Sherline Lathe Conversion ?

Yes, 60 ppr should be OK normally

60 slots x 4 for quadrature X 400 rpm = 625µS per pulse.

Is the encoder counter function definitely connected to the base thread and not the servo thread?

Can you attach the HAL and INI files?

Ok, so I am a newbie, when it comes to linuxcnc, well the cnc part. I have an idea what that means, but that's where that stops.

I'll attach the hal and ini files that I am using for the Lathe.

thanks!,

Ron

Ron:

I can't help much. It's been quite awhile since I set this system up and my memory is terrible.

But I do remember working to connect the encoder to the parallel port. It wasn't trivial and I was making slow progress. Then I checked the specs on the Gecko G540 which I used. The I/O for the G540 does some electronic magic which allowed the encoder to connect directly. It also provided a power supply I used for the encoder. So it could be your BOB? Sorry, I'm fuzzy on details, as I said, I haven't messed with the connection for several years.

But to work at low RPM and cause problems at higher, I'd suspect timing errors first. Andy has infinitely more experience that I and can help you with linuxCNC configuration.

I hope this is of help.

Hugh

rocr wrote: I am using a breakoutboard (bob) and everything seems to be working.

well,

thanks for replying anyway. I thought since you had the same stuff, that you had figured it out.

thanks!

Ron

Also what breakout board are you using. Some breakout boards (especially cheap ones) have slow optical isolators on their inputs, not suitable for reading encoders at any reasonable speed. You might need to bypass these. (That is essentially what Hugh did by routing his encoder inputs through the un-isolated inputs of his 540 rather than through an isolated breakout board.)

Your base thread speed may still be an issue as well. All though it should be able to read the encoder faster than 400 rpm. I think It ought to be able to read up to about 2000 rpm.

Can you find the specs on the opto-couplers? (This could be easy if the markings are vsible, or impossible if they have been sanded off, as sometimes happens)