I'm putting together a RF-45 conversion that already has a 2hp VFD controlled spindle. The VFD is a Delta VFD015E21A. I would like to get this machine to where I can rigid tap. So I've been researching and it seems that the VFD/motor combo is ok and I will need to add a braking resistor and tie an encoder to the spindle. Beyond that I have no further clue how to proceed. It will be a while before I am actually ready, but I'd like to at least start trying to figure this out. So to start I have these questions:
1. What PPR encoder should I be looking for? I'll be getting one with index.
2. So the encoder will take 3 inputs (A, B, Index). Correct?
2. How do I figure out what braking resistor I need to get and where are good places to get them?
3. Is rigid tapping do-able on a parallel port system or do I have to think about Mesa stuff? A single parallel port would have enough pins for my needs if I have everything above correct.
4. Any guides out there like "Rigid Tapping For Dummies"
1. If you are reading the encoder with a parallel port 100 or so PPR (400 counts/turn) is a reasonable number
this would give you 2.5 oversampling at 600 RPM even with a quite lousy base thread of 100 usec ( 10 KHz sampling, 4 KHz count rate )
2. Yes
2A. depends on the VFD, the VFD manual should have specs if the resistor is external or at least the current rating of the brake output
3. Yes rigid tapping works fine with parallel port systems, you just have a upper bound on encoder resolution*tapping speed
4. Not that I know of, there's always LinuxCNC docs or asking on the LinuxCNC forum