Amberola V Governor Issues Solved - movies added
Posted: Mon Jun 26, 2017 10:07 pm
I thought you might be interested in some "tear your hair out" problem solving I just finished. I bought an Amberola V in April of 2016, a nice mahogany one with a good finish, good paint and excellent plating. I went through all of the normal cleaning and lubrication that I do with a new-to-me machine. It played well but then I noticed a knocking sound which I traced to a cracked governor drive gear. The first thing I discovered was that Ron Sitko does not carry those gears for the V. Then, a very kind forum member offered to make me one, which he did, and the knock was cured. Then I noticed that when I released the brake, the governor would go into a wild flutter, however if I released the brake slowly, it would run properly. I went through it with a fine toothed comb several times; checking the springs, weights, tightness of the screws, endplay and everything else I could think of. After each session with more fresh oil on the pads it would work correctly for a couple of days after which the problem would return. I eventually found two problems: one was a spot of corrosion on the contact surface of the governor flywheel. It was relatively deep with rough edges. When the governor moved into contact with the pads, they would momentarily drag on the bad spot and cause the fluttering. I don't think this would be very likely to happen with a single governor pad, but it makes the yoke bounce and cause the flutter. I disassembled the governor and polished the flywheel surface with wet or dry sandpaper, working my way up from 250 grit to a final polish with 1200 grit.
The other problem was the pads themselves. I removed the yoke and took a good look at the pads and saw that they were so hardened from old dried up oil that they could not hold any fresh oil - it would just sit on the surface and eventually be thrown off and the problem would return. I carefully scraped the contact surfaces of the pads, then soaked them in naphtha for 2 or 3 days I final soaked them in denatured alcohol for a couple of hours then let them dry completely. I still needed to do a little more scraping. After the cleaning they soaked up the oil like sponges. After final adjustments the machine has been running fine for the last few months.
I have never seen this kind of problem before, so I hope my experience will be of help to someone else.
I just attached 2 movies which show the governor operating with flutter and normally so you can see the problem in action.
Jim
The other problem was the pads themselves. I removed the yoke and took a good look at the pads and saw that they were so hardened from old dried up oil that they could not hold any fresh oil - it would just sit on the surface and eventually be thrown off and the problem would return. I carefully scraped the contact surfaces of the pads, then soaked them in naphtha for 2 or 3 days I final soaked them in denatured alcohol for a couple of hours then let them dry completely. I still needed to do a little more scraping. After the cleaning they soaked up the oil like sponges. After final adjustments the machine has been running fine for the last few months.
I have never seen this kind of problem before, so I hope my experience will be of help to someone else.
I just attached 2 movies which show the governor operating with flutter and normally so you can see the problem in action.
Jim