Using RC Brushless motors as spindle

[Jonathan]

personaly (because im lazy) i would mask of the section where the A/C bearing is going and wet n dry the rest down on the lathe to a more convenient diameter (im assuming your collet shaft is your cheapest part)
if thats a double row A/C bearing you wont need any pre-load on it

i thought you were going to make your bearing housing 43mm ?

It did occur to me to do what you said with the wet and dry, the problem is that will surely increase runout since all the other bearings will locate on an uneven surface.
It is double row, but I think it needs to be fixed onto the shaft somehow to stop it creeping.

Yes I was going to make it 43mm, to fit with Kress spindle - however I'm now going to buy Chinese 80mm spindle instead so etc. I may make it less anyway as annoyingly the smallest aluminum bar I have in stock is 3".

I've been reading up on heating bearings to make them fit. I think it should work for the angular contact bearing but I'm not sure about the others since they're housed in aluminum with laminated steel around that which will all expand at different rates.

[blackburn mark]

It is double row

good move in my opinion :) my double row was a press fit i havn't used locktite on it yet, i did intend to when id tried it and all looked well, its done some hard work so far and iv had no issues with it, i do get a kind of harmonic ripple in the finish when i use a fly cutter in aluminium but it performs way above my exspectations and the ripple may be being caused elswhere ? (gantry sides maybe)

80mm spindle

ah, with you now :)

i'd be shit scared of getting the shaft stuck only half way home using heat... that shaft will soak the heat out of those tiny inner bearing races in no time

i would think that runout issues of bearing misalighnment (im pretty sure you will get some no matter how hard you try) would be massive compared to any runout you get with the wet n dry inaccuracies
the advantage in my opinion to the microscopic missalighnment you will "probably" get is that it will pre load all your bearings to some extent and stop any of them free wheeling and skidding
However........ im no exspert and only guesstimating with this stuff :)

skim a tad off between the bearing seats

nice