Can I make this early Victor motor run smoother and quieter?

[startgroove]

Lori and I recently acquired a piece with a Victor VI motor. It is an early example with the bevel gear drive motor, aka spur gear motor. That style motor is notorious for being noisy, and this one was no exception. It also had a hiccup in the speed regulation, causing an irregular pitch change several times per revolution. It sounded awful! Surely it could be made to sound better, I reasoned, and so the challenge began. In addition, the motor would barely run through a 12 inch disc before it began to drift off speed.

After removing the entire motor from the motor board, I disassembled the motor down to all of its’ parts except for leaving the spring barrel intact as one assembly (it went through the usual cleaning and re-greasing procedure previously). The first picture below shows all of the parts laid out, after a thorough degreasing and cleaning.

Next, I examined each and every gear carefully, and with a magnifying glass. I suspected that either uneven wear, or a burr, on one of the gears was causing the stuttering speed. I was pleased to see that all the gears had very little wear on them, including the governor gears. However, to my surprise, I discovered that the governor drive gear was loose on its’ rivets. See the second picture. A little peening of the rivets tightened it up. The motor was reassembled and tested. The result being that the speed was far less uneven, yet it still had a jump in speed about every fourth revolution.

After a second disassembly and close examination, the larger bevel gear showed several teeth in a row that had been dinged at the outer edge. It appeared that gear had taken a hit by something hard, perhaps had been dropped in a previous attempt to repair the stuttering speed. A jewelers file cleaned up the burrs and after polishing on the buffer, the motor was reassembled and tested. This time the motor ran smoothly and consistently. There was an annoying constant humming coming from the motor, loud enough to be easily heard before the sound started from a recording.

Another close examination showed that the sound was coming from the governor drive gear and driven gear group. The noise varied as the turntable was loaded, and seem to diminish with time. By adjusting the height of the driving gear on the turntable shaft, I was able to reduce the noise somewhat. In addition, by adjusting the engagement depth of the driven gear (on the governor shaft) I was able to reduce the noise a little more. In all, I think the noise reduced by about half, but nothing I did diminished it completely. The last thing I tried was to lap the gears together. After applying the lapping compounding and running the motor for three full windings of the crank, I removed the gears and cleaned them up.

Upon the last reassembly, the motor was lubricated again, and as needed. See the last photo of the motor installed on its board. The last test proved that much improvement had been made. The humming noise from the motor had been reduced to about one third as much by all of the procedures, and the motor ran through two 12 inch recordings before the speed began to slow.

As a final test, I ran the motor until the speed began to falter, then stopped it. The crank was turned 35 times (it could have been turned more, but I did not want to go until the crank would not turn any more, for fear of stressing the ends of the springs) and then the motor was started and a record was played with a loud tone needle installed in the reproducer. After five minutes and thirty-seven seconds, the motor speed began to slow. This proved that optimum performance and quieting had been achieved.

[soundgen]

Can you do some for me ? 5*

[AZ*]

Interesting information. Thanks for sharing. I'm glad you solved your problem. I know the idea of lapping gears has been controversial when discussed in previous threads.

I own several machines with these motors. They all seem to run OK and keep speed, but they are a lot noisier than the later models. I consider than part of their "charm."

[startgroove]

soundgen, PM sent.

AZ, Yes, there is quite a controversy about lapping gears. I trust it, as I have been doing it for forty years or so. However, this was the first set I lapped after the thread here discussed that some of the lapping compound can get stuck in the gear teeth. I was wary of doing it again, but I wanted to know. After lapping, I examined the brass teeth very carefully with my magnifying glass and I could not see any particles in the surface metal. I did not even see the abrasions that I expected would be there after lapping. Probably because the lapping compound was a finer grade, or maybe the strength of magnification was too low. Anyway, since I plan on keeping this motor for my lifespan, it won't impact anyone else. I will check every couple of years to see if there is any premature wear. Although, at the same time, it is not likely that I would play this piece every day for years, like it would have been back in the day. Cheers, Russie

[phonojim]

Very nice job. I thoroughly clean my motors as part of an overhaul, but just WOW! What did you use for lapping compound? I have a couple of motors that could use that treatment.

Jim

[phonojim]

Very nice job. I thoroughly clean my motors as part of an overhaul, but just WOW! What did you use for lapping compound? I have a couple of motors that could use that treatment.

Jim

[startgroove]

Jim, I order it from Ebay. I just checked and found several grades and brands there. The finest finest grade is 1000, but I checked mine and see that I used 320. It comes as course as 80. Check this link: https://www.ebay.com/sch/i.html?_from=R ... sacat=6028

Cheers, Russie