Hi Paul

The main gear and pinon weigh 21 lbs and the spool 11 lbs , i can buy
the aluminum front housing from www.nationaldrivetrain.com

pinion support al at $155.00

i have to choice of aluminum housing with 3-06 bore bearing at $475.00 or the 3.25 bore at $475.00

The full spool with35spl at $145.00 or the 40spl at $265.00

Gear and pinion at 3to1 ratio $165.00

They sell bearings but i need good advises about the one can stand 6000 to 7000 rpm
I want you Paul to make a look on those parts and the only part i need to
fabricate is the aluminum rear housing.

I know a few good machinist and i been graduate as technician machinist
beginning 60's but it been a long time , may be is a good time to buy a
maling machine and late for my project or get an experience one and let do the work

Do you have any suggestion about housing design???and prop shaft
arrangement with trust bearings

Jean Prudhomme

Those spool bearings are bullet proof so you can probably use them for
prop thrust bearings. 7000 RPM is no problem for take off.

Find a smaller ring and pinion in the 3:1 range.
What you have so far is too heavy.
Take a look at this outfit. http://www.arrowgear.com/

I would build a tig welded steel housing out of .049" with ribs. It will weigh
the same as a .150 aluminum housing but it won't expand so much
with heat and change the gear mesh.

A two inch or three inch diameter carbon fiber prop shaft is the way to
go. You want it stiff. Use a needle bearing on the outer end to cut
weight. Ross used prop shaft needle bearing for years with no problems.

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We sent out an exe on the original and a lot of people did
not get it. Here is the pdf version.

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A stock Mazda RX8 carbon fiber prop shaft would be ideal.
Here is a picture.

Paul Lamar

Ford have 7 1/2 dia 10 bolts at 3.08 ratio and weight 14 lbs but i
can,t find the appropriate spool shaft 79-83 Fairmont,Granada,Pinto & others

Jean Prudhomme

That sounds good as you will need to make a spool anyway.
It must be bonded to the carbon fiber prop shaft.
A traditional steel shaft would be too heavy or not stiff
enough. You want a very stiff shaft. The stiffness to
weight ratio of carbon fiber is several times higher
than that of steel.

The epoxy shear bond is about 3,500 pounds per square inch.

That means a 3 inch diameter shaft has about 9.5 square inches
per inch of shaft length. That means it will take 32,980 pounds
to pull them apart with a one inch overlap. If you twist the
shaft it will take 49,470 inch pounds or 4,000 foot pounds
to fail it. To be really safe double the shaft over lap
with the spool to 2 inches bond lenght.

Here is a source for carbon fiber tubing.
http://www.carbonfibertubeshop.com/filament%20wound%20tubing.html


Paul Lamar

tHANK,S pAUL

i KNOW YOU ARE VERY GOOD ON DESIGN COULD YOU SEND A SKETCH ABOUT YOUR SUGGESTION ON SPOOL DESIGN WITH PROP SHAFT.

Jean Prudhomme

Yes. I'll do that soon.

Paul Lamar