What am I doing wrong?
I reflashed my firmware to define the bed size and to square up the dual endstops. So now, when I attempt to home the X-axis, as it gets to about 30mm from the stop block, it makes an sickening grinding noise and refuses to keep moving forward. All I changed was the bed size and the x2_ENDSTOP_ADJUSTMENT.
The sickening grinding noise is the stepper motor. I know is sounds horrible, but the issue is non-destructive. There are a number of reasons why your machine may be binding up, like slippage due to loose grub screws, but the only firmware reason I can think of is that you flashed with serial firmware rather than the dual version.
Thanks for the reply. I’m positive its the dual endstop version. Nevertheless, just after I posted this topic, the issue seemed to have resolved itself, I’m able to home the x-axis now. Still, I wonder what happened…
I think its is a sign, that after the refusal to go home, I drew out a 300x600mm rectangle to check for squareness, the diagonal from X1 to Y2 is 666 
I’d spend a bit more time researching the issue. Something is either slipping or binding or failing. You don’t want the issue to reappear two hours in on a four hour project. The grub screws on the pullies is the most common reason for this issue.
Yeah, I’ll keep checking.
But it’s just weird that I can move the x axis all the way to the other end and back and forth with no issues, it was only when it got close to the stop blocks that the grinding happened. I checked the belts and they seem fine.
In thinking about the video, another reason this issue can happen is an intermittent wiring issue to one of the endstop switches. In the video, it looks like one end is stopping too soon, then the other end skews a bit until it binds up and cannot move. I’ve also seen this kind of issue caused by electrical noise. There is a firmware setting that can help if it is a noise issue. If it is an endstop issue, that is kind of a good thing since your machine won’t fail during cutting.
I think it’s an issue with the squareness of my Burly gantry. Just by some quick measurements, it is really skewed. If my memory serves me correctly, tightening or loosening certain bolts in the gantry will adjust the squareness. I have to go back in the instructions for Burly.
Right now, the only thing I’m positive on the squareness is the feet screwed don to its base
Mine behaves similarly to this occasionally, when one endstop switch in the drag chain becomes unplugged at a certain position. The firmware sees the open circuit, reads the endstop as triggered and stops that motor, but not the other one. The other one tries to keep going, but it can’t, so the grinding happens. Then, it runs out of attempted movement to home, and the machine stops with “homing failed.” Because it’s an intermittent failure, it only happens sometimes. Generally, I can just move the gantry a little, and try again.
The DuPont connectors flex just a little too much in the drag chain, or at least that one set does. I am going to get around to re-wiring the whole machine so that there are no connectors within the constraints of the drag chan. At some point. When I get around to it.
First take the belts off the motors and put tape on the motor pulleys so you can flag them and see the spin direction. Then issue home command, verify the spin direction is moving and correct, and manually push and hold each endstop. If all that is fine, I would suspect intermittent or broken wiring (same sound mine was having before realizing I had single conductor and not multi stranded so it eventually broke)
Robert,
On someone else’s topic, you mentioned the noise issue and mentioned a noise threshold setting in the firmware. I tried that, but it didn’t work for me. But it got me thinking, so I decided to inspect the wiring. I had extended the limit switch wires with dupont connectors. I’m not afraid to admit that one of my crimps was a bit sketchy. So I recrimped the wires and it worked…no more grinding and homing the X-axis is working as it should.
Thanks!!!
So… Basically the same problem as I described, different cause. XD