Clutch disc material identification

The bronze wheel is sandwiched between the red discs.
When the knob on the right is tightened everything is squeezed together locking the wheel to the shaft.
The discs are very hard. Don't if that's the way they're supposed to be or have hardened with age.
I soaked them in oil for a couple of weeks but that did nothing.
I'd like to make new ones.
Anybody have an idea of what would be a good material to use ?
Thanks, Greg.

It looks like they could be vulcanized fiber.

Rob

Greg,

I can't tell what they are made of but it doesn't look like any typical friction material I've ever seen. I have used hubs called 'torque tamers' which had the same components as your unit. I would go to McMaster-Carr and order some friction material of the appropriate thickness. They have sheets of different material..take your pick.

Stuart

Vulcanized rubber? Not seeing fiber - but it could be there.

Look up "Top Rubber" which is one current trade name for Vulcanite.

Early vulcanite was frequently red and used as a base for turn of the century dentures.

You could try "Belzona" which is a black rubber epoxy: mixed like epoxy (two part) the substance hardens to "hockey puck" like durometer - hard but a bit elastic.

Joe in NH

Agree Stuart's "torque tamers" ref, and Joe's red vulcanized.

"Real" friction material can be had in red. Reason my XJ's front alloys have pink dust where they used to be black. But.. those would trash the more expensive Bronze component in a New York Minute.

Looks like a mere kiss & hug is wanted, not hardball drag.

Fabric-in material might last longer, but it doesn't look as if these need to be any more durable than the originals were. Just make more than one set once you get set up. Superstition mayhap, but so long as spares "exist", s**t seems to not wear out and NEED them.

Joe in NH said:

Vulcanized rubber? Not seeing fiber - but it could be there.

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It has nothing to do with rubber.
Also called vulcanized fibre(different spelling of fiber).

Vulcanized fibre - Wikipedia

Still being made. Made in red, sometimes called brick red, black and grey.
This is what was used by machine tool makers.
Usually made from cotton cellulose fiber.

Vulcanex(R) Vulcanized Fiber: Oliner Fibre

Rob

Thanks everybody for the suggestions.
It's from a Studer grinder so who knows what the Swiss were using ?
Obviously the wheel needs to be centered over the worm.
So how critical is the thickness of the left hand disc that goes between the wheel and that solid shoulder ?
And would any compression of the material affect the worm and wheel relationship to an unwanted amount ?

I have antique Hardinge lathes and can describe two applications for fiber washers in those machines. They used a fiber washer between the left end of the headstock spindle and the manual collet closer. Later models, starting around 1940, have a ball thrust bearing built into the collet closer knob assembly.

The headstocks with plain bearings (1903 to 1938) have a ball thrust bearing to the left of the cone pulley to take the thrust of drilling and turning toward the headstock. On the right side of the cone pulley is a fiber washer with minimal side clearance to prevent wear of the adjacent surfaces of the pulley and the headstock casting. The washer gets some oil that leaks from the right headstock bearing. Most lathe operations do not cause thrust toward the tailstock, so the fiber washer is mostly there to limit endshake when not using the tailstock center while turning or threading.

Larry

rustytool said:

Thanks everybody for the suggestions.
It's from a Studer grinder so who knows what the Swiss were using ?
Obviously the wheel needs to be centered over the worm.
So how critical is the thickness of the left hand disc that goes between the wheel and that solid shoulder ?
And would any compression of the material affect the worm and wheel relationship to an unwanted amount ?

Click to expand...

Rob may have nailed it.

If you want to compare a sample, I THINK it is the same material as at least one red, not-elastomeric, ring-washer is made of in a bog-standard blister pak of assorted plumbing washers on the wall at most Big Box.

Now even if that IS the original material, finding a source in the size and thickness needed in small quantity may be challenging.

I'd be tempted to try fabbing new ones that functioned near-enough the same as OEM from "grade" Linen Bakelite. Or perhaps even a red polyolefin or polypropylene kitchen cutting board. Even "fossilized" bamboo engineered flooring could work, though it has a naturally high Silicates content and is more abrasive than wood (Bamboo is actually a grass..), it is also more stable, humidity and temp-wise than woods, even more so once impregnated with the resin - or wotever - for the "fosillizng" process.

Or.. mayhap that so-called "fossilized" process does NOT use an impregnant, and is but another variant on the Zinc Chloride binding of cellulose in the Bamboo rather than "vulcanization" of processed paper? Above my curent pay grade. Or at least beyond any chem lab gear I still have functional.

All of those "solutions" sound kinda "redneck", yes.

But I don't see the temperatures, pressures, nor wear factor being all that challenging in this particular application.

And.. so long as the Bronze is not damaged, you can always try for a better material as it is a simple part, shape-wise, and should take less time to fab than is needed to install.

2CW

When the exterior surface is scratched it appears to be fibrous.

rustytool said:

When the exterior surface is scratched it appears to be fibrous.
View attachment 224982

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Now THAT looks like a processed LEATHER or leather by-product.

That could fit, too. There are/were "vucanization" methods for it. Maybe what you need is old-style shoe-sole stock!

Luggage handles. Around WWII or prior also come to mind.

Any idea when your machine was built?

It's such a rare machine Studer doesn't know when it was made.
I'm guessing towards the end of the Type OB production.
This is a Type 1.
Maybe the 1960s ?
Would leather swell with oil to cause misalignment of the worm and wheel ?

Greg,

From you posts above it appears these red discs run in lubricant inside the gear box. This certainly rules out any 'off the shelf' friction material..IMHO

The alignment of the worm and wheel is really critical to wear. The picture of the low speed worm looks like it's in pristine condition.

Stuart

Yes, It all runs in an oil bath.
The original worm was trashed but Dan in Oakland just made me a beautiful new one.

rustytool said:

It's such a rare machine Studer doesn't know when it was made.
I'm guessing towards the end of the Type OB production.
This is a Type 1.
Maybe the 1960s ?
Would leather swell with oil to cause misalignment of the worm and wheel ?View attachment 224984

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Oil? Not usually, no. Leather is a protein. Living critters make all sorts of miracle material out of that stuff. And then we added synthetics and hybrids that used recycled or scrap leather.

Check out cone-head drive belting and legacy workboot "uppers". "Oil tanned" was once a favored option for boots for linemen and the forestry industry.

More importantly, leather has been used for pulleys and brakes as well as clutches, and best of all - oil SEALS -and for Donkey's Years.

WATER can mess it up - turn it back into FOOD for something or other.

Oil usually preserves it.

This part of the machine had some water get into it during its long hibernation which probably accounts for the condition of the discs and worm.
I'm going to see if I can source some leather.
There is a cobbler in town.

rustytool said:

This part of the machine had some water get into it during its long hibernation which probably accounts for the condition of the discs and worm.
I'm going to see if I can source some leather.
There is a cobbler in town.

Click to expand...

Perhaps a stretch of imagination, but.. I can see possible circumstances wherein some previous minder COATED those discs in an effort to restore/prolong their service life.

Meaning the red material may not even have been "factory". Or.. maybe it WAS, and even so was a coating/impregnating treatment.

End of the day, you still may have to take more than one go at finding a material that "Just Works".

At this stage, my first choice might involve taking two of my hole-saw collection and doing the dirty to a bit of common cord-reinforced conveyor belting material.

At least it isn't a pair of balanced Herringbone gears in some odd pitch..

You might try wintergreen oil. No not kidding it will soften hard rubber and make it pliable overnight. Vintage motorcycle rebuilders use it alot on air box fittings it will not stay soft forever over time it will re harden but if its runs in oil it may stay longer

44dwarf said:

You might try wintergreen oil. No not kidding it will soften hard rubber and make it pliable overnight. Vintage motorcycle rebuilders use it alot on air box fittings it will not stay soft forever over time it will re harden but if its runs in oil it may stay longer

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Methyl Salicylate, mostly. That's the distinctive aroma found in "Marvel Mystery Oil" which is otherwise mostly kerosene and a touch of red dye.

A mere bandaid in this case, and too late by half, even so.

There isn't enough left undamaged of the originals to even make a good take-off as to original thickness, etc.