Hi Mark just read all the thread
hahaha!!! that must have took some doing :)
i dont have any heat trouble with the larger two motors, its the tiny 4000kv spindle thats giving the bearings im using a hard time m250cnc(phil) thinks it may help if i run them in bit by bit not alowing them to over heat or trying lighter grease, ill give those a try when i find the time

thank god somone has a rc brushless motor spindle working for them, loads of people seem to have a go at building them but iv had no reports of any useful results untill yours, are you running it 1:1 or are you on pullys and belts??