I have an idea for you Scott.
There is a water jet company in 1500 Airway Circle, New Smyrna
Beach FL. 32168 | 386-424-7333 <
tel:386-424-7333
I have some drawings of a steel coupling that can be made out of
water jet cut steel parts.
Then you will need to find a local tig welder to weld it up.
I have some of the parts. The inner plate that bolts to the
counter weight and the outer ring cut from six inch tubing.
$50 plus mailing.
Use part of Tracy's torque isolator to adapt this to Tracy's PSRU
input shaft. Drill out the rivets and bolt it to the steel output
front plate.
Paul Lamar
Very interesting! I can query the water jet shop, and will order
these parts if the shop can make the rest. No problem with the
welder.
How thick is the metal?
Do you intend for an outer ring to be cut into the small curved
shapes, or make these from scratch? I guess they can be flat
instead of curved?
I also assume the 1.78” is the height of each component, so the
total thickness would be about 2”? I will study my redrive to look
for areas of potential interference.
Please ignore the curved questions of my last post, sorry. Some of
the latter images didn’t display the first time. I see the
connecting elements are square.
Thanks!
Scott Gettings
.050 to .150. Some of the stuff is .083. You make it out of what
you can find :-) The six inch tubing is about .150 wall.
The total thickness is about 1.8 inches. Nothing about this is
critical. One inches would work if your not shooting for 500 HP.
Ignore those square pictures. The latest are triangular or wedge
shaped. The square ones bottom out corner to corner. We discovered
that when we built the TTC coupling.
If I get a little more interest in this I wall make a tool that
bends the wedges in a hydraulic press. Saves a bit of welding. I
have built tools like that in the past. That would pay off as the
same design can be used in new gear boxes. We already used one of
these that was similar in a 3 rotor.
I have not heard back from Kevin so if Kevin finds an NC shop that
can make them out of billet at reasonable cost that would be more
accurate.
In any event once this is welded up it would be wise to balance it
between parallel bars. If your gear box is off the engine please
tell me the diameter of the input spline adapter Tracy is using.
The one with all the rivets. That will control the diameter of the
forward plate.
Paul Lamar
Paul,
My welder can assemble these small steel parts, but is not highly
confident of the precise alignment and balance of the end product.
It looks like some other options are evolving, so I’ll keep this
one on hold.
My gearbox is on the engine, but if you need the exact shaft
diameter soon, I will be happy to pull the it and measure the
shaft.
Other measurements that might be helpful: distance from front edge
of flex plate gear to rear of engine block: 1 5/16” distance from
front of Tracy’s adapter plate to engine block (the total “open”
area between the engine and adapter): 3 1/8” distance from front
of Tracy’s adapter plate to rear face of his riveted spline
adapter: 1 1/4” the front of the spline adapter appears very
close to the rear edge of the flex plate ring gear.
It appears that the total thickness of a new coupler (for Tracy’s
RD) would need to be the exact distance from the rear face of the
bolted area of the flex plate to the rear of its ring gear, which
is the plane of the front of the riveted part of the spline
adapter. This would maintain the dimensions for the thrust
bearings. A coupler that is more thick than this would move the
rest of the RD to the rear, requiring alteration of the existing
spacers (the 3 1/8” distance). A thinner coupler could be managed
with thrust bearing washers.
Scott Gettings
I just happened to have one. The OD of the part in question is
6.188. The long part that sticks away from the engine 1.158 long.
The idea is to turn it around and put the long part inside the
coupling. We worked this out years ago :-) 3D's 5 and six show this
config.
That Ford part raw weighs 3 pounds. There is unnecessary meat on
both sides that I can be cut off if you send me yours. That will
give you plenty of room and save a bit of weight. Some of the
spline part can be cut off as well. 1.25 inches of spline would be
plenty.
Jean is down the road from you in Pompano Beach and he might do it
for you. He has a lathe and a mill. He will need one sooner or
later :-)
Here are a few pictures.
Paul Lamar
Scott, I'll check the dimensions on my RV4. It still has Tracy's
coupling so I will need to change that anyway. I was going to use
it to flight test my new gear box design.
Here are a couple of pictures about what my coupling looks like
now.
Here is what it might cost if you had the coupling NC Milled In US
dollars from the Internet.
Setup/Programming - 40
Fixturing - 60
Engineering Services - 40
Machining Time Per Part - 60
Inspection/Deburr - 40
Test Part Machining - 60
BS Time - 40
Let me know what you are leaning towards so I won't have to take
the gear box off my RV4 just yet :-)
Paul Lamar
Paul
i just drove to Fort Lauderdale and see the waterjet cutter 92000
psi and they can cut up to 8" thick so is not a problem.They will
give me a quotation by the end of the day for 1 prototype and
different quantity, they can cut also the rubber block cushion.
JEAN PRUDHOMME
Thanks Jean. That thickness and pressure is amazing.
Paul Lamar
I revised the drawing and design the stencil template for water jet
cutter., See attached file for each of them plus the file as solid
parts in aluminum. The back plate to suit the ford plate as 1.860 Dia
where
spline shaft attaches.
I will get one sample as soon i get the quotation from them.
JEAN PRUDHOMME
Looks good Jean.
BTW you can simply weld the short piece of 6 inch diameter steel tubing
to the flex plate directly for the steel version. Fill in the half moon
holes
with scraps of steel.
In my new gear box design the input shaft is 1.5 inch OD hollow tubing
so that does away with that 2.5 pound Ford powdered metal part
Tracy used. Won't work with Tracy';s box of course. The reason for this
is the connection to the coupling is stronger and so is the
connection to the sun gear. One can use extended point
set screws in both cases.
I found another one of those cut down Ford parts if some one wants one. $50
plus mailing cost.
One other thing. Here are the motor cycle origins of this
coupler idea. Attached pictures.
Paul Lamar
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