Paul There is the Mercedes coupler i talked to you before ,they have
   several models on EBAY and very cheap,you can design the shaft
without
   spline but only an adapted flange cup to meet the coupler and the
flexwheel
   as safety in case the rubber fail.I do have an idea of the shaft
design with
   this Mercedes coupler.Ths one is for the 550 model
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   http://tinyurl.com/3fhm24k


   Jean Prudhomme

   Does anyone have dimensions for this type of coupler?  I interested
in the
   OD and the thickness in particular.

   Randy

  used to use own a few bmw 2002's back in the day.  These were used
as a flexible coupling between
 the driveshaft and the output flange on the transmission (called Guibo
joints).  Having broken a few
 and then needed to call a tow truck, I'd never use one on my airplane.

 half of the bolts were on the output flange, half on the driveshaft.
When the coupling came apart
 it was usually spectacular.

 Am I missing something-- are you gents suggesting using the flex disc
in another manner?
 William Mason   Yes i know on the car you do have lot of bending
action and twisting but
it have one model which
 have a steel cage and all bolting are lineup to the same
circonference so
if it fail it keep turning
 the shaft ,we can use a strongger one similar to the Mercedes 500 and
built a similar cage and will
 be stronger and will keep the sungear shaft driven in case it fail.The
steel cage bolted to the
 flexwheelIt worth to make one and test it.There is the picture of the
one
i am talking and the 500
 Mercedes which i am sure is more stronger then the one you had on your
car.

 Jean Prudhomme



Hi, remember most oem couplers are used behind the gearbox and see about
3X engine torque in first gear.  If you use a coupler that is sized
too big
it will be too stiff and might not help at all.  Unlike most of the
rubber
doughnut, the SGFs are reinforced with tire cord.  Most are just rubber
with bonded in bushings.  I designed a Holset type coupling for a rpv
diesel project and told my friend to use the softest rubber rods he could
get from McM. He put hard urethane rods in.  It did not work at all.

Murry I Rozansky




Be careful when installing, they need a spigot and socket to keep the
drive and driven shafts aligned, most of the european types I have seen
have the above and has a type of ball so the drive shaft can move in
relation to driven shaft.
     John Burey.