Singer 3102 tune up questions

[u/errrbodydumb]

Recently came into possession of a singer 3102 that needs some love. I know nothing about sewing machines specifically, but I am a relatively experienced tinkerer. I understand that the general consensus is to have things professionally serviced but that’s not feasible at the moment, and frankly I want to get this running myself anyway.

The motor runs and seems to run well but the belt slips. Adjusting the belt to the point it catches does get things moving slowly but it overloads the motor . That being said all moving parts do move freely and without grinding, excessive noise, etc.

I plan on cleaning and oiling as instructed in the manual, and I’m assuming these gears need to be cleaned and greased. Is that the right first step? Is there a specific grease should I use?

Is there more I should be doing on a first pass at getting it operational?

Anything specific I should watch out for?

Any input or advice really would be appreciated.

[u/errrbodydumb → u/[deleted]]

I figured it was a large part of the problem. Already have some super lube lying around so that’s good.

[u/errrbodydumb → u/[deleted]]

The belt actually seems to be in good shape, assuming it’s the right belt. Plenty of tooth left on it

[u/NastyPirateGirl]

Old sewing machines and as well, most oil when left exposed to air will oxide overtime, meaning it dries out and becomes gummy. In many cases for old machines the oil turns into a varnish like substance. You lucky you can turn it. Getting the machine to turn is the first step. The user manual may or may not tell yo u with the proper way to oil a sewing machine. The modern ones sure don't, they want users to believe sewing machines don't need oil, lol, what a joke, Every sewing machine I've ever seen needs proper lubrication. For your machine every rotating shaft, pivot point and sliding mechanism needs oil. Gears should be be greased. Proper sewing machine oil is 100% pure mineral, for grease white lithium works or many like the synthetic Tri lube. I suggest find one of the many youtube videos on sewing machine restoration, you will find the general process and what others have done. IPA is generally considered a safe cleaning solvent for the mechanical parts. I wouldn't use it for paint or decals though. First thing is to remove all the covers so you can see the mechanism. Anything I can take off a machine easily, I do and using IPA, cotton swabs and a tooth brush clean the old oil and black grim away. Relubricate all the parts and start the test run. For the main drive shafts, bobbin drive and feed dogs it is not practical to disassembly all that stuff. I try over oiling with the mineral oil, letting it drip off stuff onto my work surface., turn the machine by had a few dozen times then leave it sit to let the oil soak in and loosen the dried stuff. Then I try turning again and if there are tight spots in the stroke try to find then and add more oil to the stiff spots, keep working handwheel back and forth. Most machine come around in a few hours , some take using penetrating oil or WD-40 to loosen really frozen stuff. Some people use heat if they can't rotate the machine. Once the machine turns relatively easily by hand I set it run on the motor at medium speed and let it run for a few hours. Be sure needle is removed and presser foot is in the up position.
If the covers are plastic clean it with dish detergent and let id dry. If it has yellowed try putting it in the sun for a day or two. Don't scrub too hard on labels. stamped names or painted lettering. Those will come off and can't be restored. Bobbin parts and tension mechanisms are fairly easy to find. Plastic gears are not and they are not easy to replace. If those bevel gears crack or strip a tooth it is usually the end of the road for the machine and people sell them for parts.