Big Bobbin Hot-Rod Upgrade for Singer 111w155

[Nix]

Just finished a major hot-rod modification to my 111w155 by upgrading the smaller stock G-class bobbin and hook assembly setup to the very large U-class Juki 563 bobbin and hook assembly.

As noted in this thread and its linked video, the upgrade requires milling the stock hook saddle to accommodate the larger Juki 563 hook and bobbin. The upgrade also requires swapping out the stock thread take-up lever with that of a Juki 563. In addition, the bobbin case opener should be changed to that of a Juki 563. All of these parts are readily available at various quality/price points.

Still, this is a project that is not for the faint of heart. The stock hook saddle assembly must be milled down about 1/16-inch, including the reliefs for the bobbin case opener crank assembly.

The cast iron hook saddle machines well, but you need to be extremely careful in fixturing it to your milling table. I used a couple stout milling clamps/hold-downs and a small machinist jack on the outrigger mount extension of the saddle to hold everying steady. Once mounted to the milling table, I proceeded very slowly to mill all of the necessary pockets. The bobbin case opener needs to be clearanced for the larger hook assembly as well.

Assembly, as they say, was the reverse of disassembly, but with one sticking point. The new Juki 563 bobbin case opener didn't come anywhere close to working in its stock configuration. However, with a little bit of careful heating and adjusting, it now performs perfectly.

Bottom line, while extremely fussy to carry out, I'm really happy with this modification to my 111w.

The pics show the new hook assembly with a G-glass bobbin inside and a U-class bobbin for comparison.

Nix

 

[DieselTech]

Nice work. I can only imagine the obstacles you went thru to get your machine the way it is now. 

Edited September 7 by DieselTech

[kgg]

That took effort. Not for the faint of heart. Nicely done.

kgg

[Nix]

Thanks. I have to say it was a relief to have this machine stitching again (and it worked superbly before the upgrade).

I'm pretty sure my 111w is pre-WWII production or shortly thereafter, and it's definitely seen hard use. I've never had the machine's top or bottom apart to the extent I had it in pieces during this upgrade. Even so, no fastener, collar or screw really put up a big fight in terms of disassembly to change out the take-up lever and the hook and hook saddle. It's amazing the build quality of these old machines and the level of fit, finish, hardness and parts choices.

Nix