"PrecisionmachinisT" wrote in message
news5CdnVRc85SyKfXMnZ2dnUVZ_jKdnZ2d@scnresearch. com...

"Terry Coombs" wrote in message
...

Almost finished with the part ... OK , what this part is , it's a sleeve
that goes on a motor that runs an oilless compressor . This sleeve needs
to
be press fit on the motor shaft as it transmits all the torque to the
crankpin . The crankpin has a taper that fits into a half-dovetail cut
into
the sleeve , as the nut is tightened the dovetail locks the crankpin to
the
sleeve/shaft .
I currently have it machined for a .0015 interference fit ~ .700" shaft
diameter. The outside has to be a hand-press fit into a roller bearing
and
the crank plate that mates the shaft to the crankpin . NOW , the question
is
how much is this sleeve going to grow when we press it on ? Do I allow for
that much growth , or less ? Once installed on the motor shaft it's going
to
be difficult to turn it down if I get it wrong ... and right now I have
exactly the fit I want in the bearing .This would sure be easier if there
were holes for centers drilled into the shaft
--
Snag
My gut tells me to take the OD
down that thou-and-a-half ...


You're probably wasting your time, and it'll throw another rod before you
even get another 10 hours of run -time...**** poor design engineering.

Been there done it. Still got an old tank to prove it.

--


My neighbor's unit and this ain't the first time . The "press fit" sleeve
the last guy made had over .015" clearance on the motor shaft . I agree the
design leaves a lot to be desired . I also have an oilless on a wheeled 20
gal tank , and when it dies it goes - but I will keep the tank for
additional storage for the shop compressor.
--
Snag