Bill Freeman wrote:

Paul,

I'll have to be #3 on the "Yikes, the blades are held on
with snap rings?!" crew.  Call me chicken, but I'd be
a lot happier with a screwed-on bearing retainer.

I'd suggest a design which has the hub threaded on the
outside and an external nut/bearing retainer, with some
sort of a safety locking system (bend-over tabs, safety
wired tabs, whatever).

I just get visions of some sort of weird resonant vibration
bouncing the snap ring, or a rock flying up a banging it -
admittedly EXTREMELY unlikely. Your design is fine on
paper but scares some of the more cowardly the customers.

Wait - here's an idea.

How about an aluminum retainer machined to just clear the
snap ring on the inside (towards the blade) surface, which
would be slipped in and held by a couple of cotterpins.  The
idea is to positively preclude the snap ring from moving
radially inward, plus cover it up to protect it.  If a snuggly
fitted retainer guarantees the ring position, then is should be
fine.  Watch the internal corner radius on the groove, say
at least .010" for stress concentration reasons.

Bill

Yes on that retainer. That is what I meant about the sleeve.
the sleeve could be held in by the jam nut I am thinking of using
to lock the blade and index it.

There is at least one design around that uses snap rings.

Paul Lamar
 
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