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 Lamar


   Q-cad installed and running, but it's not really free. It terminates at
10
   minute intervals, then after 100 hrs total for good. However $35 isn't
bad
   for the ability to get some stuff done and not have to take up time that
   could be better spent upgrading Kasauga mills, or designing new stuff for
   rotary aviation.
   C. Smith


   Thanks Craig. I think it is well worth the $35 for a 2D cad program.
   Seems rock solid. I'll send some dxf's for it shortly.
   In fact try this one and see if you can dimension it.

   Paul Lamar

   Paul, I bought a cad program on e-bay for $24 called  DesignCAD  3Dmax
v18
   just to try out the rendering part. It does 2D drafting and 3D solid
   modeling, 3D rendering and animation and has a huge symbol library. I
  seems
   easy to use with all the normal drawing commands etc.  They had about
  fifty
   listings on this program recently.It has multiple import/export formats
   including dwg and dfx as well as a lot of newer ones.You own it outright,
   no
   time or save etc limitations.

   george grimes

   Does it work on that 2D dxf I just sent.

   Paul Lamar


  Paul, The listed import file extensions are   DWG,DXF,IGES,WMF,HPGL,and
  XYZ  . There is a setting for 2D/3D operation. I downloaded the rear
  housing
  dxf file and lost it  on the hardrive. I saved t twice because it showed
  174
  KB and saved as 22.4 KB    I will eventually capture a dxf file  on the CD
  drive where I can find it and try it out

  george grimes

  Well Design Cad does not work on Linux so I can not try different files
  in case someone has problems. Q Cad works on both. Like Office,
Thunderbird
  or Firefox it is a cross  platform application with complete file
  compatibility.


  Paul Lamar



  Paul, does your Rhino run on linux. I am using XP because the programs I
find run only on windows. I got the dxf files off the last post and will
have to find something to unzip with. I bought win-zip and it is on here
somewhere. I wasn't suggesting we need a dynafocal mount, it just seems to
be less material lengths on the motor mount tubin and less engine in the way
of triangulation of the structure and might be stronger and lighter.The
radiators might be mounted to the ductwork  of the lower cowl or under the
motor mount. For side mount radiators like the zenith 801 the extra weight
of a separate frame for the radiators might end up heavier.

george grimes

No Rhino does not work on Linux. It is the only reason I still have a
Windows computer. XP HAS unzip AKA Compress. What version of XP do you have?
Zip or Compress is built into Windows Explorer that comes with XP. You do
use Windows Explorer do you not? A lot of people don't even know about
Windows Explorer let alone use it. Windows Explorer was a bad rip off of
Xtree Gold for DOS.

What you do is "send" a file to a compressed folder. That makes
a smaller file in the same folder you invoked it from. The new file than has
a .zip extension. To un zip it you choose the file and then choose
"extract all". That unzips it and expands it of course.

The reason it is a good idea to compress raw dxf files is they tend to be
large
and they are merely a large collection of ASCII words readable by any text
editor.
If you attach a raw dxf file to an email message they automatically appear
at the end of
the  received message as a huge text file making the message pages and pages
long.
It then becomes very difficult to extract the DXF part from the rest of
the email. When it is zipped and attached it always appears as a separate
entity.

The other problem with a Lycoming dynafocal mount is the 570 pounds of prop
torque is transmitted back through the engine to the rubber motor mounts.
Mazda never envisioned this to happen to one of their engines. I know
Mistral
uses it but they have the opportunity to redesign the rotor and end housings
to accept this level of torque. Mazda had enough trouble with the third
gen turbo engine cracking the end housings around the dowel pins designed
to transfer the front rotor torque to the rear end housing of the engine.
The Le Mans engine was beefed up to act as the last half of the race car
chassis.

0.049 thick 4130 tubing 3/4 of an inch in diameter is .0344 pounds per inch.
A 30 inch long piece therefor weighs only about 1 pound. The tubing portion
is the lightest part of the motor mount. The schertz beams probably
weighs more than all the tubing combined in most designs.

The ideal design is the Questair Venture and Beechcraft Bonanza where the
bottom
of the cowl does double duty as the motor mount.

Paul Lamar


Running windows Vista (yes, the pariah of operating systems) I simply right
click on the zipped folder, select [extract all], specify destination folder
if different than the local folder, then click OK. No added zip/unzip
utility required. In Q-Cad, I select file-Open, browse to file location,
select desired file, click OK.
What is the xxxx.STP file represent? They cannot be opened directly in
Q-Cad.
C. Smith

Those are 3D files that need to be opened with 3D programs
Like Rhino and Solid Works. A lot of the CAM programs like Master
Cam and Surface Cam can load stp or step files. Other devices
like 3D printers, rapid prototyping machines or stereo lithography,
machines can open them as well.

I used the $50,000 stereo lithography machine
at the local junior college a few years ago to make the patterns
and core boxes for these custom cast Mazda intake manifolds.
We sold close to a hundred sets until Mazda came out with the RX8
changing the side port patterns yet again requiring all new designs.
That is one reason the p-port is the way to go as it fits all
Mazda rotary engines from 1974 on.

BTW I got you rotor housings.

Paul Lamar