Teach Wizard A Bit more

[Graham Waterworth]

Would it not be possible to connect a photo diode and do like robots do and search the line and follow it with a macro program.  you could move the x and y axis in say 1mm increments finding the line centre and recording the points.  If the drawing was drawn 5 times size and scaled after the accuracy would be quite good.

Graham

[DAlgie]

Yes, good idea Graham! This is what i've been looking for with what I want to do, which is cut carbon fiber prepreg using the tangential knife setup. I start with cardboard patterns from the mould and have to somehow digitise these, see attached pic, it would be much easier to just arrange them out on the table of my 8' by 4' router and let it do the job automatically. Could attach a photo diode where the knife usually is, have a quick disconnect plug ready above the knife stepper and plug it in there, remove it for the cutting work like an attachment.

[DAlgie]

Maybe could use the guts of this kit http://www.electronickits.com/robot/owi9737.htm It drives two servos for the steering, by running either of the drive wheels, the signal to those wheel servos might be close to something that's useable, probably are DC motors so it sends voltage ranges, could that be converted to Mach's input? I'm no genius with this stuff by any means, know just enough to be dangerous, anyone have an idea?

[Brian Barker]

I was thinking about using a Webcam

[DAlgie]

A webcam, interesting. Readily available, but I have no idea how to interface from a graphical device to digital output, maybe someone could come up with something there. On the line following robot idea, that kit I linked to earlier would just need two ADC controllers, the robot's drive motors input's connected to them, so the output would be digital into the parallel interface board. That gives you a two axis input, all that's needed. OK, so there's the electronic side of it, I don't know anything about writing a macro in Mach to run this "Visual digitising device"

[Brian Barker]

Art was thinking that the code for the webcam would not be that hard

[Graham Waterworth]

Hi Folks,

Why not use the machine to do the moving.
 
Put the output of the photo cell to an input pin so it triggers when it sees white.

Connect the photo cell to the spindle.

move to a start point on the template.

Then using an incremental program move in 1mm arcs until the switch changes.

Record the machine position.

Move again.

If I am talking crap please tell me and I will shut up.

Regards

Graham.

[washcomp]

How about a laser scanner capability for following a line.  I suspect the lenses on many webcams may throw too much distortion into the system unless you limit the "aperture" to a small part of the center of the lens.

Jeff

[SKAR]

I build CNC routers with a concrete base. The attachment points are coupling nuts welded onto the reinforcing before pouring the concrete. As the spacing and grid pattern is not exact, this is where the teach wizard comes in. As the second last step in the build I have to attach a polyprop sheets to cover the concrete surface. I use to Teach wizard to pinpoint the holes, write a drill subroutine and call it between the points I teached. Load on the sheets and drill. Easy!

[Brian Barker]

Are we going to have to add in some drilling to the wizard