Columbia Harmony Portable Wobbly Turntable

[LynnB]

My new-to-me Columbia Harmony Portable No 2 has a wobbly turntable. The spindle seems fine. When I tighten the rearmost of the three screws that connect to the motorboard it shifts diagonally about a quarter of an inch.
To be honest I have no idea what I’m doing. But I’m willing to learn.
Thanks

[Curt A]

Not sure what the problem is, but it might just need an additional spacer between the motor and motor board. Also, make sure that whatever you have it setting on is level...

[LynnB]

Thanks. Yep, the workbench was level as well as the phonograph itself. Just the turntable is off.

[Lah Ca]

On one portable I had to replace all the rubber bushings/grommets/washers that dampened the motor vibration. These were between the motor and the motor board, the flat surface of the machine under the platter. When, in the 1920s, they were first installed they would have been quite rubbery, but one hundred years or so later they were as hard as rocks. The platter actually rubbed against the motor board. I eventually made new ones out of natural gum rubber sheeting, With these in place I could go around and adjust the three mounting screws until platter clearance was even all around and the motor was still mounted securely. The new ones were soft enough to compress when screws were tightened down but springy enough to hold the motor secure against the motor board when screws were backed off for adjustment. With the old hardened ones, I could not adjust things properly; they were too hard and too flat -- no spring left.

By "wobble," do you mean that the platter actually wobbles rather than it turns consistently but just in a different plane than the top of the gramophone? If you mean that it turns consistently but not in a plane parallel to the motor board, then replacing the rubber bushings/grommets/washers will probably allow you to adjust things.

If by "wobble" you mean that the platter spindle wobbles in its bearings, then there is probably a more serious problem.

[LynnB]

So, the spindle does not seem to be wobbly, just the platter when it turns.
Do you mean these rubber grommets under the screws on the top side of the motor board? The ones in my photo?

[Lucius1958]

So, the spindle does not seem to be wobbly, just the platter when it turns.
Do you mean these rubber grommets under the screws on the top side of the motor board? The ones in my photo?

If the spindle is not wobbly (which you can check by removing the turntable, and feeling the spindle as it runs), then the turntable is not sitting level on the spindle.

Depending on how the TT fits on the spindle, you may have to find the low side, and shim it until it's level.

- Bill

[LynnB]

Thanks. I ran it with the turntable off and I even put a straightedge alongside the spindle and it was straight as an arrow.
With a level on the turntable it looks to be low toward the front and the right hand side (like this ).
Any advice on how to shim, what to use, etc?
(BTW, sorry if I ask simple questions, I’ve never done anything like the before so I’ve got a whole lot to learn.)

[Lah Ca]

If the spindle is perpendicular to the motor board from all sides and it does not wobble in its bearings, then the problem lies elsewhere. Not the bearings. Not the mounting of the motor to the motor board.

How firmly is the platter mounted on the spindle? Some platters are press fit on a tapered spindle and it takes a fair bit of pressure to get them on and off.. Some have retaining devices like a C clip. Yours looks like it would have had a C clip.

Look at the bottom of the platter. Is the part that the spindle goes into in good condition? Not bent, worn excessively or otherwise damaged?

Is the platter itself flat?