2 joints gantry Y axis, one motor stalls - same settings ?

Hi, I am very new to linuxcnc.

I encountered a strange problem that during jogging/test run, my 2 joint Y axis with exact same configuration for Joint _1 and Joint_2,
Joint_2 motor stalled. Joint_1 did not experience any problem. I interchanged the connections to rule out motor,driver and yes joint_2 stalls at some random point. I reduced MAX_SPEED for both joints and the problem seems to be sorted.

My question is how does this happen ? I should think the problem should affect both joints? Does stepgen favor Joint_1 ?

on a Two stepper gantry setup you shoudt consider reducing the amount of ACC
What are your numbers
can You put the INI Section here
What Machine Type is it
ARE the Cable the Same length
are the Steppers on Different Powerblocks

More info will get you to a better System

Hi, Thank you reply.
I have attached the ini and hal files.
It is not a mechanical problem as i ruled out that as whatever motor i attached as Joint_2 stalled at MAX_SPEED of 20.
I am using Chinese stuff
- Longs 1600oz steppers (big mistake, overkill as i have come to realise.) ,
- DM860A drivers.
- Linuxcnc 2.8 master.

I unhinged the gantry (no load test) Joint_1 could spin at MAX_SPEED = 20, but the same test on Joint_2 would stall at some point.
Cables are different in length by 1m.
I am running ballscrews for the both Y- axis so the motors are fixed at one end.

The hal/ini setup looks identical and you have already swapped motors so maybe
bad drive or bad parallel port?

I would swap drives and the parallel port pins in hal to see which changes the bad channel

From hal file

#ESTOP
loadrt estop_latch
addf estop-latch.0 servo-thread
net estop-loopout iocontrol.0.emc-enable-in <= estop-latch.0.ok-out

last line is that emc reference correct, just wondering

Hi! I bought 4 hbs860 driver and 1 of the motor came defective, it was too heavy when turning by hand, when it started to work it got very hot and lost the synchronism with the encoder and stall, it was disassembled and I realized that the cover where the shaft leaves was out of square then I put a piece of paper in one side to correct the square, worked like a charm.
Look at this site wiki.linuxcnc.org/cgi-bin/wiki.pl?Stepper_Drive_Timing , I used it to configure the driver on linuxcnc, in my case I used the parameters in pncconf

step time = 2500
step space = 2500
direction hold = 10000
direction setup = 5000