Here is a quick and dirty cut and pasted 3D. This is looking heavier
and heavier sand cast in aluminum. I am beginning to think Don Dunbar
is on the right track.
When you figure the weight and the machining cost of this thing you
are up to a RX8 bell house cost. Here is a picture of the RX8 starter
and manual TX light weight die cast bell housing. The RX8 auto TX bell
housing is not suitable.
If I were you George I would make yours to fit the RX8 bell housing.
Sorry I did not think of all this while Butch was still here but I
just
got around to making a 3D on his new design.
Paul Lamar
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Paul;
How that ever became my suggestion escapes me, (I must have had a LOT more than my usual glass of wine that night)....It's not my style (Ugly)....Too heavy, and most important, it forces & handicaps the 3 & 9 o'clock users (The MAJORITY) into lugging around all this extra dead weight for nothing.....Not to mention that it actually weakens that whole bottom of the Bellhousing...However, George did suggest this not to long ago but I shot him down quickly on roll-out, I even thought I hurt his feelings, but as it turned out he still loves me :)
On the subject of Auto Bellhousings.....I agree and recognized it from the very beginning that Don Dumbar was/is most definitely on the RIGHT track, and licked the "Auto bellhousing are too Long for our use Syndrome", which has beat a lot of us to the ground simply because WE were all trying to do this by adapting whatever popular PSRU was available (Tracy's).....Instead, Don did the unthinkable to many of us, "Design a PSRU from SCRATCH, to take advantage of some of that nicely protected space available inside the Bell housing and make it work, and lighter to boot.....I give Don 10 points for this stroke of Geniusness...However the weight is still a big factor for us to consider.....And weighs heavy on our endeavor..Couldn't resist this intended Pun :-)
But aside from this, we're still in the same old pickle Jar Guys....IMO, Georgie and Group is the only one preparing to run with this ball, plus extras to boot..And he'll have a Bellhousing waiting for it...He's going to be hard to beat in weight and quality.
But what does all this have to do with the builders out there (The MAJORITY) who own or will soon own a Tracy ReDrive??....Do we simply tell them buy another or a different one or you're stuck with using a plate if they don't want to?? ......I certainly won't, that's the purpose for the Universal Bellhousing to fill present and future needs at an affordable price tag.... Which brings me to the subject of price, I would be totally shocked if this Bellhousing cannot be manufactured for well under $600.00
Butch
I am worried about the weight and cost. With 5 mm cast walls it will
be heavy.
I'll know more when I do a 3D.
There is another alternative and this is to disassemble Tracy's drive
and
install the major parts in a new cast case that fits the stock RX8 die
cast bell
housing. Here is a picture of Tracy's shaft, ring gear, planet carrier
and front bearing assemble. The stock die cast bell housing where the
600 ft pound prop gyro torque is applied is much stiffer due to its
cone
like shape.
IMHO with all due respect to Tracy the warrantee issue is not that
big a deal. Anybody that can build an airplane should be able to
overhaul
the gear box. Unlike the Ross, Tracy's box is easy to disassemble.
Here are pictures of Don's housings for comparison purposes.
I don't want to discourage you guys but we need to explore all the
possibility
as casting a bell housing and machining it is a lot more expensive
than
casting a gear case and machining it. Most of the later work can be
done on
a lathe and not on an NC mill. There is also a possibly of using some
of
Tracy castings and housings with the stock bell housing.
Paul Lamar
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