Summary

This is a linear bearing holder for use in the Ultimaker's axis drive system. This will replace the stock wooden blocks that only hold brass bearings. It will also clamp a drive belt and hold one end of a 6mm axis rod. I combined Gijs's belt tensioner(http://www.thingiverse.com/thing:19892) with this linear bearing holder. I modified Gijs belt tensioner to give it a sharper curve and merged it with this holder combo.

Instructions

  The linear bearing to use is a LM8UU 8mm linear bearing.  It can be purchased on ebay.  Linear bearing installation can be a tight fit.  I had to use a rubber mallet to pound it in.  The same applies to pushing in the 6mm axis rod into the side hole.  The belt is easy to slip into the curved clamp and will not slip when pulling the belt by hand.  Also, I'm hoping the sharper curve is enough to tension the belt as well.  So everything relies on a snug fit.  There are no screws or other parts needed to assist the holder's function.  I printed the part using natural or clear PLA at 5% infill.  It may be more brittle or weak if using solid color PLA.  So I definitely recommended using natural PLA. There are two variations of the part.  One has an extruded rectangular arm in order to trigger an end stop.  The other one doesn't.  So use the appropriate one.   Finally,  I haven't actually tested this part yet.  All I've done so far is to make sure that the linear bearing, belt, and axis rod will actually fit tightly.  It does in my case.  However, I don't actually know if it will finally fit into a stock Ultimaker overall and be durable enough to handle all the stresses in use.  Good luck.

Linear Bearing Holder Combo