I got the hub back today Paul.

When will the dimension drawings be available?

Tell Frank I will spring for the $250 if you will handle the sales

Milo

Jim Rudholm found some heat sink surplus and much cheaper. I called them and they have 175 in stock. The size is enough
for 3 heat sinks. The cost  for 3 would be  $25.

Here are the PSRU dwgs.

It would be better if I sent you an IGES or DXF.
What dwg program are you using? The dims are in the IGES or DXF files.

Paul Lamar

These alloy steel screws are 135,000 PSI and the diameter at the root of the thread is at least .2 inches. So the area is 0.031. Times 10 for ten screws is .31 square inches. Times 135,000 PSI = 42,000 pounds shear.

The bolt circle radius is roughly 1 inch so that is
42,000 inch pounds of torque in theory. Divided by 12 for foot pounds
or 3490 foot pounds.


The prop torque is 3.17 times 200 foot pounds engine torque or 635 at the engine torque peak.

That is a factor of safety of 5.5 in theory.

Putting it another way the stress on the bolts is 24,000 PSI in theory.
They should be inspected for cracking at ten hours or so and then once a year there after. Or just put new ones in.


Paul Lamar

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