IPGregory - QueenAnt Pro V2 Build Thread

[IPGregory]

Looks like we had to reload the forum or something and lost a couple of weeks of posts? I had finished the build part of this thread, but the post is lost so I will update again when I have time just to wrap this up.

[IPGregory]

Drive Tuning?

Every so often I will jog an axis and it will result in a bang or thump before it moves and then it will move normally. Very infrequently I will also get a bang on a sudden direction change during a program run. It doesn't seem to be speed related as I've had it happen on relatively slow runs about 1000mm and nothing on much faster ones. Its more to do with the tool path from what I can tell. When it happens, it will lose position and I will have to re-run the homing sequence to reset the home point. I have been searching the forum, the TBs and the Manual and it seems as though this is something to do with Acceleration/Deceleration or similar settings? There seems to be an option to do an autotune in the PID menu but the manual warns not to use it.

So the question is, how do I 'test/tune' my machine to get an understanding of or set up its max axis movement rates and to know the drives are properly 'tuned' either in hardware or in the SW to avoid sudden bangs and thumps from accel/decel?

Copy of my drive manual and my latest report below if these help and innumerous pics and details of the machine in the thread above?

Link to the Motor/Driver Kit I am using Mfg. Page:
https://www.omc-stepperonline.com/ts-se ... cl57t-s30a

I am running the 4 x Motors on 2 x 36v/350w/110v Meanwell PSUs. 2 motors per PSU

I currently have my drives set to 3200 Microsteps (Sw 1-4 = off, off, on, on). Switches 5, 6 and 7 are all off and Switch 8 is on. All drives set the same.
The rotating switch is in position 8. To start with, I had this set in the middle at 6 and switch 8 above off which is the default, but the banging was worse. setting to rotating 8 and switch 8 on has helped and it is now pretty infrequent, but it's not eliminated it.

I am using a 4000mm/sec max speed for the machine at the moment, but this is an arbitrary number I am using to try and be conservative. I don't know the true max speed of the machine and didn't want to push it until I resolve this axis banging issue.

Thx
Ian

[IPGregory]

Something that was puzzling me on the above is that when I get the bang and I lose position, I don't always get a drive error. I have a closed loop setup so if I get a position mismatch, I would expect to also get a drive error. Thinking it over I may have a mechanical issue as well. Not sure it is a cause of the above but I think it's why I don't always get an error, but I normally do get a position mismatch.

I have these couplers between my motors and my ballscrews.


They don't utilize the flats on the shafts, they just use compression and friction. I do check them to make sure they don't come lose and I have locktite on the grub screws. I am thinking that sometimes when I get the bang due to high acceleration or something then these slip and I get a mismatch between the motor turns and the ballscrew turns. This puts the machine out of position but doesn't throw a lost steps drive error.

If this is the case, does anybody have a recommendation on a better coupler that does use the flats on the shafts but doesn't break every 5 mins? Motor shaft is 8mm dia and the ballscrews are 10mm.

[cnckeith]

Looks like we had to reload the forum or something and lost a couple of weeks of posts? I had finished the build part of this thread, but the post is lost so I will update again when I have time just to wrap this up.

yeah, hostmonster blew away a weeks worth of posts. no sense having daily backups of the forum if your host loses the whole server and has to rebuild from a once a week back up...ugh.. sorry, first time that happened in 12 years, looking into copying daily copies off the host server now.

[IPGregory]

yeah, hostmonster blew away a weeks worth of posts. no sense having daily backups of the forum if your host loses the whole server and has to rebuild from a once a week back up...ugh.. sorry, first time that happened in 12 years, looking into copying daily copies off the host server now.

No worries, I thought it was something like that. Noticed the forum go offline then when it came back it was a week older or so. I can repost the update.

[tblough]

I prefer belts and Fenner trantorque bushings. If you are going to use set screws, you should at least dimple the shaft where the screws touch.

[IPGregory]

I prefer belts and Fenner trantorque bushings. If you are going to use set screws, you should at least dimple the shaft where the screws touch.

I would, but the screws don't go through, they just compress the outer housing of the coupler. It's a friction clamp. My motor shafts have a flat and I can dimple or add a flat to the ballscrew shafts, but it needs a design where the screw goes through to engage the flat or a dimple to do anything.

The replacement ones I have seen so far have plastic or rubber dampers in the middle and apparently are prone to break. These at least are all metal and more of a spring design.

I just took a look at the Fenner Bushings. Don't see a solution that handles 2 different shaft diameters though?

[ShawnM]

Use Loctite 648 on the coupler and shaft, it’s designed exactly for holding components on shafts. Allow for proper cure time.

https://www.henkel-adhesives.com/us/en/ ... e_648.html

[cncsnw]

... then mark your shafts and coupler with a Sharpie, so that if they do slip, you will know at a glance.

[IPGregory]

Use Loctite 648 on the coupler and shaft, it’s designed exactly for holding components on shafts. Allow for proper cure time.

https://www.henkel-adhesives.com/us/en/ ... e_648.html

... then mark your shafts and coupler with a Sharpie, so that if they do slip, you will know at a glance.

Perfect, I will grab some and mark them. Thx for the help guys! I don't think they slip often or much but it's the only thing I can think of that explains how the machine can get into a position mismatch without a drive error after a sudden bang.