If you think there is 10 lbs to save in Tracy's PSRU, that's huge
 considering CG and all...If someone is willing to get the necessary
 components that can be whittled and you direct in the ares to be
 machined, I
 would be willing to do this for a very small sum to cover the tooling and
 possibly the fixture material, about $200.  NO other machine shop would
 touch something like this for under $1000 .................

 thanks

 jeff

 I'm interested! My psru still in the crate.
 C. Smith


 Here is another way Jeff. We rejected this idea a few years ago
 because of
 excessive cost. The cost on NC milling has come way down recently.

 The big weight savings is it combines the schertz beam with the adapter
 plate. A schertz beam alone weighs up to 9 pounds depending on the
 length.
 Bob White tested it for us in a crash.

 The right side can be much shorter to accommodate a rad on the cool
 side of
 the engine. I'll do a suggested dwg for you. It is a half inch thick.
 Jerry
 Hey tested it for deflection and Jarrett did an FEA.

 Paul


 I will have bottom Radiator, and what looks like 25.98 between barry
 centers
 if I read the drawing Paul made of the mount for me correctly.
 So combo plate, then some shaving on the housing, what, 19 lbs
 saved???? 8-D
 C. Smith

 Not quite that much as some goes and some stays. I would say 15 pounds is
 possible.
 We should standardize on the asymmetric mount as it can be used with a
 bottom rad or a right side side rad.

 It will look something like this. I'll have to redo that zenair dwg if we
 use this plate.


 Paul Lamar


 I think I like this method. The strength is proven in the crash test. Can
 you proceed with a new drawing for the Zenair mount?
 Jeff, can you make these if Paul sends you the cad file? Cost to produce?

 Paul, what was the depth of the cutaway for the gear housing in the image
 Tracy-PSRU-10-2000-dwg, and how thick should the flanges created be?
 Can the
 RD-1C be safely disassembled by an average skilled person?
 Jeff, with numbers from Paul, can you make the modifications to the gear
 housings? Cost to modify?
 I bought the 4130 sheet for the S-beam, but much of the cost is in the
 fabrication, so I can eat $46 in material.
 C. Smith

 The max thickness on the housing should be 1/4 inch everywhere.
 Tracy got carried away and made everything a 1/2 inch thick or thicker
 in some
 places.

 The Ross gear box was 5 or 10 pounds lighter.

 Tracy's older 2:17 PSRU comes apart rather easily. You take out the
 10-32 screws
 holding the front cover cover on and the large ball bearing should
 come right out.
 On mine Tracy glued it in with red RTV. Then you have to unbolt all
 the long
 1/4 28 screws holding the unit to the adapter plate.
 After that it should fall apart. As I recall on the 2.85:1 the ring
 gear is
 pressed and keyed into the housing so you don't need to remove that.
 Power
 is taken from the planet carrier. Ignore the green and red parts. Those
 are just my idea for a built in torque meter.

 Paul Lamar


 Jeff,

 This may or may not help you. It is looking at the adapter plate from
 the prop
 point of view with a dual set of dimensions. The radial set came From
 Tracy.

 BTW guys I suggest everybody get a copy of free Q-Cad as it works on both
 Windows and Linux. That way I can send you 3 view 2D dxf dwgs and you
 can dimension
 them yourselves if you are interested or need to make the part by hand.


 Paul Lamar


 Other wise I need to do a lot of extra work as modern 3D cad dwgs
 don't normally
 have dimensions on them. They are drawn to exact scale and they can be
 loaded
 into a NC Mill without anybody reading the dimensions.

Paul

Nice 3D.

I put this together quick so it is not be totally dialed in..but just
wanted to show the idea.. all alum. The Purple is a  separate stand off
like Tracy's.  Now showing .625 plate.

It clears the flywheel... I think the counter weight will also
clear........You could dog ear the bottom for engine mounts or mount it
on the PSRU plate as now.

jeff

The reason Tracy's spacers are 3 inches long is to accommodate the stock Mazda
starter. No doubt Tracy's spacers can be improved.

One of the subtle advantages of the combined schertz beam and motor
mount plate is the rubber bushing react the 570 foot pound prop torque
directly rather than having this torque pass through Tracy's spacers
and then into the schertz beam. The spacers then would have only to deal
the 200 foot pound engine torque alone.


Paul Lamar