In article 1133388294.822423.141800
@g47g2000cwa.googlegroups.com,
says...
Wow! Thanks for that Ned. So a collar with a mere 5/16" bolt
potentially will hold 3000lbs. This is a medium duty machine so I think
that's good enough. Oh wait, what about knurling the shaft where the
collar is positioned? I would guess that it would definitely improve
the "bite"... right? it's easier than cutting into the shaft.. and in
the end.. it's better for something to give a little instead of snap
and fly I suppose.

ok, Compare a mounted roller bearing and a mounted ball bearing. The
dynamic load capacity is pretty much 2 to 1 in favor of the roller
bearing. Information from mcmaster.

You should be aware that those ratings are for radial
loads. Mounted ball bearings (flange & pillow blocks, etc)
are generally not recommended for axial (thrust) loads, and
the axial load rating for mounted roller bearings is
substantially less than the radial rating.


I'm using flange mounted ball bearings and they have a 7200 lbs.
dynamic load capacity. there will be six total working against the same
load and this machine's tension force is by a hand operated screw
leveraged by a sliding 36" or so handle. maybe less. The double set
screw in each bearing is also somewhat needed to keep the shaft from
moving in this situation. BUT... question:

How are you sharing the load? It's quite difficult to do
this reliably for bearings on a single shaft.


Do you think it would hinder the proper function of the ball bearing if
there were press fit bronze sleeves contacting the shaft where it
passes through the heavy plate that the bearings are attached to?? my
theory is that the bronze bearing will take some of the stress from the
load perpindicular to the shaft which is on the end, between the collar
and threaded end. flawed?

If I understand, I don't think this will help. Even if you
got the two bearings mounted such that they were load
sharing, which may or may not be possible, the load
carrying capability of a bronze bushing is insignificant
compared to that of a ball or roller bearing.

It would be easier to be helpful if you were to give more
information on what you're trying to accomplish.

Ned Simmons