Can I make this early Victor motor run smoother and quieter?
Posted: Mon Jun 29, 2020 12:50 pm
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.
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.
