut the parts all the same has held me off. Something like this could certainly fix that issue.

just make a template out of plywood and allow for the nozzle size and kerf width.

see my first few posts to see the template i used to make some hinge brackets.

 

[mjncad]

That gizmo is nothing more than a pantograph, and it looks pretty decent for the price. However; I think it might be easier to use if the pattern holding arm/stylus was closer to the parts being cut. It appears to me that there would be a lot of looking up and down, making it easy to have the stylus slip off the pattern.

I'd say the tool is better than nothing; but if you have CNC plasma/laser/waterjet available to you, I'd go that route first.