Hi again,

Just curious, what do you call the heavy (lead?) wheel which is attached to the tuner dial neck? It looks like it's about to break into a dozen different pieces, so I might need to replace it.

It's purpose eludes me other than to possibly give the tuner dial a bit of centrifugal force to make going from one end of the scale to the other a little easier. The dial station window is about the height and length of a standard ruler and the dial is the size of a 20c piece, so it takes a while to go from end to end...

Thanks in advance.

Those die-cast wheels are usually made of pot metal (aka 'muck' metal) and are very fragile. Yes, they are to give the tuning mechanism a bit of heft. It can be glued together, although a replacement is a better idea if you can find one.

Cheers GTC,

I thought that might be the case. Had no idea what it was made of though. maybe I could fill the massive cracks with epoxy or something.

I don't like my chances of finding a replacement. I did a google search, but don't even know what they're called, so it reduces the effectiveness of a search.

JB Weld is an excellent epoxy for metal repairs.

https://www.jaycar.com.au/j-b-weld-epoxy/p/NA1518

Thanks.

I actually have some JB floating around. I've give it a go.

If it comes to it, I can probably make a cast from it (It's still in one piece presently) and have something made to replace it.

Its maybe called a flywheel.
Being zinc it has a bit of weight to give it some inertia, so you would need to use brass or steel to give it equivalent weight.

It is called a flywheel. Most of the ones I recall seeing were made from lead. You could easily cast a lead one yourself.

Make a plaster cast and use plumber's lead or flashing. If the old one is lead it will provide most of the material.

Then drill the spindle and lock screw holes.

I had a tuning dial wheel made from muck metal disintegrating badly.
I soaked the lot in epoxy resin and made it whole that way.
Quick spray with alloy paint and it looks like new.
Fred.

Thanks for all the help everyone. I really appreciate the input.

That is "pot metal" aka "Die cast" of which there are a few differing alloys. Principally the issue is a large quantity of Zinc and metals that are known to exfoliate & create whiskers: That is literally what blows it apart.

Lots of parts were made from it as it could be cast with little heat. There has been success & there is an example on the American Radio Forum where new parts have been printed. I have a turntable from a Philips here where they made a large proportion of the Motor gearbox out of it and it has broken apart.

What you have in that Inertia wheel is a Flywheel. Epoxy High strength I have found the best as it soaks into the pores. However, there is such a thing as "stuffed" and beyond redemption. Normally it is near impossible to get good one, or it off a shaft. I may have one in a scrap set? So it boils down to Araldite, or New if you can get one on, or off a shaft, or my normal: Get an idea of the weight, diameter & width and turn up a new one.

If you use insulation tape around the outside, that becomes a removable former for the periphery. That also works on valve base to envelope bonding.

Marc

If the zinc of the flywheel is a lost cause,but its axle is OK, it may be possible to replace the zinc with a number of large steel washers of the right diameter with the axle through the centre, all held together with araldite.

Much simpler here to go scavenge a lump of Aluminium, or something & feed it to the Lathe, on the odd occasion you can turn the shaft & wheel as one bit. Even extension shafts, can be turned as one bit, & replacements for broken dial pulleys have happened here. Even the replacement ball & socket on the tractor's throttle is home made.

Marc

Noted there is one minus shaft in the engineering shed.

Marc