Another Singer 31-15 issue

[BruceWampler]

I used to own a 31-15 that was motorized, so I know the capabilities. Hopefully this is a stupid question, but here goes. I purchased a machine someone had taken home from a factory that used treddle machines, who knows when. It had a 2 extra aftermarket cast bobbin carrier holders. It was missing a nut on the bottom, and everything that could be tightened, was loose.  It had a home needle in it, and the drawer was full of vintage home needles. The bobbin hook was rounded and wouldn't catch the thread, so I ordered a new hook and carrier, and installed the correct needles. (Yes, I know which direction to put the needle in). The timing looks right with the exception of when I install the cast piece and the bobbin carrier group the machine seizes up. Loosen the retaining screws, and the machine functions fine, but the needle drags across the edge of the bobbin hook. Here's the question. Does anyone know the correct way to adjust the bar so it doesn't jam the bobbin hook into the iron carrier? I see a set screw where it can be rotated around, but I need it to be just a hair shorter, away from the bobbin carrier group. 

[trash treasure]

Have you checked that the needle bar height is correct?  It may have been lowered to use the home machine needles.

Or maybe I'm misunderstanding the problem ......

[Cascabel]

While you are putting things right, be aware that Singer did NOT use standard threads on their machines, so hardware store screws and nuts will not work.  They had their own proprietary threads on their hardware.  You will need to get screws, etc. from dealers in Singer parts, or have them custom made.

[BruceWampler]

5 hours ago, trash treasure said:

Have you checked that the needle bar height is correct?  It may have been lowered to use the home machine needles.

Or maybe I'm misunderstanding the problem ......

Wrong direction. The bobbin race unit is too far forwards. The needle height is fine.

34 minutes ago, Cascabel said:

While you are putting things right, be aware that Singer did NOT use standard threads on their machines, so hardware store screws and nuts will not work.  They had their own proprietary threads on their hardware.  You will need to get screws, etc. from dealers in Singer parts, or have them custom made.

Learned that the hard way. I now have a handy little thread pitch gauge and a direct line to the local Singer parts dude.

[BruceWampler]

A big thanks to Airplane Guy who sent me a copy of the Navy Manual.

 

[iknowit101]

Not sure if you have seen this video,  this guys is very good explaining thing, good luck.

 

 

[BruceWampler]

Yep, watched it. I didn't see him cover what I need. I need to adjust the shuttle driver/oscillating shaft inwards. The needle is rubbing the side of the hook by about 1/16 of an inch.  The adjustment of the needle/dogs is nicely explained, but that's not what I need.

[cdthayer]

It sounds to me like the new replacement casting is just a tad thinner than the old original race, or the new hook is just a tad thicker than the original hook.  

Have you tried mounting the new hook with one or all of the old cast races?  If they also bind the machine up, I would think that the new hook is too thick.  If so, you might try making a shim of some sort to keep the casting set out just a little when tightened down.

CD in Oklahoma

 

[BruceWampler]

I had to try it, to realize it all needs to move inwards, not out. 

 

Edited June 9, 2019 by BruceWampler

[cdthayer]

Shimming the race out may solve the binding problem, but the hook may still hit the needle without some shimming behind the hook as well.

I’ve had a real problem trying to make the new replacement parts work on old machines, and in some cases, just had to throw them away and find usable parts from an old machine.

CD in Oklahoma

 

[BruceWampler]

figured it out. I had to shim the oscillating rod all the way to the right side of the machine to keep it from binding up the shuttle hook. Waiting on a new shuttle driver carrier hook (can't remember the name). Hopefully then all will be well.