Columbia Grafonola - speed control "brake pads" question
Posted: Fri Apr 01, 2016 12:35 pm
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
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