Hey Guys. I have a question. I have some standard 270 oz steppers that are thunking on nearly every single or two rotations. Not loosing steps I don't think, but this is a new occurrence.
I had them hooked up to a Xylotex 3 axis drive. These were previously working fine on my router with this setup. No thunking then.
I swapped the drives for 3 203V gecko's and tuned them and they still do this. I am only using a 28 volt PS. That is the same one that was always on here.
I tried a few settings in Mach 3, but still having the issue. I have a fairly recent (within the last two months) version of Mach 3 installed.
Any ideas?
Thanks a bunch.

Hey Lee,
    Are you sure it is the motor an not something else in the drive mech. like a belt, screw whip, shafts not aligned, pulley set screw loose in pulley, etc. You could disconnect the motor from the mechanical connection and test to help narrow it down.

Brett

Yes, I am positive it is in the motors. I removed all three. These are direct driving some ground ball screws. I am going to try to up my frequency to 35,000. It is kind of puzzling that all three started doing this at the same time. Swapping to the gecko's eliminated the drives. I have tried the active high/low settings. I have changed the two pulse US timing settings in motor tuning. I did cut out my first part on this yesterday and it came out perfect size. Clean cuts, but I think it could be even cleaner without the thunking. I am pretty sure is actually stopping in those points for an instant. Otherwise, how would it make noise?
Thanks so far. It seems like it should be an easy thing to figure out, just haven't run into this before.
Here are a couple images of the mill.
I have done a little more work to it. I added way covers and I am adding an aluminum tray to catch the coolant.
I pulled the chain drive off the front and installed the Y motor direct drive like the other two. I get very nice smooth action except for the thunking.

Just a thought, have you tried a different keyboard? I see you have a flexi. in the pics. Think I remember seeing a while back one of those giving trouble. The only thought I have is maybe a noise problem.

Nice looking machine.

Brett

Thanks, Brett. That is something I would not have thought of. I have another flexi that I use on my router. It seems to work okay. I did have some issue with this one when I use the adapter and plug in beside the mouse.  USB worked okay. I will try another keyboard.

You nailed it, Brett. It was indeed the keyboard. Thanks a bunch.