Reprap Prusa i2
Linear bearings arrived; frame and axes complete
The long-awaited LM8UU linear bearings finally arrived this morning. Here’s the proof:
With the 40mm M3 bolts for joining the top and bottom print plates also arriving, I was able to complete the frame and axes build this evening. I couldn’t find a lighter to soften the plastic bearing retaining clips as has been suggested on various sites and a couple of them unsurprisingly broke during fitting. Thankfully, they seemed to respond well to a spot of Plastic Weld and all of the axes slid onto their respective smooth rods without issue.
I was going to screw the Y-axis bearing holders onto the lower print plate as the holders have tabs for this but, after marking them out and double checking the hole alignment, I figured it would probably be easier to just glue them on as recommended in the Prusa v2 build instructions for the PLA bearings. So, with the Araldite mixed and applied to the holders, I positioned the bottom plate, wiggled it around a bit, checked alignment on both ends and left it to dry.
The X-axis went onto the rails and runs very smoothly. The Z-axis was more tricky because the vertical rods need fine-tuning to get things running smoothly. I seem to have it reasonably smooth but it isn’t as good as the other two. The whole assembly is quite heavy, however, and a cursory test indicates that gravity picks up where alignment falls short. Worst case, I’ll have to make further adjustments during actual print testing if there are problems.
I’ve put the Z-axis threaded rods in place for now but they’ll come out again when I get the stepper motors. And there’s really nothing else I can do now, until pay day (which can’t come soon enough!). Here’s a few photos of the finished frame and axes:
Posted on 19 October 2012
