Subject: Making your own steel coupling.
From: paul lamar
Date: 6/23/2017, 11:35 AM
To: A10-Me-Earthlink


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

The Rotary Engine free News Letter. Powered by Linux. If you want off
the list PLEASE let me know and I will remove  you.  ACRE NL web
site. http://www.rotaryeng.net You Tube http://tinyurl.com/beqqxas
Copyright 1998-2017 All world wide rights reserved.