After having backlash problems on my RepRap Mendel X-axis and getting sick of the awkward round-4-corners belt path, I decided to give it a re-design, in the hope of shortening the belt to take up some slack while simplifying the construction.
These brackets make the belt-path compatible with carriages intended for Prusa Mendel. I have included an adapter bracket that allows it to still be used with the original Mendel X-Carriage when necessary, however the idler bearing and pulley need to be spaced quite far out from the plastic parts in order to keep the belt parallel to the X-axis, with a full nut and a washer or two in the case of the bearing.
I hope someone will design something like the OpenX Carriage (http://www.thingiverse.com/thing:6278) but compatible with this, so that a 624-bearing-based carriage can be used with the Prusa-style belt-path, that is if I don't design one first.
I have also included an optional second idler bearing bracket to go directly next to the motor bracket, so that the belt turns slightly less of a sharp angle as it goes round the pulley, hopefully reducing belt wear, though I really don't think it's necessary.
The big circular holes in the motor & idler2 brackets are there to allow ventilation around the X-motor, so that PLA parts don't heat up too much. (I wanted test parts to be biodegradeable in case I messed up)
N.B. I have updated the files for the main brackets at either end as I found a couple of weaknesses in my first prototypes where I cut away excess corner material too liberally and found that the slots for m3 captive nuts shrank more than I thought they would, making it difficult to fit them. They should also be easier to print now.
The idler is designed such that you should be able to fit the belt in whatever clamps you want easily, then adjust the tension by pulling the bearing back before tightening the nut(s) securing it.
By using this as opposed to http://reprap.org/wiki/Mendel_Alternate_X_Motor_Bracket you will save:
4x 624 Bearings
4x M4x15/20 Bolts
4x M4 Nylock Nuts
12x M3x20/25 Bolts
12x M3 Nylock Nuts
and associated washers
While using an additional:
1x 608 Bearing
3x M8 Washers
2-3x M8 Full Nuts
2x M8 Mudguard/Penny Washers (or a printed pulley)
7x M3x10 Bolt
8x M3 Full Nut (All 8 bolts & captive nuts are not strictly necessary)
and if you use the adapter for the original x-carriage:
Replace 4x M4x40 bolts each with 1 washer and full nut with -
2-4x M4x35 bolts + washers & full nuts (all 4 not necessary)
4x M4x25/30 bolts
4x M4 Nylock Nuts
8x M4 Washers