Hi Martin you don't give a lot of information on what sort of pulley . Belt, V, multi V, diamiter and speed. Jones and Shipman in eternal grinders have a flat belt tufnol pulley running at very high speed.

David

Prepare fro dust when machining. When I did a big quantity for someone years ago even with a woodworking style vacuum sucking a tornado and bowing the dust outside enough escaped to put a red film on everything in the workshop that took years to finally remove.

Tufnol gears are often used in a changewheel train to reduce ringing and I think the Meddings drills have one in the backgear. However there are different versions and some 'grain' so select with care.

You should look for the cloth type Tufnol and not the resin paper type. In fact if in heavy duty or high speed use a bush in the center, perhaps flanged and pinned.

I had one as a timing gear in an Opel Kapitan and it sheared teeth way up in the NFD in Kenya, the replacement was an Alu. one.

Clive

Add to above. Textolite is apparently a fabric based material but various fabric is used and the resin varies as well.

.

Martin,

I'm struggling to find any supporting evidence for that closing assumption:

" … if at very little or no additional expense a reasonable material could be made."

I suppose it depends on your definition of 'a reasonable material' but the manufacture of the better Aluminium alloys is certainly not a trivial matter.

MichaelG.

.

http://www.raaltd.com/aluminium-plate.html#casttoolingplate

Edited By Michael Gilligan on 25/03/2018 10:38:55

Tufnol are very helpful if you ask their technical department. I many years ago worked close to the Tufnol works and could call in to ask recommended grades for my application, sometimes coming away with a "Sample" I suppose those days are gone now though. I don't subscribe to your theory on grades of aluminium they all have a purpose especially if welding is involved.

.

Returning to the opening post ….

If you need low inertia; there is, of course, an alternative approach:

Converting the drive to Poly-Vee would allow the use of much smaller pulley diameters.

and, if you need to further reduce inertia; it would be worth considering a conversion to variable frequency drive.

MichaelG.

Martin: You must be looking in the wrong place?

Grade 1050 is almost pure aluminium. It is 'orrid stuff to machine, think warm fudge. However, as far as I'm aware (at least from my professional aluminium stockist) it is only available in sheet form. Not surprisingly it is intended for sheet metalwork where it bends without cracking. Any of the common aluminium alloys such as 2014, 6082 or 7075 are available in plate and bar, and machine well. By far the most common alloy (6082) has a good combination of strength and machinability and is widely available from a variety of sources ranging from professional stockists to Ebay.

If you really need a low inertia pulley make cutouts, like a flywheel.

Andrew

Cloth type Tufnol will likely be fine. I used to have a load of keyed Tufnol gears I acquired in an industrial scrapyard and they were clearly capable of demanding application given how they had been used.

Not easy for anyone to make a meaningful recommendation though from the sketchy information given. I used a Tufnol for a variety of vee pulley applications without issue but I didn't do any proper design calculations and they probably weren't close to their limits.

If you have a suitable sized piece, I'd just get on and machine it up. If you were up to doing the appropriate design calculations you'd probably have the answer by now.

Murray