Thread: OT What material could replace a fabric u-joint?

If you lived around here, I have some chunks of that half inch type belting that I couldn't use for a somewhat different purpose (still a flexible joint).

It's rough stuff, I can't see it tearing out easily. It was hard as heck to cut on purpose with sharp tools.

Other option is litho printing press blanket, several layers of very tuff canvas vulcanised into about a 1/8" thick sheet. Simply cut and stack the discs. Works great holding a over weight landrover exaust on, were conveyer belting fails rapidly.

Hm Look up "Fabreeka" in Googol. Chances are the part you're concerned with is molder withe all those bushings but maybe it can be made satisfactorily from the sheet goods.

Lots of stuff on Google: http://www.google.com/search?hl=en&i...h&aq=f&oq=&aqi=

Buffing wheels?

Cheers, Les.

I know the original intent was to replicate the rag joint there. But if this cannot
be done, a close approximation might be had by stacking multiple discs cut out of
stainless shim stock. I would probably go with a stack of a dozen or more pieces,
maybe 15 thou thick each. It would take some experimenting but I bet the
strength and flexibility would be there, and it could be painted flat black to
fool the casual observer.

Now I know what yer gonna say. There ain;t no such THING as a casual
observer when you take the car to a ralley or a show. Everyone is under there
inspecting ever cotter pin and wire tie and exactly what kind of plating *is*
on that bolt, they never had that when this was made....!

Jim

I was at my friends shop today, he had a piece of belting like you need I should have measured the thickness. Just looking at it I would guess it was 3/8" thick. I could try to get a chunk of it if you want. It looked very heavy and tough.

These are called Hardy Discs and in the states Rudy Rosales is the only person I know advertising reproductions:

RUDY'S - RUDY ROSALES, pre-war Rolls-Royce parts, custom made gaitors, leather spring covers for leaf springs, steering & shock absorber joints, Hardy discs, fabric couplings to order. 4086 E. 71, Cleveland, OH 44105 (800) 248-7839, (216) 641-7711 Fax: (216) 641-0060

He made the set for a 1917 Meteor Hearse I was working on a couple of years ago. I thought he would want mine for samples, but, much to my surprise, he opened a book while on the phone and read off the specs to me. Only thing not correct about them is the Meteor used red rubber and his are black, and the replacements were a bit thinner, so there are now four rather than three. They fit perfect. He also recently made for me a set of steel leaf spring covers for a '35 Cadillac. Perfect in every detail and fast turnaround. I highly recommend him.

By the way -- they were nowhere near $2K. If I can remember I'll pull the old invoice the next time I'm at the shop.

RE; stacked stainless steel discs for shaft miss-alignment; This exact set up is used on the Bell 206/OH-58 series of helicopter to drive the tail rotor. Two yokes 90 degrees to each other, separated by a stack of stainless steel disks, very reliable, but I can't remember how much horsepower the T/R absorbs. Couldn't be much, as the yokes were bonded to the shafts themselves. An important point, is that the washers bearing directly against the 'discs' had a very pronounced radius, to prevent stress concentrations. We referred to the couplings as "Thomas Couplings" but I'm not sure that is strictly accurate.

I saw a big lift sling in a scrapyard the other day that looked to be pretty tough. It was about 6" wide and 1/4" thick. Tough stuff, I'm sure.

Originally Posted by Steve in SoCal

The photo looks remarkably like a Mercedes "flex disc"" used in millions of cars

Steve

BMW uses those too! They call it a "guibo".

"...This exact set up is used on the Bell 206/OH-58 series of helicopter..."

Well there it is. They're using *my* idea. They should give me a free helicopter
for that!!



Jim (am I the only one here, who wants to build a working helicopter? Too many
hours mis-spent in my youth, reading popular science)

Originally Posted by jim rozen

"...This exact set up is used on the Bell 206/OH-58 series of helicopter..."

Well there it is. They're using *my* idea. They should give me a free helicopter
for that!!



Jim (am I the only one here, who wants to build a working helicopter? Too many
hours mis-spent in my youth, reading popular science)

I sure wouldn't want to build a non working helicopter!!

Steve

Working, as in, passenger carrying. Not a miniature RC vehicle.

Jim

Jim,

If you are serious check out Rotorway they have sold a number of kits. http://www.rotorway.com/index.php

Steve

Originally Posted by jim rozen

Working, as in, passenger carrying. Not a miniature RC vehicle.
Jim

Having piloted both, I can assure you that the passenger carrying one is much easier to fly, while being much more expensive to repair.

Update.

I found a source for new professionally made discs. Made to the original specs. They are now available here Universal Joint Flex Disc

And they are less than 1/4 the cost of John Deere discs.

Dave

Originally Posted by thruthefence

Make friends with a fireman. Find the shop where they do their equipment maintenance. Get a length of timed out fire hose, it's very tough material, and you can probably get it for free. Cut & punch your discs as noted above.

Some fire hose is ungodly tough. I took several expired hoses with me when I left the Navy. Cut them into lengths and kept in my trucks for tow/recovery ropes. Not trying to exagerate- I could not break one where 3/8 chain had failed, Have even used it pulling logs with my D4. The easiest way to cut one was in a hydraulic shear as a sharp knife or razorblade would take 15 minutes to get through it.