With the parts all cleaned up, they were chucked up in the lathe one at a time to drill/bore out the center hole to match the ID of the bevel gears:

Then it was time to start mass producing the shaft bearings for each of the discs. I cut short lengths of bearing bronze, long enough to just get two bearings out, and turned each end down to be a close fit in the holes.

Here they are after parting off and cleaning up the parted ends to final thickness:

The inner corners of the bearings were beveled slightly to give clearance to the inner ends of the teeth on the mating bevel gears. Then each bearing was glued into place, using some thick high strength retaining compound. I'll let them set up overnight, and tomorrow they will be ready to drill/bore the center holes, as well as start turning the cups/bevels in. I want to be able to turn the bevels on the bronze discs at the same time, so there may be some steps done on them first. I'll need to work out the sequences... Clutches can be engaging work!   

I find citric acid is a good substitute for sulphuric.  It's a lot safer, cheaper, and can be easily disposed of when spent.

It can be bought in bulk online - useful when you're trying to fill a 200 litre tank to immerse a boiler.

As Crueby notes it can add a layer of copper onto steel components if the solution has been used for copper.

Wilf 

Quote from: PaulR on March 17, 2025, 08:18:48 PM

What pickle do you normally use?

For brass/copper/bronze, I like the Sparex pickle, comes as a powder that you mix with water. No where near as strong as other acids, so it wont dissolve you if you touch it (though you want to wash it off, it is still acidic). They used to make a version for use with steels, but that got discontinued. You can use the Sparex on steel, but once you use a container of it on brass or copper, a little of the copper goes into the solution and it will tint the steel to a copper color. So, I keep one container of each (I use PETG screw lid containers, do not use metal containers or lids). I suspend parts into the containers on wire - steel wire for the steel one, copper wire for the copper/brass one).


For some parts, I just use kitchen type white vinegar, 5% solution, from the grocery store. Works great, just slower, several hours vs about 1 hour for the sparex. Cheap, safe, easy to dispose of.

For all parts, after silver soldering, I rinse and wire brush them before pickling, to remove the worst of the soot/flux residues. Sometimes parts need another brushing/rinsing after a while in the pickle, if there was some flux stuck on. After pickling, a good water rinse, and brush or scrub with an abrasive pad.

I usually give parts a wash and rub with steel wool then use vinegar or concentrated lemon juice but yep, it does take some time. I was looking for something safer than sulphuric acid and this Sparex stuff looks ideal, cheers!

Quote from: steamer on March 17, 2025, 10:29:40 PM

Not shown in the model is a ball bearing foot for the contact point.   It will have a 3/4" reamed hole for "Posts" as needed.

I was going to ask about that. I'm guessing a tapered bearing would be preferred for load type but maybe big-ish in diameter vs screw diameter & load & size of contact foot accessories you might want on the bottom?
When you get that far can you post some pics, now I'm more curious about this project.

You can see it now from D.E. Johnsons article.    Don't let me get in the way or your curiosity.

Why are we more curious now?

Good recovery. Did you thread the extension or just make it a tight fit before applying Loctite?

I did think about threading the extension, but ended up by tapping both the crankshaft and extension and inserted a piece of 4BA threaded rod between them, loctiting both ends and the mating faces as I screwed them together. Once its set solid tomorrow, I'll give it a light rub with some emery, but so far it seems to be a smooth join, running true and nicely covered by the eccentric!

I just modified both sides of the flywheel boss and its now flush with the crankshaft, however, I may need a few thou more if the eccentric strap needs some movement.

Phew, what a relief, I had that sick feeling where I was looking at remaking the entire crankshaft from scratch!