Phonograph Motor Basics
This particular motor came out of a very early Sonora Phonograph (c. 1910). It's design is typical of the Swiss motors found in most mechanical Sonora phonographs. The frame is in two parts and is made from cast iron. The posts are part of the upper casting. The small "U" shaped projection on the upper casting is the pivot point for the speed regulator arm. This motor obviously hasn't been touched and is in the exact condition in which it was found.
Motor - Front View
1. Pawl; 2. Ratchet Gear; 3. Spindle.
The pawl and ratchet gear are what allows the springs to remained wound. This is also where the crank attaches to wind the springs. The pawl is held by a spring that forces it into the teeth of the rachet gear. This allows the motor to be wound and also prevents it from unwinding.
This is a close up of the worm gear. Original owner's manuals for Sonora Phonographs recommend putting a dab of petroleum jelly on the worm for lubrication and to keep the gear pair quiet (see lubrication notes at the bottom of this page.
Governor Assembly - close up
Bottom View with Maker's Mark (note hand written inspectors number)
All gearshaft end bearings should be lubricated with a light machine oil. I recommend using a 'sewing machine' type oil as opposed to a heaver general purpose lubricating oil. The lighter oil penetrates a bit better. When I say 'well lubricated' I mean just enough oil to do the job. I say this because oil is a dust magnet and you don't want dust accumulating where it can act as an abrasive. Adherence to firearms lubrication techniques is a good idea where metal-to-metal contact in involved (this is the "enough but not too much" rule). More about this when I talk about gears.
The end shafts of the governor and the leather pad that rides the governor disc should also be lubricated with oil.
Gear teeth should be lubricated, but there's four schools of thought about this point:
1. The first school of thought says that you should use grease (like white lithium grease, gear grease or petroleum) and not oil- this is the school of thought I adhere to on this particular subject if the gears are sufficiently noisy and need some quieting down.
2. The second school of though involve using oil on gear mating surfaces. I do not recommend oil for lubricating gear teeth because, as I said before, oil is a dust magnet. Dust will eat up the mating surfaces of gears. Grease is better at isolating airborne dust and moving it away from the mating surfaces.
3. The third school of thought (an on which I also recommend if your gears are in especially good condition and gear noise is not a problem) involves using a dry silicon lubricating spray.
4. The fourth school of thought (and a fairly spooky one at that) involves using no lubrication at all on gear mating surfaces. There is a method to this madness but don't try this at home, folks. I don't recommend this last school of thought at all.
be sure to oil the bearing surfaces of the pawl and ratchet and grease the ratchet gear while your at it.
On an interesting side note, if you closely examine the gears teeth on a well-used phonograph motor, you will find that when brass gears mate with steel gears, the steel gears tend to wear out first. There's a reason for this: when grit is involved where brass and steel meet, the grit tends to get embedded in the softer brass. When this happens, it acts like sandpaper on the steel gear and wears the daylights out of it. Again, grease doesn't attract airborne dust like oil tends to.
The spindle gear - the bottom cap should be removed every once in a while and cleaned with a solvent along with the bearing end and re-greased with a good gear grease or white lithium grease. You also want to put a drop of oil on the bearing end where it passes through the casting. At the top side of the spindle bearing there is usually a felt dust seal. Put a drop or two of oil on that. You also want to put a drop of oil on the top bearing (where the spindle passes through the casting). Always use grease in the cap-end of the spindle bearing - lots of it.
Worm Gear - put a liberal slathering of petroleum jelly on the worm gear. It keeps it lubricated, quiet and happy.
Some brands of phonographs used 'fibre' gears ('non-metallic', as a general description). Avoid getting grease and oil on any pair of gears that involve a 'fibre' gear. It tends to damage the fibre gears.
Springs - if they thump and bump, carefully and gently wind your machine up full and let it play down a couple of times. If this doesn't cure the problem, then you have to open up the spring barrels and add some petroleum jelly (you can mix in about 10% by volume No. 2 graphite). Word of caution! If you don't know how to work with springs, send the motor off to a phonograph repair service or have someone do it who has done this type of work before. You can get hurt badly if a spring lets loose. I'm talking really nasty hurt bad. Just ask around with phonograph collectors and listen to the horror stories.
Frequency of lubrication.
If you play your machine a lot like I do (about an hour or more each day on average) you might want to do your lube routine on the motor about once a month where oil is used. On parts that you use grease, just check to see that the grease is in good shape - you don't need too much, just enough to lube the gears. If you use spay silicon lube, then spray away to your heart's content on the gear teeth.
Be sure to carefully wipe off any excess oil or spent grease with a lint free cloth (lint is very abrasive, by the way). If you even suspect that there is any grit crunching around, have the motor cleaned and re-lubricated.
And I'm not joking about springs.
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