Candace

I checked the hook on the 31-20. It doesn't click at all when the bobbin case and bobbin are in. Though I don't have a motor hooked to it at the moment, so I was just turning it by hand. I do see a gap similar to yours that closes as it oscillates. The assembly does have a little play on mine and it does move slightly when wiggled.

Mitch's mom

You can buy 3/8 inch leather treadle belting off of Ebay it even comes with the connecting hook. The seller I bought most of my industrial stuff from was from New York. I'll find his name for you. I had a 31-15 and liked it but I could never get it to run perfectly smooth. There was a catch somewhere in the upper shaft. I tried everything to work it loose. It was a really abused machine that had sat in a damp barn for a number of years. It took me weeks to get the crud out of it. I finally gave up on Q-Tips and gentle cleaning and took it to the car wash and used the pressure wash hose on it without squeezing the trigger. You should have seen the black gunk and crud that came out of it - there was even straw inside it! It was a fun machine to use ans did sew a pretty straight stitch. I eventually sold it. I believe I have a lot of needles of all sizes for it here somewhere; if you are interested I'll make you a good deal on them or maybe a trade.

amcatanzaro

IDK if those needles fit this machine or not. I just know they are in the drawer. There are all KINDS of odd ball items in that drawer some of which do not go with this machine (long bobbins).
I'll get you a picture at some point. I'll bet almost everything in there goes to something else.

Cogito

Thank you Archaic for a thorough explanation. You pointed out some issues I hadn't thought about.
Guess I will scratch the idea of using one for "long arm" quilting. Lol!

ArchaicArcane

Thanks for looking Candace! The noise is really only noticeable when I turn the machine by hand. The motor more than drowns it out otherwise. It sounds like this one is a lot like yours. I will maybe leave well enough alone for the moment.

I reused the hook from the old belt. There were 2 on it. The belt I picked up seems to be fitting well now. I would love to know who you dealt with for sure. I must admit I giggled a little when I read about the pressure washer. Let me know what you have for needles. I have some on order, but I'm always up for variety. And let me know if there is anything that you need, I have some stash of things.

Huh. It looks like that is one of the aliases that the needles that work for the 31-15 go by. At least that's what this google search seems to say:
https://www.google.ca/search?q=71x1+sewing+needles

Seriously, all the designations that the industrial needles have just make my head want to explode. I think it might be possible that one of the most "fun" parts of getting a new machine is the goodies in the drawers.

My pleasure If you were to put an industrial on a frame - weight issues aside - this one probably wouldn't be so bad since it's meant for cloth and tailoring, and apparently on the "light" side as industrials go, according to some articles I read.