Just finished my Lead 1515 and went through testing the motor hogging. Z and Y jog continuously and smoothly. X motor will only jog in .1" increments and at 1" increments it starts and then doesn't jog. It does the same under continuous jog setting. I've triple checked wiring and verified the gold tension nut is good. I detached the x motor from the gantry and it jogs without issue when not connected to the flexible coupler. Is the threaded rod causing the lock up?
Its either electrical - see docs:blackbox:faq-identify-motor-coils [OpenBuilds Documentation] Or mechanical (can you spin the leadscrew by hand?) - in which case taking the axis apart and checking what is binding is the next step
I'll check the wiring again but I'm confident it's not that. All the motors are wired identical and all work except this one. I can rotate the leads crew by hand but not as easily as I can both y motor lead screws. Is there an easy way to remove the z gantry to troubleshoot? I'd like to avoid hours of taking apart the x gantry
Actually now that I think about it, it can't be electrical. It functions perfectly when not connected to lead screw. I'm guessing the lead screw didn't thread properly through the z gantry assembly or the eccentric screws aren't allowing proper wheel contact with C channel
Understood. I will disconnect the 4 wires at each connection, blow them out and reconnect. Fingers crossed that fixes it. Eager to get this thing up and operational
Before that. Just feel the motor. Light grip on shaft, is it torque-y or stalls super easy? Process of elimination...
I'm assuming the shift being the 1" section from the motor or did you mean the lead screw? When I removed the motor to test its rotation I did grab the 1" stub and it continued to rotate with me trying to add resistance (which is why I'm thinking it's a lead screw / z gantry plate issue). I'll try it again tonight and if it spins free regardless of my trying to resist the motor, I'll assume the wiring connection to the motor is fine and it's a binding issue withing the z gantry assembly
Good, with the extra information, we can put wiring to bed then. Not that. If you couldn't stall it easily, its got torque, and the wiring is fine. Onward with the mechanical then - tear down and see if you missed something (spacers under leadnuts?) or overtightened something (eccentrics), forgot a bearing (end plates), have an extra tight leadnut (run leadscrew up and down in it a couple times to bed it in)
I remember having a little bit of resistance getting the x lead screw fed through the small threaded recatungalr box. I assumed it just needed to break itself in and maybe the thread was molded wrong (or slightly off). It took me longer to hand thread that lead screw through. Could I have a bust in that small piece? My theory is that if that was the issue that the metal lead screw would create a new thread in the plastic material and problem solved but maybe I'm wrong about that. The other thing I noticed was a couple of the wheels (3 of the 16 on that z gantry assembly) weren't tightening with the eccentric screws no Mattar what I did. Could that lack of wheel contact cause the motor rotation issue?
It wouldnt cause binding no, but do address it. Loosen screws on the fixed side, push wheel over towards the extrusion, and hold in place while tightening, then adjust the eccentrics. If the wheels on the fixed side are too far out, the eccentrics cannot reach. This is OpenBuilds parts right? or bought from a 3rd party (in which case the hole spacing may be wrong instead) Our leadnuts are cut, not molded. Or, if you had a molded one, is this Openbuilds parts, or 3rd party?
I will try and isolate the issue with the instruction you have given. I believe the bind is happening where the lead screw goes through the z gantry assembly. I will post a video when I get home and maybe that will provide some clarity on the issue
Nut blocks are often a bit stiff when new - lubricate the leadscrew with a dry spray (ptfe or silicone) and use a battery drill to grip the leadscrew and run it back and forth several times (obviously with it disconnected from the stepper). As @Peter Van Der Walt has suggested, check that the leadscrew is aligned in a straight line with the bearings at each end. Alex.
When I built my machine I ran the lead screw through both the nut blocks while they were still un-tightened. I then gradually nipped up the screws, tapping the blocks gently with a spanner or something to "nudge" them into alignment while gradually taking up the screws and checking the leadscrew was still free. You can do the same even though your machine is built - just slacken the nut block screws and do the same as above.
I'm having the same issue. The X axis and one of the Y axis lead screws where extremely difficult to thread through the nut blocks. And now that it's all hooked up the X axis does not jog at all only at .01 increments and can't continuously jog on the Y without one side giving up and the system kinks itself to one side. Would new nut blocks on the gantrys help my situation? Because the lead screw is the only thing I can think of that is causing this.
Also see docs:blackbox:faq-identify-motor-coils [OpenBuilds Documentation] Test the motors off machine and see if they move erratically
Yes, the nut block should thread on smoothly with very little friction. Some people have success using a drill, chuck the rod and spin it through the nut a few times. If this is still tight contact the parts store, if it has the anti backlash feature make sure the backlash screw is not causing the binding. And dry ptfe lube helps. Cheers Gary
Then that has to be the issue. I tested the motors off of the machine like Peter suggested and they all spin normally. I even went ahead and switched the motors around(and made sure all wiring is up correct) and now the 2 motors I am having issues with happen to be attached the to lead screws I had a tough time threading. I'll just have to order some new nut blocks and switch them out because that's the only logical thing i can think of. And i didn't think of the drill because I didn't know if it could have damaged the lead screw. Wish I would have because the blisters weren't pleasant lol.
Definitely try lubricating the leadscrew (dry ptfe or silicone spray ONLY) and running the leadscrew back and forth several times with a portable drill - this is a fairly common problem and nut blocks are often a bit stiff when new. Alex.
It's actually an advantage to have the nut blocks tight initially - using the drill method above will bed the Lead-screw thread perfectly to the block and almost certainly give a nice smooth fit. It wouldn't be much use if the blocks had floppy threads in them straight from the factory.
Also, make sure you aren't overtightening the nut blocks to the gantry plate, and when you adjust them, tighten one to the plate, gently squeeze them together and tighten the second - the aim is to have each nut block touching either side of the thread but not gripping it tightly. Alex.
Thank you for the advice. The Silcone lubricant was exactly what I needed. Couple passes through and it was easy to turn it with my fingers. Machine is up and running now.
