This morming I decided to finally get off my lazy butt and ressurrect my old X2 CNC, to use for drilling and tapping.  I grabbed the old E-box off that was on my knee mill until a couple of weeks ago, and the old PC that was running the knee mill until a couple of months ago, installed some G201s, and connected everything up.  After re-configuring Mach, and installing the same version I've been using for months (3.042.020), it's working.  Well, sorta....  kinda....  The Z axis works fine, nice and smooth and fast.  But X and Y are *really* ragged, and very slow.  Funny thing is, they're all running on the same parallel port!  I looked at the pulse timing on Z, and the pulses are nice and consistent, and pretty evenly spaced.  On X and Y, they're all over the place!  How can that be?

I ran DriverTest, and, despite the fact that this is a lowly 540MHz machine, DriverTest says it's excellent, even at 45kHz, though I'm only running 25kHz.  I ran this machine for years on both the X2 and then the knee mill, and it always performed very well, and I never had a single problem that was positively pinned on the low CPU speed (though it is a dual CPU machine).

I also tried moving to a different printer port (I have 3), and they were no better.

So, how can I get good pulsing on Z, and lousy pulsing on X and Y??

Regards,
Ray L.

Ray, dumb question but is it possible it's the X and Y axis on the machine that's sticking since it's been sitting?

Dave

Ray, dumb question but is it possible it's the X and Y axis on the machine that's sticking since it's been sitting?

Dave

Dave,

No, they turn very smoothly and easily.

Regards,
Ray L.

try swapping around wires and see if the problems follow.
Hood

Well, I suppose I shouldn't be surprised at this point - It was a  BOB problem, just the latest of many.  It's working now.

Regards,
Ray L.

A little off the subject as i don't have use any BOB. But sometimes i think they should rename BOB to mean
BAD OPTIONAL BOARD.   
RICH

A little off the subject as i don't have use any BOB. But sometimes i think they should rename BOB to mean
BAD OPTIONAL BOARD.   
RICH

I think that term may just apply to specific brands

Hood

A little off the subject as i don't have use any BOB. But sometimes i think they should rename BOB to mean
BAD OPTIONAL BOARD.   
RICH

Rich,

I agree.  This was has been nothing but grief.  I've had to modify it just to make it work as it should.  Then I had to modify it again, to make it work with the SmoothStepper.  Now I'll have to un-modify to work without the SmoothStepper.  I just built up a new E-Box, and used two of Peter Homanns nice, simple buffered BOBs.  They just work, and the're dirt cheap.  And his spindle speed controller works about 1000X better than the one on this BOB ever has - very linear, and very accurate at all speeds.  This other one, there were whole days it just wouldn't work, and I had to just find something else to do, since it's kinda hard to do much milling if the spindle don't spin.

Regards,
Ray L.