Need help with a 1956 Singer 301A
 

I have several vintage machines and I like to make sure they are in good condition before I tag and store them. The one causing the issue is this 301. I was testing to see how accurate the 1/4" seam was yesterday and it sewed fine, so I thought I'd clean it oil and grease it before storage. Now today the hand wheel won't turn all the way...It turns about 3/4 of a turn and then stops. I can turn the handwheel the opposite way and it goes 3/4 turn and stops again. I have removed the old grease and regreased and oiled it good in hopes that something would "give". It is still not going past the 3/4 point. I can't see anything and I'm about ready to tag it as a parts machine. Oh, it started this before I took anything apart. Any suggestions are appreciated. Sara

I would:
1. Remove the needle
2. Remove the bobbin and bobbin case
3. Open the door at the left end of the machine
4. Remove the top via the two screws
5. Remove the bottom cover plate

Turn the hand wheel looking at each now visible area and see if anything is visibly binding or hitting something.

If nothing visible I would next drop the motor out and repeat.

Thanks Joe! I removed the motor and still the same. However, after some close investigating, I figured it out. Somehow the thread cutter had got turned towards the side/front and that is what was stopping the needle bar from making a rotation. Now I have to reinstall the motor, which is good, I watched a video to see how to do that for future reference. Plus, the machine is all clean and greased and I will take her for a test run shortly. Again, thank you for your quick response.

I'm glad you figured it out! Something so little, hard to see too.