George Lendich wrote:

Here is another way George.
You can do away with all the ribs.
Your foundry will love it.
Your machinist will love it.
Your welder will love it.
And Tracy will love it.
The 1/2 inch square .035 4130 steel struts are bolted to
the bell housing with two 10-32 screws each.

Paul Lamar

To tell the truth Paul, I was wondering how to do this for some

aerobatic

applications - that's sure solved one problem - that's the ultimate in
strength and rigidity for the PSRU and should be light as well..
However I'm not sure how that affects the MM  area, the ribs did provide
some stiffness/ strength to these areas.

Now as the face can and will be imperfect because their can be some
distortion in the foundry process but four pads at the perimeter will

solve

that - they can be milled flat with the PSRU face pad - another problem
solved.
This could also be varied to accommodate different length prop shafts

for

different applications.

Is it starting to look too Agricultural !?
George (down under)

That's OK :)

Paul Lamar

I know the steel ring (at the front of the PSRU) is the strongest approach
but can lead to machining tolerance problems (i.e. too big or too small). I
know Tracy's PSRU is fairly thick in this area - do you have any other
suggestions to affix the strengthening rods to the front.

Also would round be better (strength wise) than  square.
Are you sure Tracy will love this, he could have easily done this to the
plate.
George (down under)

Round is much harder to cut properly to fit. There is little difference in weight
in this application. Square is a lot more expensive but we are not
talking about a lot of money for material here.

Just slice the steel ring and use a few short machine screws into Tracy's casting.
Here is a real old picture showing the extra meat in Tracy'PSRU casting.
Taken in April of 2000. Also my rough sketch of Tracy's PSRU made in Oct. 2000.
You could also make a steel cup that also held in the prop ball bearing instead
of the aluminum washer shaped plate Tracy' now uses. Problem is
it then might not work with Butch's electric prop.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.