14-13 Aeromatic spinner

Dan Cullman

Dan Cullman

New member
Thanks, Bob for an excellent newsletter. The Aeromatic spinner drawing is excellent. However, it brings out one flaw in this assembly. If you'll look at the backplate drawing, you will see that it calls for a heat treat after forming. This makes this part too hard to withstand stress and almost every backplate that has been in operation for any time has a circular crack around the circumference of the Franklin flange. The problem is that there is no front of the hub support for the spinner. Aerodynamic forces push on the spinner, causing the backplate to flex. The centering shaft does center the spinner; but does not support. I have repaired several of these backplates with a circular doubler made of .040 5052H32. You can use the same attach bolts. Dan
 
Thank you, Dan:

I have forwarded your comments to editor Cy Galley, who is responsible for putting the drawing and comments together for B-C Contact!

While I have your attention, will you be coming down to Sun 'n Fun?
 
I have a spinner on my 14-13-2 that had a crack around the crank flange. I sandwiched it with disk on both sides but I probably don't have enough time to prove it it s long time fix.

I obtained a front bulkhead spinner from a wreck. It was cone shaped and fastened under the front plate. Looked like it would work well, but it was so badly crushed, I think I re-cycled it.

Cy
 
That fix will work for a long time. I did the same thing when I adapted the spinner for the McCauley CSP on the 6A-335. I made my own front support 'cone' out of fiberglas. It made a true running firmly supported unit. Dan
 
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