[cncmadness]

I have got the motor and controller set form cncrouterparts.com that include 4 motors and the gecko 540 controller. I have been running the machine for about 6 months now and I keep having one of the motors on the slaved Y axis lose some steps. After running the machine for a bit I have to check with a square to make sure it is still lined up. Most of the time I have to unpair the motors and move one of them to get it back in line. My gantry is 24 inches long and after about 2-3 hours of running I notice that the one side will be out about 1/8 - 1/4 inch from the other side. I am looking for suggestions how how to correct this. Could it be the motor, controller, or software. I'm not sure where to start my search. Please let me know if there is any other info that one would require to help fix this. Pictures below. I have the forward and back motion as the Y axis. The gab that I measure is when I place the square in the right corner or the gantry and the side rail. Thanks in advance for any help.

[ger21]

It's unlikely to be the motors, or a software problem. Make sure the G540 has adequate cooling, as overheating can cause this.
Also, make sure there's no binding causing it. You may also need to reduce your acceleration settings.

[cncmadness]

I have found videos about using the posts to tune the motor. Is this something that would help?

[cncmadness]

I have been playing around with no success. I have slowed the ramp up speed as suggested and I am still having the same problem. I did find a loose pulley, but even after fixing this, its still happening. Does anyone have any other suggestions on what to look for. What is considered to be hot for the motors, and what is the best way to keep them cool. Is a fan enough to do the job, or should I be placing heat sinks on them. I also could not find any binding

Thanks

[aarggh]

Looking at the fairly large design, but somewhat narrow rails/beams, I would hazard you have some "racking" occurring.

It only needs a couple of thou of give at any point to have this magnified at other points, causing missed steps under load.

Try slowing the speed down, and maybe bracing temporarily while testing, such as along the front at the top, to see if that makes any difference.

cheers, Ian

[cncmadness]

are you able to explain what you mean by racking a bit more and where you would suggest adding more bracing. Are you talking about the rails on the sides or the gantry that are small. I know that even if the rails arent stright on the sides that this shouldn't be a problem as the gantry is only held in place on one side and the other side is floating with only one set of bearing which hold it up.