What’s causing the erratic speed on my Edison B80?

[cheryla]

Rebuilt everything but once I put it under power by putting on a record I get erratic speed. It speeds up and slows down. I’ve adjusted the governor, adjusted the belt tensioner, cleaned all the bearings. Any ideas? I have rosin for the belt coming today.

[rodpickett]

You should ensure you have lateral movement as well as vertical movement of your stylus / weight.

[fran604g]

In addition to Rod's great advice, what condition are the gears? Do the fluctuations occur rhythmically? If so, is there a point in which a slightly out of round gear, or several teeth on any gear that are damaged, and causing binding?

A slightly bent gear shaft could also cause binding every rotation of that gear. Watch the gears and note any that aren't running true to its mate(s).

Just throwing a couple possibilities out there.

Best,
Fran

[cheryla]

Thanks for the advice. Under a magnifying glass I can see a few burrs on some of the gear teeth. I built a jig to hold the gear and will attempt to file the burrs. If not I’ll have to replace the gear.

[gramophone-georg]

Every speed up/ slow down issue I have ever encountered came down to governor springs. That said, I have no experience specifically to the B-80.

[CarlosV]

The belt may be skipping. Try to roughen it with a fine sanding and check the surface of the wheel that interfaces with it, it has a cork layer that could be contaminated with oil or dirt.