I had my spindle running at 3500rpm and it was seriously heating up. Tried all the usual things, preload lubricant etc but to no avail. Thread on it here:

http://www.mycncuk.com/forums/showth...2074#post22074

Long story short I have rebuilt the spindle with better bearings and different seal system.

Rubber seal replaced with alu labyrinth (shaft clearance 0.0015")


Click image for larger version.  Name: 009-1.jpg  Views: 615  Size: 144.8 KB  ID: 4060

I have also made a perspex guard over the pulleys. It is smoked rather than black so you can see which pulley has the belt on

Click image for larger version.  Name: 005-2.jpg  Views: 590  Size: 161.8 KB  ID: 4061

without guard

Click image for larger version.  Name: 007-1.jpg  Views: 617  Size: 201.0 KB  ID: 4062

I am running the bearings in and will post progress when I next get a chance