Pitch Accuracy of Different Cutting Machines, can you help ?

[opcode66]

I totally agree...why not build a whole new turntable and pitch/depth control, designed with todays technology, that is meant to be used for cutting? Probably a pretty expensive endeavour, but a very worthy one!

Already working on the updated pitch/depth control unit.... In about a year I hope to have a solid working beta. Things are already going very well. I have a thread on this board regarding that project.

Don't know a lot about dc control circuits. Only what I've studied. No hands on knowledge. So, that would be a fairly tough undertaking for myself without a little help. Nudge Nudge, Wink Wink. A wink is as good as a nudge to a blind bat...

Ideally, one could take a brushless style heavy duty dc motor from a commercial washing machine and fit it with a custom dc motor control circtuit. This circuit is roughly the same thing as the Program Controller box from a VMS system. Together, they would form a platter driving system that was highly accurate and full of torque.

[Factorcuts]

I like the sound of that!!

[mossboss]

Opcode
Some time back the discussion here about motors went a fair way There was some exchange and banter on it
Flo suggested a dc motor from a motorised bicycle my suggestion was a Fisher Paykel washing machine motor ex NZ which is a flat motor about a couple of inces thick and around 12 odd inches in diameter The idea being you fix the shaft and let the case spin with platter mounted on the case
Another motor from a Miele washing machine that has already an elaborate DC control as it goes from 0-33000 rpm quite a monster but brushless DC while the Fisher is a flat wound AC motor with a fairly decent control incorporating full torque due to ac multiple pulsing
Further thought resulted in the following view
The cutters used in the silicon industry are driven from the outside perimeter cutting the crystals with in a hole of the blade right in the centre
This tends to minimise motor flactuations vibrations wow and flutter giving a perfectely flat cut on a wafer
All of the above issues are divided therefore minimised on a pro rata ratio from the outside perimeter to the centre
So a decent dc or ac motor such as above driving a platter through a sun gear as used in automotive transmissions with a 10-12 to 1 reduction ratio and driven from the centre while the platter is mounted on the casing should achieve the same results while driving the motor at a much higher speed than require for cutting at 33.3 or 45 RPM
Food for thought
Cheers

[opcode66]

Wow, that's already got me thinking!!! Thanks Mossy!

[andybee]

uuups

[Tron]

the guy from ASIA using the Neumann lathe as super good turntable! LOL!