Paul

are you sure you want to use 7075??
I have a great source for 7050 with certs cheap cheap cheap it's all
boeing scrap.
maore than you will ever use. My machine is not being used at the moment.
I can machine the plates and squares
if you send me the drawings.

Tony

I'll get back to you when I get back from check rides Tony.
What dwg format can you use. We might try a built in planet
carrier on the 4 inch aluminum shaft.

Perhaps Ed needs something right at the moment?

Paul Lamar


This picture will give you a feel for the strength and robustness
of this type of four inch diameter aluminum prop shaft  PSRU.


Paul Lamar


That looks like it otta handle it. The shafts on the 2.85 are 4.17", which
leaves me with perhaps a .020 wall thickness; if I edm for 3/8 bolts. I
could likely find 9mm bolts and end up with about .030". I don't know what
the limit is for the lazer, or the minimum needed to provide a good
surface
for the pinion bearings to ride on.

Ed Carver


I have opened an order with Sunshine metals. Order pending receipt of in
house credit app. and fund transfer. The base price for 28 inches of 4.25"
7075 t73 round bar is $205, of which you want 14". Tax and shipping will be
added to the end total.
This company will not let me pick it up directly:(

Ed Carver


OK Ed I am in for half.

------------------------------****----------------------------**--

Ed, this is what the housing casting will look like more or less.

Most of the thick stuff at the back will be machined away to
leave a 3/8th thick flange to fit this bell housing.
Some of the gearbox will extend into the bell housing.

The idea here to keep the overall length, from block to
prop flange the same 14.5 inches as Tracy's and Ross's gear boxes.

It is  a trade off to make the pattern simple and cut
the overall cost of the casting. No core box is required.
However more molten aluminum is used.

As shown the casting is ten pounds but 3.4 pounds of that
will be machined away. Total housing weight will then be
about 7 pounds more or less.


Paul Lamar


Ok excellent, just about what I imagined.  It makes it easy to bolt on this
way and looks good too.

Ed Carver

Ed, I am making two prop shafts out of 6061 T6.

I think it is plenty strong enough. Got 15 pounds of material (12" long)
today
at Industrial Metals for $3 a pound and my friend is drilling a two
inch hole as we speak. Do you want one? I'll give you the final weight when
I get it machined.


Paul Lamar

Ed,

If you can make me a 10" BY 10" block of wood 18" long I'll
have my guy with the big lathe make us a housing pattern for the
the housing casting. You can laminate it out of knot-less 2 by 10. :)

BTW I noticed a foundry on San Fernando road just south of the  118.
East side of the street.
You might stop in and see what they charge per pound of cast 356 alloy.
I did not have time to day. You can print these jpg and show
them what it will look like.


Paul Lamar


Yes, there are many foundries around here. I hav'nt begun to look for the
really good ones. There are mixing foundries, I will find them eventually.

I will get you a wood block this week. I'm doing wood right now anyway
while remodeling this house.

I will also deliver the 7075 when I do. So let your machinist friend know
there are 4 more 7" lengths coming. Presently, this material is a 28" bar.

Wish I had known you were coming here. Industrial Metal is only a few blocks
from my house. I could have handed off to you the 7075, and the block of
wood.

Almost back to where I was before I was interrupted by the broken water
line under the slab. When would you like me to bring the wood block?  I'll
make the trip a beach day for the kids at Oxnard.

Ed Carver

We used to use American International foundry but it was sold and the new
owners doubled their prices to pay off the loan. Typical :)

860 Arroyo St
San Fernando, CA 91340


Great Ed. I'll use the 6061 T6 as a non functioning prototype.

Anytime on the wood block and the beach.

Paul Lamar