Designing a Metal milling bushless Spindle

[Kevman]

@ Ross, im using 2 12mm ID AC bearings up front, Nachi #7201B i think they were. Rear is a 12mm radial bearing.

well, on the preload issue, i've got the bearing pocket slightly undersized in depth & im using a shim between the bearings. preload is by tightening down on the bearing retainer cover. its not very high tech, but i figure im going to run this as is & see how long it lasts. not very scientific i know.

as to the Heat dissapation, ive got one big vent hole to draw in air on the front of the square block with 4 smaller vent holes on the top of the block, where the motor mounts. the square block will bolt into the Z-axis moving plate with 4 bolts.

one thing im worried about is the weight. its at 5kg already, i designed my z axis on 4 THK RSR 9WN's...

[Ross77]

@ Ross, im using 2 12mm ID AC bearings up front, Nachi #7201B i think they were. Rear is a 12mm radial bearing.

well, on the preload issue, i've got the bearing pocket slightly undersized in depth & im using a shim between the bearings. preload is by tightening down on the bearing retainer cover. its not very high tech, but i figure im going to run this as is & see how long it lasts. not very scientific i know.

as to the Heat dissapation, ive got one big vent hole to draw in air on the front of the square block with 4 smaller vent holes on the top of the block, where the motor mounts. the square block will bolt into the Z-axis moving plate with 4 bolts.

one thing im worried about is the weight. its at 5kg already, i designed my z axis on 4 THK RSR 9WN's...

That's the best way to do the pre-load. Most of the high end ones are done that way as it keeps the pressure equal, the draw back is that it is not easy to adjust.