The aluminum billet version was getting expensive. The material
alone was $66. I know I just bought some today. I had to pay $16
just to have it cut to lenght.

Then I was having trouble finding suitable 10 mm 1 mm pitch metric
screws. I never found any I was completely satisfied with. Making
our own was getting expensive.

The welded version can use the stock 10 mm 1 mm pitch bolts as it
is only .125 thick which can replace the stock clamping plate

The light really went on when I thought of welding the walls
directly to the steel spline plate.

No bolts or screws needed to bolt the spline plate to the
coupling. The spline plate is half the coupling.

Nothing could be easier or simpler.

The walls are rectangular .75" by 1.5" 4130 tubing from Aircraft
Spruce. I have some in stock.


There must be only three walls because there are six 10 mm bolts.


Here is what it looks like. It fits the stock 2 rotor flex plate
but does not stress it. All torque is transmitted by the six 10 MM
bolts.


I will weld one up and send it to you for testing Mark.

Paul Lamar

What amazed me is the coincidences. The rectangular tubing just
happened to be the right dimensions. There are only two choice's
from aircraft spruce. 3/4 by 1 1/2 is one of them. This leaves
plenty of room for a couple of needle thrust bearings between the
spline plate and the gear box adapter plate.

BTW asymmetric rubber bushing might work out to be the best
configuration. Most of the rubber on the compression side. The
acid test will be the lowest engine RPM that does not cause
resonance. That does not mean it is not mitigating destructive
torque pulses at higher RPM's. The kind that shear bolts and pins.

Paul Lamar

Carrie Beasely was right. Powdered metal. I won't weld to powdered
metal. Back to 2 pieces 4130 sheet metal. Hard as heck. I ruined a
band saw blade on it. It came with all this stuff inside for $37.
Hack saw in the lathe does not work well.

Schabs Parts 12715 old plank road New Lenox Il 60451

Paul Lamar

This fixes the clitch. New 4130 welded sheet front coupling. The
4130 2.75" OD tube .120" wall clears the big nut and keeps the
rubber from getting chewed up by it.

This is what I will build. No welding to the powdered metal spline
plate. Separate 4130 front coupling weldment.

Paul Lamar



Paul,

That looks good to me. How do you plan on making the silicone
dampers?

If you can get the pieces cut to size and send it all to me, I can
weld it up and then test it.

Mark

No welding on the spline plates. Too risky.  New 4130 front part instead.

I was thinking we could buy fabric reinforced silicone rubber sheet
from McMaster or AC spruce and cut it to shapes. Then glue them together
with red RTV to form crude 3D shapes..

OK I'll do that Mark. I think I have located mild steel tubing of the right
sizes. The tube parts are lightly stressed so you can weld it to
the 4130 parts.

Paul Lamar