-Excellent idea on the stiffening ring Paul. I would put a draft

taper

on the

outer diameter. Will also cut the weight of the ring by 35-40%

-On the wall thickness for the PSRU's mounting thru hardware I would

make

that .200 inches thk. (5mm)

-The 5 upper and 3 lower support Ribs must go around the edge

transition

radius for a height of at least .500 inches (13.7mm) and meet up

with

the

perimeter Flange Ribs. This will stiffen that drum skin very nicely

and

makes

it homogenous in strenth at a very small weight penalty. A BIG

bonus,

especially for the 20B crowd (Are you listening Cosmans) ;-)

My comment for now is, I LIKE IT, I LOVE IT..Very Schmooth (Shiek &

Smooth)

DO NOT BEGIN fabrication until we finish looking at it and we hear

the

subscriber's comments....Are you listening George??? Put down that

tool

this

instant!!! :-)

                                              Butch

Butch,
Reading you loud and clear - I'm just relieved to get to this stage.

As I thought my ribs are a little overkill at 27 mm at the apex, I will

do a

profile drawing of the ribs  and get your comments Butch!

BTW I don't like the stiffening ( 40 mm face) ring approach as it adds a
great deal more complexity and machining. This would also have to be

tapered

and adds to much weight IMHO.

Hey anyone want a prototype which is very strong going at well below

cost

price - after I've finished with it !! ?
George (down under)

No machining required on the face ring George. The ID of the face ring as

cast clears

Tracy's PSRU. Yes it does make the pattern trickier but the weight savings
are significant as it does away with most of the 180 mm diameter 15 mm

thick center plate.

I suggest you find somebody with a lathe and taper it inside and outside

for draft.

Then bond or screw it to the rest of the pattern. It is only 1.6 inches

high.

If you going to complain about it I will turn one out of aluminum myself

and ship

it to you :)

Paul Lamar

Paul and Butch,

I know you both like the stiffening ring concept - but I don't.
I believe you like it because it adds strength and rigidity, I don't like it
because it adds complexity, both in  terms of pattern fabrication and
machining.

How about a compromise to suit both parties !?

Firstly, my own design would benefit from a integral extension to the
housing to accommodate the Planetary. ( not unlike the Ross). This is not my
original plan, but I can adapt and the benefit is one casting type.

This is a logical extension to your stiffening ring as the ring become the
planetary housing which is separate in Tracy's design. In Tracy's design the
tube is a separate component whereas with the new design, the drive shaft
casting now bolts directly to the bellhouse extension  (shorter bolts into
an internal flange or some other bolting arrangements).

I don't understand what limitations I have in this regard because I don't
know the configuration and dimensions to Tracy's unit (other than the bolt
pattern).

If you think this has merit - we can further discuss the other issues.

This design should  also provide more weight reduction overall.

I discussed the need for the necessary jigs to hold down the pattern with
the local machinist (my Pommy Mate up the road). He tells me POM stands for
Prisoners Of the Motherland.
Believe me Paul, there is a lot needed to hold this sucker down for
machining, however my suggestion will give a larger footprint - which will
help.
This way I can hold down the machining costs, but I still have a one-off
costs in the Jigs.
OK!
George (down under)

I need some sketches or drawings George. 


Putting 12 one inch high ribs inside between Tracy's mounting bolts would work well. 
One rib between each bolt hole.  Run them all the way to the center slug that holds 
the shaft seal. The machine shop should like it as now the front surface is completely
flat.

Paul Lamar
 
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