Well, 53 to be exact.
I've been looking around to collect Mendel parts for a little while, intending to reproduce from my BfB Darwin. I've picked up four nema17 steppers, built myself some stepper drivers and electronics, and I'm now looking for the mechanical parts. On the parts lists are a significant number of bearings, which can be quite pricey.
Luckily, I found RepRapKit.com, based in the UK, and ordered myself a complete set of bearings for less than 20 quid - much cheaper than everywhere else I've looked so far. Excellent service - I had a couple of emails with him and he seems like a really nice friendly chap. Parts were ordered and dispatched quickly, and delivered next day. I got 51 smaller bearings and two M8/skate bearings (including enough to make a geared/stepper extruder), they all look good and turn well. The store is selling ABS and bearings so far, and is looking to expand into extruders and other RepRap bits.
I also got round to blowing the dust off my BfB Darwin. It needs several bolts tightening and some general maintenance, and I disassembled the three stepper motors, covered them in plastic bags and tape, and ground out some proper flattened shafts using my dremmel. Note : metal filings from filing or grinding are not good inside a precision engineered bearing, and since they're highly magnetic, it does tend to attract the dust.
Make sure the bearings and motors are nicely covered (with blutack/tape/plastic bags) otherwise the dirty bearings will seize or grind away very quickly.
I'd had a go at filing the shafts back during the initial assembly, but didn't have the right tools - I did have a few problems with the axes slipping at times. Once it's all back together, it should be fine this time.