prop speed reducer made on a 3-in-1

Very nice! Thanks for sharing this, Ted.

Outstanding job, Ted. I'm particularly impressed with your clever extension of the compound to make possible the machining of the large pulley. Amazing what a little creativity can do!

You made a very good decision to avoid a form tool for the grooves, which would have led to nothing but grief on a small machine. Did you find much chatter in turning such a large diameter?

Harold

Nice looking PSRU, Will you anodize it to harden the grooves?? what type V-belts ? regular automotive, special construction ?? Tension adjustment ? or idler pulley. Does circlip take prop thrust.??----Jerry

Good Job Ted ! Safe and sure on stuff like that.

martin

Hey Ted,

Very ingenious. And nice work.

About the prop set-up though, I don't see anything to keep the prop thrust from walking everything off.

Take care.

Brian Laws>This shows the making of a propellor drive speed reduction that *really*

Ted,

Very nice work. Goes to show you what can be done with a little thought.

Jim (greeeeeeen with envy)

Yes if I got a bit to aggresive in the cut depth or feed rate. I have an independent power feed on the long axis (electric dc motor) so I can vary the feed rate even while cutting. I just increased feed and depth of cut 'til I got a bit of chatter then backed off a little. Since this got sorted out very early in the process, no chatter marks appear on the finished piece.

Ted

That will be up to Ray. I doubt it since the a/c will not likely see hundreds of hours.

3VX belts. See pgs 2285 et seq. in MH 24ed. The X signifies notched cross section. This improves flexibility for wrap on small pulley sizes and improves grip.

In the photo "The complete reduction drive with test prop", look behind (to the right of) the axle mounting blocks. You will see the four bolts that fasten the engine to the aluminum plate. There are some washers between the bolt heads and the plate. One or more of these can be removed and placed between the aluminum plate and the engine thus lowering the engine and increasing belt tension. A PITA to adjust but very unlikley to slip in service. :-) Given the performance of modern belts, need for adjustment should be very rare.

See reply to Brian Lawson.

Ted

Thank you. It was fun.

Look at the picture "Axle assembly. Note circlip behind left block". Both blocks are slit from one side to a little past the opposite side of the hole for the axle. The axle is a snug sliding fit in the blocks with the bolts loose. These blocks are bolted to the engine mounting plate and are squeezed tight to the axle by one of the mounting bolts on each block. In addition, there is a circlip on the axle just behind the forward (left in the picture) block. Talk about belt and suspenders, I figure that any of the three could handle the expected 250lbs thrust.

Ted

Just as I expected, Ted, and an excellent solution. Very cool!

Harold