Machining a disk that wont explode on it's 1st run ;)

[Dan-27]

I've begun to machine my tool steel disk and I've got a question. Do you think I should run it on 25id or 30id needle roller bearings?

At the moment the shaft is 29.95mm dia

I think the plan is to have the needle bearings in an Ali sleeve. I know TS2 ran the needle bearing directly in the nylon and he said the bearings got mangled.

Any suggestions welcome.

To clarify:

White = Blade and shaft
Purple = Bearing
Silver = Ali sleeve
Dotted line = where the bulk heads will run to

Teeth are 15mm but I may make them 10mm. Looking to run it around 6,000 rpm.