Title Change: Should You Lap Brass Gears?

[Curt A]

Here's my opinion for what it's worth:
The maker of the video in question, is an avid collector and restorer, along with being a member of this Forum. He may have found a different, better method than one which is considered to be more conventional. He is obviously trying to share a tip that has worked for him and is not trying to cause harm by posting his findings. He is also not suggesting leaving abrasive grit in your phonograph's gear train...

I am opposed to voicing negative opinions regarding unfamiliar techniques, unless you have actually tried them and found them to be faulty through your own personal experience with the suggested method. Quite often, people are opposed to an unfamiliar method for just that reason, it's unfamiliar to them. Personally, I don't know if the suggested method in the video works, but it apparently does or the maker of the video wouldn't have wasted his time doing it...

I wouldn't be afraid to try it, if I had the need, and I appreciate anyone sharing what they believe to be useful tips, since it is obvious that none of us knows everything...

[Django]

Here's my opinion for what it's worth:
The maker of the video in question, is an avid collector and restorer, along with being a member of this Forum. He may have found a different, better method than one which is considered to be more conventional. He is obviously trying to share a tip that has worked for him and is not trying to cause harm by posting his findings. He is also not suggesting leaving abrasive grit in your phonograph's gear train...

I am opposed to voicing negative opinions regarding unfamiliar techniques, unless you have actually tried them and found them to be faulty through your own personal experience with the suggested method. Quite often, people are opposed to an unfamiliar method for just that reason, it's unfamiliar to them. Personally, I don't know if the suggested method in the video works, but it apparently does or the maker of the video wouldn't have wasted his time doing it...

I wouldn't be afraid to try it, if I had the need, and I appreciate anyone sharing what they believe to be useful tips, since it is obvious that none of us knows everything...

I’m sorry that you found my post negative. My intent was to prevent harm to gear trains. I try to mind my business, but this is not a case of an unfamiliar method. It is a case of a harmful method, (lapping soft gears). I don’t think that Flitz will harm the gears because it is not abrasive, and I already said that. Flitz cannot lap anything. I was not questioning the person’s intentions, I was questioning what he was saying, which was that you can lap in the gear train of a phonograph motor, which happens to have soft gears. Questioning intentions is personal. Cautioning that a method can cause harm is not personal.

You don’t have to personally try everything. Sometimes you apply proven knowledge instead.

[gramophoneshane]

I must admit I'd never heard the term "lapping" before reading this thread, so I googled the definition/ explanation, and after reading through the Wikipedia entry, I came to the conclusion it's probably not a good application to apply to just any phonograph motor.

I might think about trying it on a replacement gear from a different motor where both meshing gears were steel and had very different wear patterns on the teeth, but only then if they were particularly noisy or tended to bind due to burrs or raised areas on gear teeth next to worn areas on the gear.
Generally speaking though, I think it's not going to make much sense removing metal from the surface of gear teeth to take up play between gears or quieten a motor.

I'm not dismissing the idea simply because I haven't tried it, but after being armed with just a little bit of research into the process, I feel it may well do more damage than good in most cases.

I suppose the best advise to anyone thinking of trying this, or any other collector's tip for that matter, would be to take some time to do some reading first, from a couple different sources if the first seems a bit iffy or for consistency of information, then make up your own mind.

[Django]

I changed the title to concentrate on a discussion about lapping gears, and whether or not to. The original title was to make the point.

There are compounds that are made for running in gears or soft bearings. These materials do not embed and will break down and become harmless, but they will wear the gears as they break down. Lapping compound on the other hand contains a hard abrasive that will embed itself into a soft Brass gear. Anything that is designed to run something in will remove material and make an already sloppy gear train sloppier. It may make it more quiet and break it in more quickly, but it will cause additional wear. If you have a "tick", then you are probably better off locating the source and fixing the source of the problem, rather than wearing in a whole train of gears. If you have gears that are not meshing properly, adjusting or replacing are the best options.

The force on a phonograph motor's gears are low. The pressure per square inch where the teeth mesh is extremely high, (the force is concentrated over a very small surface area).

Please think about it before applying an abrasive to your gears. If the goal is to wear them in quickly and easily, then this may work for you. You might want to inspect the gears instead and make sure that they are not worn or damaged and replace or repair as needed. You can isolate the offending gears by removing either what drives or what is driven by them, (remove the spring barrels). Watch how they mesh. Are there tight spots? is there a vibration? Are they engaged well? Do they feel smooth? Adjust, repair or replace accordingly. You may even find that you have a bent shaft or a gear that is not running true. That is my advice. The other advice is to research exactly what an abrasive is to be used for and to follow any instructions exactly.

As I have said repeatedly, I do not think that the person in the video is causing any harm by applying Flitz to the gears because it is actually a cleaner and not an abrasive. The thing that concerned me was the term lapping, which causes wear, which I believe we are trying to prevent.

[mick_vt]

Just my 2cents - Flitz is a polish - polishes have abrasive in them, albeit fine ones - it's how they work

Will this abrasive embed and do damage? I am not qualified to say

[VanEpsFan1914]

I clean mine with a toothbrush dipped in kerosene and have not bothered to polish the teeth of the gears. The old graphite that has worked into the brass from years of running is probably good for them.

The only parts of motors that I polish are spring barrels, governors, and the frame if it needs a good scrubbing. So far so good--they aren't pretty but they sure do run well.

[Daithi]

I don't think its a good idea to lap soft alloys since the abrasive embeds in the alloy and continues to wear the parts long after the lapping compound is removed.
I think flitz is an abrasive albeit a very fine one.