1 wheel not spinning z plate no matter what I do

[kec-10238]

after assembly of the z system to the rails I am not sure how tight the wheels should be. Directions say free spin but not sure what that means - how free is free? In any event I have a wheel that I'd have to tighten the concentric spacer so the concentric wheel can not spin by hand at all in order to get the spacer wheel above it to spin on the rail (it free spins fine on or off the rail). I have removed the rails, turned them upside down, alternated them and still have the same problem. Should the z system slide freely on the rails or should there be some tension? Id the z pate was assembled on the rails and you lifted it and tilted it at a 90 degree angle should the z system pretty much freefall or should it take a couple of seconds to slide down the other side? If I squeeze the ends of the rails together and retighten then it has alot of friction on the ends when sliding. If I loosen the ends so it flows with little friction then the middle portion of the rails don't allow that wheel to spin. I don't think the rails are warped as the other wheels spin so maybe this one wheel is a tad smaller than the others - unkown - it's all I can think of

[aforww]

The way I adjust my wheels is to hold the Z axis in this case and use my other hand to spin the wheels. I know it's right when it takes a bit of force to spin the wheel without the plate moving. If it's easy to spin, too loose. If it's difficult to spin, too tight.

[kec-10238]

thanks for the tension info. It may be related to another issue tho. I removed the rails and set them on my roland engraver bed (flat steel and level) and when the rails are placed side by side standing up, one of the rails is angling away from the other indicating that the end that is sitting flat on the steel plate is cut at an angle that is not perpendicular to the plate. I'm wondering if when tightened to the x & y plate. Posted pics in next post (FB link).

[Derek the Admin]

I think I follow what you are talking about. Do you mean the x wheels?There is some movement allowable in the through holes at the end plate. Loosen the tap screws.at the end plate a couple turns and it will help float it to position in range of eccentric adjustment.

[kec-10238]

been there done that - no good. I loosened all wheels, then loosened the bottom rail from both side plates. I then put wheel pressure on the top rail by turning it upside down letting the weight of the z assembly push the plate onto the inner wheels - then tightened them while putting hand pressure on it as well. Fipped it back over and adjusted (put downward pressure) on the bottom inner wheels then tightened. I then tightened the bottom rail while putting upward pressure on it (both sides and tightened. With this I was able to get all 4 inner wheels spinning on the rails. I then tightened the eccentric wheels adjusted them using opposite corners until all of them spin. I now have all 8 wheels spinning and can hand spin all eight while holding the plate. Some require more pressure to turn then others while holding the plate. The resistance seems to be the same as before when sliding the z assembly back and forth. Not sure how much tension there is supposed to be for the z plate to slide back and forth - have some resistance but fairly easy to move. I'd say about as much resistance as pushing or pulling a sliding radial arm saw while cutting wood.

[Derek the Admin]

It sounds like you have a good tension level. I would rock on with it.