Good morning Jeff
This is my own design and i keep modifying with the members
recommendations and i will go with straight big size bore 2.250"
i,dia but i am wondering about the snap ring sharp edges for materail
fatigue.
Paul is suggesting using hydraulic press to insert the plug and few set
screw,do you have an other suggestion??

Jean Prudhomme



   Good afternoon Jeff
   You probably seen my correspondance with Paul and George.
   I am designing a new prop drive reduction for the rotary engine for
   my twin project and if i do have good result i will make it
   available for others.
   I am wondering how much it will cost for you to machine one shaft
   and near futur produce a certain quantity if do have a good result
   with it.
   See the attachement for your information


   Jean Prudhomme

Jean

Yes, i have been following....I fear the part is to big for my machine.
That large tapered center bore has me spooked. You could only fit a 1"
boring bar, 10" deep, a 10 to 1 ratio is real tough especially with the
undercut taper....My machine travel is  20".  The length of the part
plus the room to feed the bar and drill well over 20".  The boring bar
has an insert that protrudes 90degrees. That reduces the clearance to
feed in and not crash the corner where the taper drops in...... I could
possibly drill out a big chunk on the VMC with a 1.5" drill..  That
would still leave the inner profile on the lathe, tight,blind and
dangerous with a crap finish because of the vibration of the long thin
boring bar no matter how many passes.That could set up stress risers
internally..
Man, I would really like to help but this part may be unmake-able as a
pure machine piece.....Is this a copy of an existing design because it
is sooooo long.......?????  Maybe somehow breaking it into 2 pieces
would be more doable.....?????

jeff



Paul
This is you had on your mind about the plug?

Jean Prudhomme

Yes but perhaps a bit shorter. Not as long.

It takes a really big lathe to make stuff like this.
I agree with Jeff. It does not need to be longer than
a Lycoming bearing shell.

I have a guy in SZP that can cut it for you.
You may have to buy a large drill.

I'll try to take some pictures of his equipment today.

Paul Lamar


Jean,   If you make the prop pilot thicker to the ID of the bore on that
end then you could chuck it up there without the chuck crushing the
pilot out of round. Leave the pilot long to mount the stock and cut it
off with the parting tool when everything else is done. Then with the
pressed in plug (same material as shaft not aluminum)  all the boring
work can be done from the open big end.  If the thicker wall were
extended to the center of the governor gear then it could be a 45 degree
transition machined by pulling up both feed handels at the same time. A
CNC lathe could do the interior taper as shown and would be a better way
to get smooth large radius fillets such as behind the prop flange.

george

Here are some pictures of the machine shop at SZP.

Michl TooL Works 805 525 6638
                 805 525 6639 FAX

Owned by Stephen Michl

I dropped off your dwg today with him.
He has located a suitable billet of 4340  at Joregensen for $234.
It is about 100 pounds.

Paul Lamar