Re: Old scanners for CNC parts?

Yes - there are issues abound.

I have used a small 8x10 or there abouts flatbed that uses a 200k RPM very high speed
motor that drives a 10 mil endmill that cuts PCB material.
The motor isn't all that large - it isn't a handful when extracted.  The gantry has to
carry the load and balance it.  The software like most CNC software and Plotter software
has high speed flats and slows down on the corners.   Overshoot isn't a issue at all.

The issue is conversion of a robust unit into a more robust unit.  Maybe the control board
is the main save - since it accepts and translates the plotter control codes.

Martin
Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH & Endowment Member
NRA Second Amendment Task Force Charter Founder



Bill Janssen wrote: 
Martin H. Eastburn wrote:

Find a HP plotter - then just convert the existing pen into a high speed cutter -
then you can plot to it from almost any windows program. Windows to provide the driver....

Martin
Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

The plotter servos may have a problem with the extra mass of the higher weight
of the cutter and motor. Even if the servos have the power needed to drive the cutter
you could experience overshoot and hunting.

Bill K7NOM



Don Stauffer wrote:

Rex B wrote:

I see old flatbed scanners in the trash all the time. Are the internals on these of value for a small CNC conversion?



The key is small. The problem is that the steppers used are very low power. If you drive a carraige with them ( low friction carraige), then use some other force mechanism to move a cutting tool into the workpiece they work. But the steppers do not have the power (force ability, actually) to push a normal cutter into a workpiece very well. Still, if you use a VERY small bit and advance it very slowly, it should work. I saw a mini-cnc-mill for milling printed circuit boards that used small steppers. The mill only went down through the copper, which was about 15 mill, the mill used was 1/32 inch in diameter, and moved rather slowly. It was a neat little deal, much quicker than photo etching a pc board, but you still walked away and came back an hour later.

Still, for a modeler like me this would probably be adequate, and I have been actually looking for such a project article in mags and on net.



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