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

**fasteddy** · 05-10-2011

Hi Karl..

At last! Someone with the same problem.. I ran a piece of code last week with 16000 lines and it was not until near the end that it stalled my x axis.. The code was making a rapid move at 45 degrees for 11mm and then stalled the x axis.. I have now spoken to several people about this problem and between us have eliminated most of the potential problems.. What remains is;

Re-install Mach3 including driver..
Trying a different PC in case it is the parallel port..

I will dive into the workshop and try both these things and report back any success/failure..

Steve..

**fasteddy** · 05-10-2011

Hi Jazz..

Just a quick mention that I am only getting this problem when the X and y are at maximum speed...

Steve..

**fasteddy** · 06-10-2011

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..

Steve..

**Gary** · 06-10-2011

at what RPM on the motors does it stall? is it at the same speed all the time? Do both motors on the X stall even if they are not linked mechanically?

**fasteddy** · 06-10-2011

It is stalling at all speeds.. Had it as low as 500mm/min up to 2500mm/min.. Acceleration from 10 - 120.. Stalls at any speed.. The x axis is completely unaffected by the z axis.. It only happens when the Y and x is both moving at full speed..

**fasteddy** · 06-10-2011

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..

Steve..

**Gary** · 06-10-2011

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?

**fasteddy** · 06-10-2011

Both motors stall simultaneously, they are using separate drivers and slaved together in Mach3.. I have tried varying the speeds and accelerations in Mach3 but that makes no difference. It only does this on full rapid, when the x and y are being moved simultaneously.. I can repeat this every time by jogging both axis at full speed, it also does it if I run code that rapids (G0) at 45 degrees...

Steve..

**Gary** · 06-10-2011

What speed are you stalling at?
What happens if you are moving X at maximum speed and then just move Z?

**fasteddy** · 06-10-2011

Have wired my nema 23 (3Nm) in parallel.. Wow, whizzes along now at nearly double the speed...!
Was re-checking this fault and had the y axis stall as well as the x..! Hmm.. seems the problem is getting worse now.. Spent a good chunk of the morning frowning hard at my PC, its a quick computer but have had some comments about the parallel port that are starting to sound ominous...!

Steve..