Chuck, question about building Dudley

skyguynca

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In our and others discussion about Dudley, you uses a combination of 1/4 nutplates and bolts or solid rivets.

First was 1/4-28 the bolt size? What size were the AN470 rivets?

Were solid rivets used on the tube cluster plates? Spacing?

Were 1/4-28 used where you could not buck solid rivets only on the cluster plates? What was the bolt Spacing?

Thanks Chuck

David M
San Jose CA
 

C. Beaty

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It’s been a long time ago, David. I think Dudley was a name I jokenly applied to the 1st gyro I built after my partner decided to go to law school; that was probably 1968 or 1969. If so, it did not use any rivets, it was built from 2.5” x 0.120” 2024 round tube and used gang nut plates on both cluster plates and cheek plates; ¼” x 28 pitch.


Because it was not riveted, I was able to break it apart, build a crate and ship it to Rialto, CA for the PRA 1972 flyin where it won Man & Machine award, mainly because no one there believed Hughes helicopter blades would work on a gyro. I let everyone who wanted to fly my Hughes OH-6* blades, beginning with Ken Brock. Everyone was amazed at how much cooler their Mac ran when flying Hughes blades. It was a bit of a chore, hand starting those blades, but there was plenty of muscle available.


Later gyros, using 3” x .065” wall tube used 1/8” solid rivets at cluster plates; rendering mast and keel inseparable.


*Hughes OH-6 blades are the same as Hughes 500. I bought a truck load of these blades (runout or pulled for one reason or another) from the Army training school at Ft Rucker. Same profile and chord as 269 blades. The Army later began chopping helicopter blades to prevent their reuse.
 

skyguynca

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Sorry Chuck, Dudley was the name given to your 3" x .065 tube gyro. We had discussed alot about it and I was even given a set of your drawings. However I never asked about the bolts and rivets.

From the napkin drawings is looks like you used 1/4-28 bolts for attaching brackets and the head/mast cluster plates but look like rivets for the other cluster plate. So I was wondering if you used 1/2 or 1" spacing on the rivets and if it was larger spacing for the 1/4 bolts.

Also we did discuss the round tube 2.5x.120 2024 tubing and the nut plates use on it. I had asked you if 6061T6 would work at 2 1/4 x .120 was safe and you had said for a 500# should be fine. That the 2.5 2024 use was because you had it laying around.

It seems from all you guys who have refined and expanded our knowledge on gyros and helicopters, both in design and understanding how and why it works.......built a lot of flying machines from "stuff you had laying around".

Thanks for the information the other day on the use of the 269 rotor blades. I known you had done a drag test/hp use on them but could not find it again. I am glad to know that they are as good as any blades for gyros produced today.

I know it was a long time ago, but thanks so much for the info, you are a diamond Chuck.

David M.
San Jose, CA
 
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