Z axis Stuck

So I'm ready to print, I just have to fiddle around with the software, and now my Z-axis wont move via the belt. The motor works, and all of the threaded rods moved freely when the stage was not placed on top of them. Heres a list of causes that I have looked at and I think that I have okayed:

* The locking nuts that surround the corner bracket are not locked to the corner bracket
* The Bed Corner rotates freely, and there are not backlash springs.
* All parts that need grease are greased
* All of the bed corners are Level


I am using the pulleys from bitsfrombytes, and they are a much smaller diameter than the normal Z-pulleys. I haven't counted, but they contain close to 20 teeth, whereas the Normal z-pulleys contain around 50 or 60. My question is; Should one be able to grab the belt by hand and move the z-axis up and down? Or is there more torqued than that required? I just feel like if it were all working correctly, I should be able to move the Z-axis with my hands, just Like I can with the X and Y.

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Jay

I had something similar happen. It turned out to be bits of ground-up plastic stuck in the threads.

Ok Steve, I'll ahve a look at that and see if it fixes it. THanks

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Jay

Yes you should be able to turn the drive pulley by hand or pull the belt, everything has to align exactly. First make sure the four corners drive OK without the bed attached.

Then corner by corner bolt the bed down check movement after each bolt is done it might require a small amount of packing to ensure all stays aligned as required.

Using bigger pulleys lowers the load through the belt but does not affect the motor torque required as everything is 1 to 1 ratio.

I have found it to all be about alignment which is very important.

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Ian
[www.bitsfrombytes.com]

OK, so here is how I fixed it. The symptom was that the threaded rods would kind of wobble back and forth when the belt was turned on. This would cause them to dig into the plastic, thereby seizing up. To fix the wobble, I glued some washers to the top corner bracket which were able to support the top of the threaded rods, preventing them from wobbling.

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Jay