Columbia Grafonola - speed control "brake pads" question

[Bad_Photographer]

Hello all,

I'm posting this separate from the "Project" thread I have going. I think I've been able to answer my own question regarding how the brake and speed control levers work. I think the issue that is as follows:

1. The brake lever acts as a "gross" speed control.
2. The speed control lever (the "pointer") fine controls the speed.

I think I've narrowed the problem down to the brake pads. The fine control "works" only if you swing it wide in either direction so that the (fiber?) pads finally come in contact with the governor's rotor. The arm of the brake moves where it's supposed to. It has a tension spring that while it could probably use a replacement otherwise isn't causing any problem I can see.

If you look toward the left of the brake arm, there is a half-round control rod that engages the brake arm which is attached to the speed control lever. It moves in accordance with the "S" and "F" designations on the speed dial. However, the pads do not come in contact with the rotor when you dial the control lever toward "S". It takes a wide movement to the left far past the "slow" end of the speed dial for the pads to finally engage.

If I'm correct in all this and the worn pads are the issue, does anyone know how long those pads should be? I have no doubt I can fashion replacements and probably determine from the speed dial how long they need to be to make contact at the right point, but I'd rather not guess at it. If someone has a similar motor (No. 50 "Favorite" 3-spring) it would sure be appreciated. I'm assuming these are constructed from felt. Leather would likely also work.

The camera also reveals that the governor weights are beginning to "flake" - apparently a well known issue. I'm wondering if I can seal these with poly or latex to retard further flaking.

Thanks!

Mike

[De Soto Frank]

You are correct that the "D" or half-round shaft is the speed-control, and the bronze tab acting on the flat-spring is the official "stop" control (brake).

With motor stopped ( or unwound), and the brake released ( nothing spinning ), the governor disc will probably not be in contact with the felt pads. When the motor is started, and the governor beings to spin, the weights move outwards, causing the springs to pull that spinning disc into contact with the felt pads. The speed control positions the felt pads closer or further from the governor disc.

The "S" and "F" markings on the speed control quadrant are arbitrary, but the center mark should correspond to a platter speed of 78 rpm ( or ( 80 rpm, if you are a Columbia purist).

There is an adjustment for the speed control pointer, which is evident when platter is removed. The fiddly part is that one cannot adjust the pointer with the platter in-place, and spinning at the desired speed.

I usually adjust mine by placing a strobe disc on the platter, getting the speed where I want it, then noting the position of the pointer, removing the platter, then noting/marking the position of the slotted shaft in the center of the pointer hub, loosening the set-screw, and and while holding the shaft still with a screw-driver in the slot, carefully moving the pointer until it corresponds with the center-mark on the plate. Replace the platter and check with strobe disc. Repeat as needed.

As for flaking governor weights, I would just brush the loose bits off, and live with it. Trying to coat them might throw them out of balance enough to cause rumble ? Or, you could get replacement weights from Ron Sitko.

Good luck !

Frank

[Bad_Photographer]

Thanks, Frank. The issue I had was I couldn't imagine those felt brake pads being much thicker than they are. Well, now at least I know it's functioning correctly. I can set the speed with the "brake lever" just fine and I can get it accurate. I'm really pleased with the motor but that's not to say I won't tear it down and clean it completely after I refinish the cabinet and very possibly have the motor mount re-plated.

For electronically produced discs after '25, I check speed by being intimately familiar with Tex Beneke's singing voice (or some other artist - Lucy Ann Polk is good. Edith Piaf, anyone?). I have a good quality turntable that plays my Shellac collection as well - seriously, I can get the speed set correctly that way. Folks in that era had no other ability that their ears. For discs produced prior to '25 - I'm intimately familiar with how Billy Murray should sound. I'm not being facetious but if I had a strobe, I'd probably use it.

Thanks again - your answer cleared the issue up.

Mike

[De Soto Frank]

If you're a masochist, you can stick a bit of paper under the edge of a record, and count the revs while keeping an eye on a watch with a sweep second-hand... I did that before getting a paper strobe-disc...

[Bad_Photographer]

Oh yeah...I've done that! Too funny...I had a turntable some years ago - a Stanton, that played 78s but they don't put strobe markings for 78s on those aluminum platters. I was dubious as to whether it was actually turning at 78rpm and tried that trick. It was closer than I thought.

Thanks again for the info!

[Bad_Photographer]

Oh - and by the way, it wasn't lost on me that I had the Governor action bass-ackwards in regards to the brake/speed felts. It's the governor's rotor that comes in contact with felts that are set to the operator's taste in speed, not the other way around as I'd assumed. Thanks for clearing that up too, Frank. I'm learning something new everyday with this unit. So much different from a Victor 2-spring!

Mike