This shows the making of a propellor drive speed reduction that *really*
involved pushing the envelope on my Smithy 3-in-1.

http://www.metalworking.com/DropBox/Prop_speed_reducer.pdf

Ted

In article , says...
This shows the making of a propellor drive speed reduction that *really*
involved pushing the envelope on my Smithy 3-in-1.

http://www.metalworking.com/DropBox/Prop_speed_reducer.pdf

Ted



Very nice!
Thanks for sharing this, Ted.

"Ted Edwards" wrote in message
...
This shows the making of a propellor drive speed reduction that *really*
involved pushing the envelope on my Smithy 3-in-1.

http://www.metalworking.com/DropBox/Prop_speed_reducer.pdf

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

Ted Edwards wrote:

This shows the making of a propellor drive speed reduction that *really*
involved pushing the envelope on my Smithy 3-in-1.

http://www.metalworking.com/DropBox/Prop_speed_reducer.pdf

Ted

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

Ted Edwards wrote:

This shows the making of a propellor drive speed reduction that *really*
involved pushing the envelope on my Smithy 3-in-1.

http://www.metalworking.com/DropBox/Prop_speed_reducer.pdf

Ted

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

martin

--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

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 Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXXXXXX
On Thu, 05 Feb 2004 22:48:52 GMT, Ted Edwards
wrote:

This shows the making of a propellor drive speed reduction that *really*
involved pushing the envelope on my Smithy 3-in-1.

http://www.metalworking.com/DropBox/Prop_speed_reducer.pdf

Ted

Ted,

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

Jim
(greeeeeeen with envy)


On Thu, 05 Feb 2004 22:48:52 GMT, Ted Edwards
wrote:

This shows the making of a propellor drive speed reduction that *really*
involved pushing the envelope on my Smithy 3-in-1.

http://www.metalworking.com/DropBox/Prop_speed_reducer.pdf

Ted

Harold & Susan Vordos wrote:

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?

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

Jerry Wass wrote:

Nice looking PSRU, Will you anodize it to harden the grooves??

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

what type V-belts ? regular automotive, special construction ??

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.

Tension adjustment ? or idler pulley.

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.

Does circlip take prop thrust.??----Jerry

See reply to Brian Lawson.

Ted

Brian Lawson wrote:

Very ingenious. And nice work.

Thank you. It was fun.

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

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

"Ted Edwards" wrote in message
...
Harold & Susan Vordos wrote:

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?

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

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

Harold