A few minor problems for the 13B. One hole was ten thou
 off or so but it could be drilled out with no problems.
 One cup tab was a bit too long so that could be hacksawed off.
 We had a few typical bolt circle problems but easily fixed by
 drilling the holes out to 27/64th instead of 10 MM.

 Other than that the 13B was usable. The starter hole
 was a bit on the small side but I can set it up in my
 cheap Chinese mill and bore it out about .020.
 The starter hole should be 2.640.

 I was working from Tracy's dwg and I should have
 checked the dwg against Tracy motor plate which I also have.
 The drawings had a few errors and I probably made one or
 two my self. The dwg does not match Tracy's plate :)

 The RX8 extra bell house bolt was way off by about a half inch so
 that is going to require a whole new dwg which I have about done.
 I want to make the plates fit both the 13B and the RX8 motor.

 Jeff I'll get the  fixed dwg to you in a day or so.


 Paul Lamar

 Paul

   So this is usable. If  you want I can open up the starter hole
 here. It
   measures 2.620 on the solid model. I depend on the solid model for
   geometry for expediency. If you need to digitize the bolt
 pattern on the
   housing we can do that. We need absolute numbers. I do not
know the
   difference between the RX7 and 8.  the half inch hole problem,
 does that
   make it unusable??? No worries, we just get it right for the
 folks that
   need them...

   jeff

   I'll ship it back if you want it. I only have one RX8 end housing
   and it is on my RX8 P-port test engine which I don't want to
 take apart.
   I think I got it measured fairly accurately.

   If you have a 13B end housing that would be a good one to
digitize.
   The solid model is now fine. I fixed it. Jarrett has it now and
   he is converting it to a Solid Works file for you. I made a
 couple of
   other changes while I was at it. After you do it three or four
 times   you get better and faster. The new version is much more
 accurate as
   I had been there and done that :) All ribs are now the same
 width and
   parallel. We need to drill all the 10 mm holes out to 27/64th
 as that
   will ease the bolt circle problem.

   No change in the back pattern.

   We should look into a spun or pressed bell housing and use the two
  hollow
   dowel pins on the end housing to locate the unit more
 accurately. Along
   with a lighter weight gear box of course :) The bolt and spacer
 idea is
   less than ideal.

   Paul Lamar

  Paul

  I think when you send me the new geometry I will make a
 template, send
  it to yo then you can check for fit. I am not in favor of
making the
  holes larger. I can use my machine as a CMM and get the number
 exact.  I
  did that with the rotor housing and it is perfect.... We save these
  master coordinates for all future parts. This should be done all
 around  the block.
  I have machined bell housings before. Lots of aluminum chips but
 can be
  done fairly quick as opposed to finding and getting someone quote,
  setup, bid,etc. Lots of time and money..
  My guess a billet block of 6061 for a bell housing would be at
 least 60
  lbs..Al plate is a little over $3.00/lb.  Figure $200 for
 material.  It
  will machine down to about close to 8  lbs or less. If the
 housing is
  not too complicated with lots of ribs, this could be machine in
 1 day.
  More,  obviously for the first article sample, but for any
 production  at  all,  $600 to $700 is doable. Eventually get a
 cast part , but this
  way we could get something out cheaper and sooner...
  I agree the bolt and spacer arrangement needs to be fixed....

  jeff

  No doubt about it that is the ultimate solution. I rejected it in
  the past because of the cost. Prices have come way down on NC mill
  stuff as a lot of people have the machines payed off.

  The problem with sand casting is weight. The foundry has
 problems with
  anything thinner than .2 inches. Also the cost of sand castings has
  gone way up. NC milling is now more competitive.

  Try these until Jarrett gets the SW version out.

  Paul Lamar

 Paul

 Tell Jarrett no need for file conversions anymore. I have a new
SW2009  seat so all will work directly......

 jeff

 Great. Thanks Jeff.
 I'll bet it will load Rhino native directly :)

 Paul Lamar


Paul, I did this over lunch so it's the quick version. I didn't
put the cups
on as we know they are strong enough. I just fixed one end where the
cup goes [the farthest from CL] and the second one I fixed it such
thatit was still moveable from the first yet fixed in the vertical
plane [similar
to how flexible an engine mount 'could' be. The trick here is if I
make both
ends fixed [ie cast in concrete] then there is some degree to
stress that
is carried via tension between the two fixing points. When I put
one fixed
and one fixed in the vertical only ?I think we get a better
representationof the loads w/ a mount that has midle deflection at
load. It looks ok still
to me.. but I haven't spent too much time going over the results.
I can do
the 'real deal'  test later tonight but thought this might help in
the mean time.

Let me know..

Jarrett

That ia much better.

Jeff this is the new design fixed with the RX8
hole in the right place. I also added a rib on the highly loaded
left side. The stress level is now very conservative which is what
I was shooting for.

Thanks Jarett.

Paul Lamar


No problem, do you want me to do one w/ the cups on it.. or are we good at this point?

Jarrett  [geeze I've got to slow down when I'm typing.. and then proof read.. sorry about that...]

NO cups needed. We are good. Jeff might need a solid works file.

Paul Lamar