Low insulation puzzle: what's this?

[Lucien Nunes]

Damp here this morning, and the insulation resistance on a piece of workshop equipment seemed a bit low. I could influence the reading by pressing my hands against the outside of one of its controls. That, and the fact it is getting a bit stiff to operate, show that it's time for this control to be stripped down and cleaned. Metal deposits and dirt build up inside over the years and cause leakage.

The main core of the thing consists of 36 parts threaded onto a shaft. I slide them onto a long screwdriver to preserve their order and orientation as I take them off. Then as I clean each one I put it back onto the shaft.

What equipment is it part of? The maker's name will be familiar but the equipment itself probably not so much. A couple of people here will get it in one. Give the others a chance.

 

[DPG]

When you said about the items on the shaft I was thinking some sort of cam operated programmer. But the photo doesn't show one.

 

[Lucien Nunes]

Definite similarities though. That pic shows some of the conductive build-up on a moving part. It rotates around this part:

 

[DPG]

Some sort of slip ring then? A rotating table?

 

[Lucien Nunes]

Nine sliprings, if you want to call them that.

 

[DPG]

So transferring power to a rotating part. Nine rings to cope with the amount of current needed to be transferred?

 

[Lucien Nunes]

Nine because there are nine separately movable subassemblies. Hub, fixed contact (slipring), rotor and moving contact.

 

[DPG]

Tricky. Is it a machine tool of some sort, or some obscure test rig?

 

[Lucien Nunes]

Measuring instrument. Hurry up, I'm on section 8 of 9

 

[littlespark]

Is it the Enigma Machine??

 

[Lucien Nunes]

Also lots of similarities.
Section 9's wheel and moving contact cleaned

 

[DPG]

Struggling. If nobody guesses can we have another clue?

 

[Lucien Nunes]

Inserting the contact rods.

 

[DPG]

Still looks like a cam programmer to me.

 

[littlespark]

Some form of calculating machine.

 

[Lucien Nunes]

Operated manually. Nine 1-pole 10-way switches in a matrix. Dial each of the nine wheels to a setting from 0-9.

Bear in mind that it is a piece of equipment that I actually need to use. I don't have a substitute. And that insulation resistance is important.

 

[littlespark]

So thats how lucien types up his threads?

 

[Lucien Nunes]

I did make a ZX81 input device consisting of three dials and two buttons, when my membrane keyboard gave out in the middle of a project.

 

[Lucien Nunes]

Detent springs adjusted and shaft nuts locked with lacquer

 

[timhoward]

I did make a ZX81 input device consisting of three dials and two buttons, when my membrane keyboard gave out in the middle of a project.

The ZX81 keyboard wasn't the finest piece of engineering ever! Had that ribbon cable in and out many times....