I had always thought bipolar series was preferred to get the higher speeds? Is parallel better?
It looks like in Steve's case it's the Y/Z axis motors that are in series, and they're not at fault. Still worth trying, as long as the power supply can take it.
Edit: That said I still don't think this is Steves problem due to him having the problem at lower speeds.?????
Just taken some motor current measurements on my machine - measured at the output of the star-wired PSU:
- Powered up but stationary the 3 drivers and motors together pull 0.87A (DC) total. Motors bipolar series. Driver PM542 settings now 2A (RMS) limited.
- MACH3 jogging X,Y or Z axis individually pulls 1.36A during acceleration levelling at 1.25A - this is the machine's full MACH3 limited speed of 400mm/min.
Jogging in, say, X and then also jogging Y - ie causing the horrible mechanical noises and poor movement - pulls 1.6A to 1.9A total.
Jogging the Z full speed and then - at the same time - jogging either the X or Y in any direction does not cause any problem (likewise moving either X or Y and then engaging Z causes no problem).
My PSU is rated at (43V) 5+ amps so, given the figures above, current does not seemed to be an issue.
I'm wondering if this problem is due to inertia/momentum/twisting forces in the, not very expensive, X-Y table?
Just a quick mention that I am only getting this problem when the X and y are at maximum speed...
Have now re-installed Mach - no difference..
Also tried another PC, although it is a pretty low spec laptop (setup as a standard PC) - no difference..
Going to rewire my nema 23's (3Nm) in bipolar parallel today, not sure if I will be able to do the same with my Nema 34's as they are 4 wire motors, just waiting on a bit of advice on that, unless someone out there knows how to do it?
Just want to say that although I have not got to the bottom of this problem yet (and neither has Karl, my sympathies dude), I am very grateful for all the advice given.. Checking so many aspects of my machine is a real confidence booster with the level of scrutiny it has had this week, I feel like several engineers have checked my work and so far, most of what I have done seems right and a couple of things I have been able to improve..
you cant connect a 4 wire motor in parallel, it is similar performance wise as if you had an 8 wire motor connected in parallel.
Out of interest does this problem happen if you disconnect the ballnuts from their mounts?
Also does the X axis stall when the Y axis is in a specific position or is it random?
My thinking is that is may be a mechanical problem with the stiffness of your machine?Visit Us: www.zappautomation.com
Still happens with the ballnuts disconnected, I had removed the ballnuts last week and cleaned them out, then tested that principle as I was originally thinking along the same lines.. The problem can happen at any position on the bed (2mt x 1.4mt) although it seems to happen much more on moving the x axis +, rather than -..
Mechanically, the machine is sound and I have torn apart and rebuilt it twice in the last week, everything is freely moving..
If I get a chance, I will make a little video of it happening later today..
By Washout in forum Motor Drivers & ControllersReplies: 6Last Post: 10-12-2013, 04:02 PM
By LoveLearn in forum General ElectronicsReplies: 12Last Post: 24-05-2013, 11:41 PM
By D-man in forum Projects, Jobs & RequestsReplies: 0Last Post: 08-04-2013, 09:06 AM
By LoveLearn in forum New Member IntroductionsReplies: 2Last Post: 25-01-2012, 07:46 PM
By 7AxisCNC in forum Manufacturer NewsReplies: 0Last Post: 17-05-2011, 01:04 PM