spindle cross section view

[Ross77]

Thanks, I was struggling to find info as well, thats why I have gone to the manufactures.

It's in Chinese, but the bits your can read suggest:
220v, 400Hz, 3.7Kw, 12.9A, (fairly powerful then), 24000rpm, 0.003mm spindle runout, 16mm collet (?) with 0.02mm runout (? not sure), and some figures which might be bearing preload (190+-10N and 150+-10N). Please correct me if I'm wrong!

I think point 2 is holding the inner races to the shaft and point 3 is the preload,

You can see opposing pairs of angular contacts top and bottom

Thats the bit thats confusing me as there are plenty of designs like that but the manufactures say dont do it. The locked bearings should be at the bussiness end and free floating bearing at the other,



http://www.skf.com/portal/skf/home/p...ewlink=9_0_51b


still a little knowlege being a dangerous thing and all I'd better do some more research
I guess there are always compromises with any design and you just have to get it to suit your application

[coredump]

Thats the bit thats confusing me as there are plenty of designs like that but the manufactures say dont do it. The locked bearings should be at the bussiness end and free floating bearing at the other,

Deckel do the opposite: free floating (needle bearing) at the nose, locked bearings (dual andular ones) at the end. This allow very sturdy spindle with a short distance between nose and bearing (almost 0 since the needle bearing is outside the taper nose).

[Jonathan]

Deckel do the opposite: free floating (needle bearing) at the nose, locked bearings (dual andular ones) at the end. This allow very sturdy spindle with a short distance between nose and bearing (almost 0 since the needle bearing is outside the taper nose).

I might be being pedantic, but surely as the spindle heats up the shaft will expand and push the cutter down slightly further. Clearly won't happen if the fixed bearing is near the chuck. Negligible?