11 Aug 2012

Welded the hub adaptor onto the flywheel. I lined it up by eye, using the six bolt-holes that were just visible inside as a guide, and spot-welded inside to get it to stick. Then went round the outside: there was a lip with a 2mm gap all the way round. Once I'd done that, I realised that I'd made a serious mistake spot-welding the inside, because, damnit, that's where the tapered bush fits! So I then had to spend an hour with a drill (breaking 1 and re-grinding 3, continuously) because of course the grinder won't fit getting out three blobs of metal. In the end I actually ground off the last remaining bit off the taperered bush. Then when it came to fixing the taper-lock bush into the adaptor (holes marked in green) I couldn't find the hex-bolts! It's all go, here...

Showing the adaptor plate attached to the motor, finally. Found some 3/8-16 bolts (yay!). Actually cutting out the adaptor plate was a bit of a sod. Whilst the outside was fine, the inside was hell to do with only an angle-grinder. But that was nothing compared to drilling the holes. I started with a 3.3mm, snapped that. Then used the 3.0mm, made 2 guide holes and snapped that. Then got the 3.5mm and managed to complete the remaining holes without snapping it. Then started with the 6.0mm, widening the holes. It took eight minutes per hole (there's 9 of them). I sat there with a squirty garden water bottle, over the top of the drill, with ear-defenders on, pushing down on top of the drill and watching the pretty patterns of water and bits of metal jump up and down on the plate as it screeched and resonated the entire plate. Oh - then I had to do the 12mm holes, which took another six to eight minutes each. That was when the fun started. Holes 1 and 2 were fine, but hole 3 is when the drill jammed, yanked out of my hand (it was on "lock" so was still running), wrapped the cord around itself a couple of times, pulled the metal plate off the toolbox, smashing it against my leg, tripped the fuse on the extension cord and also managed to pull the plug out of the socket as well. Oh, and snapped the 12mm drill-bit.

So, after that, I was a bit more careful. I re-ground the drill-bit with the angle-grinder, then got rid of the burrs on the underside hole: they were actually protruding out a good 8mm, not in a spiral as you'd imagine, but as a complete unit! It was as if I'd managed to push the hole to project out of the plate. So the next few holes i left 1mm or so and then ground off the burrs and then drilled from the opposite side for a bit.

The motor bolt-holes were also a bit of fun, because I'd bought an 8mm drill-bit when I actually needed a 3/8in drill-bit (8.8mm). So, that had to involve rotating the drill to cut off the top and bottom edges, then move it sideways in the hole, using the very last section of the drill bit closest to the chuck to get the last bits out. All a bit messy but it worked.

Just a reminder photo of where this is all going. I should have the holes in the right place, but there is a little bit of play in those 12mm holes in order to adjust things. The absolute most important thing is that the clutch plate is properly lined up with the clutch housing, so that when the clutch is engaged it's all centred. If the clutch is clamped off-centre then it'll destroy the clutch-plate as the whole thing judders itself into oblivion! All good clean fun...