Y axis is making X axis stall...!!

**JAZZCNC** · 06-10-2011

Steve, Smooth stepper on it's way this will eliminate the PP completely. . . Remember thou I want the bugger back.:confused:

**fasteddy** · 06-10-2011

Thanks Jazz..!

Will pop the bugger back as soon as I have tried it..!

Steve..

**Karl** · 06-10-2011

Disconnected the X and Y motors from their X-Y table. Unable to reproduce the problem of horrible sounds and missed steps described above when MACH3 jogging the motors at full speed. I'm becoming convinced that, since the X and Y-axis move very smoothly on their own, that the issue - in my case - is related to some resultant force vector in the heavy X-Y table causing table twisting and thereby increased friction and too high loading on one or both of the the motors (even though motor currents seem low). I can't tell by sound or feel whether it's the X or Y motor generating the noise. A mystery that's annoying and puzzling.

**JAZZCNC** · 06-10-2011

Originally Posted by Karl

Disconnected the X and Y motors from their X-Y table. Unable to reproduce the problem of horrible sounds and missed steps described above when MACH3 jogging the motors at full speed. I'm becoming convinced that, since the X and Y-axis move very smoothly on their own, that the issue - in my case - is related to some resultant force vector in the heavy X-Y table causing table twisting and thereby increased friction and too high loading on one or both of the the motors (even though motor currents seem low). I can't tell by sound or feel whether it's the X or Y motor generating the noise. A mystery that's annoying and puzzling.

Sounds very much like you have some binding then or if it's X-Y table that uses dovetail ways with jib strips then you could have some slop enabling the table to twist and jam.?
If so then I would strip down the table and check for any chips that have got lodged or stuck, clean all surfaces carefully checking for damage or high spots.
Re-lube the ways and rebuild being carefull not to over tighten but still enough take out any slop then try again.

Good luck.!

**JAZZCNC** · 06-10-2011

Steve I'm clutching straws for you here but it may be worth trying another PP cable.?? Will at least be another part of the elimination process.!

I'm pritty sure you have a pulse issue and this where I'd be concentrating my main focus.!

**fasteddy** · 07-10-2011

Think you are right Jazz.. Having revved up my y axis by re-wiring it as parallel, I am guessing that there are more pulses/second now and this may be why I am experiencing even more stalling, the y axis did not stall before and it is now... Your smooth stepper will surely prove this one way or another and I will do as you suggest and get another cable..
As we discussed before, I should probably think about a PCI PP but I remember your thoughts on this.. So, anyone out there know a tried a trusted PCI parallel port that they use on their CNC?

Steve..

**Swarfing** · 07-10-2011

Look fr cards that contain the 'NetMos' chip on it,a lot of the cheap ones on Ebay do, just fire odd a mail asking them. There has been good feedback on these.

**fasteddy** · 07-10-2011

Alrighty..!!!

Finally getting somewhere...! Changed my parallel lead, big difference and stalling was reduced immediately, but not gone... Then dropped micro stepping down to 800 for each axis and then re-sited every wire.. Bingo...! No stalling.. Had it whizzing around the limits of each axis in 45 degree moves for about an hour.. Not one stall.. Gradually ramped up the speed and acceleration of each drive and would have got it up to around 4500mm/min except one of my ballscrews is bent, nearly shook the frame apart..! Just got to remove the dodgy ballscrew as I think the machined (motor) end might by eccentric...

Thanks all so much for your help, wish I had done everything step by step now as I am not certain if reducing micro steps or rewiring it was the cure.. From what I have read on many posts, 800 micro steps should be within easy reach of my PC, so I still think I have a weak parallel port.. Will get a PCI one from ebay (with a NetMos chip, thanks 2eUpoz) and will still try Jazz's smooth stepper (mucho thanks Jazz) as that sounds like a cure all for this type of pulsing problem..

Once I've checked the ballscrew I have a 6 hour job to do so am going to see how it goes with the new settings..

Karl, guess you have tried reducing the micro-stepping on your drivers, if not, got to be worth trying and definitely try a new PP lead as Jazz suggested.. If that does not work, then good luck and please continue the post until you have it working properly..!

Steve...

**Swarfing** · 07-10-2011

Good to hear it's work Steve :-)

by the way the last PP card i bought was from this guy. Had to search quite hard but found him.

http://myworld.ebay.co.uk/fullspeedit

**JAZZCNC** · 07-10-2011

Great news Steve. . I've known a few case's of failing or poor quality cables giving troubles, thou I still think it's your PP causing the problem. Thats why dropping the microstepping works.
Bet if you dropped the kernel speed to 25K you will be able to micro step higher.? . . . Give it a try and I think you'll find you can get 2000 M/S.!

Edit: The only reason to run higher Kernel speeds is if you can get higher speeds from your motor/screws than the kernel allows and your if PP is upto the job.
Other wise Mach works best or should say most stable at 25K. . . . If your happy to run at around 5mtr/min then I would leave it at 25K for best stabilty.