Singer 108WSV36

[Constabulary]

6 hours ago, brongle said:

so it should able to drive a swinging attachment plate. 

yes, there is a short pin on the underside of the swing plate that goes into the slot in the feed dog and the moving feed dog governs the swing plated.

7 hours ago, brongle said:

Any idea what the slot engages with, if anything? I couldn't feel much in there with the screwdriver, and the below is definitely a bit simplified. One thought that comes to mind is that it might act as a sort of flexure brake, expanding slightly against the inside of the driveshaft when you tighten it to keep it from shaking loose and reducing the stitch length as you sew.

 

It engages with nothing. You can put a screw driver in the slot and with a little twist you can widen the slot a little bit so you have more friction between the spindle and the inside of the drive shaft and that IMO is for holding the spindle in place otherwise it could probably move and alter the stitch length. That what I think.  😉

[brongle]

13 hours ago, Constabulary said:

It engages with nothing. You can put a screw driver in the slot and with a little twist you can widen the slot a little bit so you have more friction between the spindle and the inside of the drive shaft and that IMO is for holding the spindle in place otherwise it could probably move and alter the stitch length. That what I think.  😉

Gotcha! That makes a lot of sense. 

[friquant]

On 3/1/2026 at 5:52 PM, brongle said:

Re: your (double) note there - do all rotary hooks rotate twice per stitch cycle? All three of my machines definitely do. Didn't realize you could end up grabbing the thread twice, but that makes sense. 

I think modern rotary hooks all rotate twice per stitch cycle. The ones I've seen accomplish this using gears. But imagine a machine with a rotary hook that uses only eccentrics to accomplish motion---those are the ones that I suspect only rotate once per stitch cycle.

As a reference here is a reply to one of my posts on another forum in which the collector Unknown Artist states: "rotary hooks (Wheeler Wilson system) run smoothly. They are wear-resistant, fast, and reliable, but louder than double-rotary hooks. (Pfaff)". 

That was the first I had heard anybody mention single or double with the word rotary. I would like to obtain a single-rotary because I'm curious about the mechanism. Even if it's a domestic machine. I suspect that the White Rotary from a hundred years ago is single rotary, so I have my eye open for one of those.

[brongle]

On 3/3/2026 at 12:01 PM, friquant said:

I think modern rotary hooks all rotate twice per stitch cycle. The ones I've seen accomplish this using gears. But imagine a machine with a rotary hook that uses only eccentrics to accomplish motion---those are the ones that I suspect only rotate once per stitch cycle.

As a reference here is a reply to one of my posts on another forum in which the collector Unknown Artist states: "rotary hooks (Wheeler Wilson system) run smoothly. They are wear-resistant, fast, and reliable, but louder than double-rotary hooks. (Pfaff)". 

That was the first I had heard anybody mention single or double with the word rotary. I would like to obtain a single-rotary because I'm curious about the mechanism. Even if it's a domestic machine. I suspect that the White Rotary from a hundred years ago is single rotary, so I have my eye open for one of those.

Oh that's interesting! I wonder what makes them louder? 

 

Made some progress on the timing belt today:

Printed this today in Priline shore 98A TPU. I'm expecting this to work, given that a cloth belt with staples as teeth also works, but if it gives me issues, I can remove some of the clearance in there on a revised print to tighten up the engagement. 

 

I also found that the bobbin basket is intermittently binding up in the race. I ran the whole hook assembly through the ultrasonic cleaner, then each part individually after enough gunk came off to reveal the screws holding it all together. That didn't seem to fix it, and that leads me to believe that something is ever so slightly distorted, as there are no visible burrs or dings that would raise material. My intuition is to blue it up and find the contact patches, then remove the high spots until it doesn't bind anymore. Before I do that, is there an easier way to correct this in the sewing machine repair world that I'm not aware of, or is that normally when people just buy a new hook?

[AlZilla]

3 hours ago, brongle said:

. Before I do that, is there an easier way to correct this in the sewing machine repair world that I'm not aware of, or is that normally when

Maybe Sewing Machine Oil? Not to be a smart ass, but just be sure you've lubricated it properly. 

Sometimes it's the simple things that bite us.

[Constabulary]

are you sure that the problem is the hook? Are you sure its not the feed dog that is probably touching the throat plate and it feels like binding? Also keep in mind that you have not installed the spindle, not sure what this does....

Edited Friday at 05:06 PM by Constabulary

[brongle]

12 hours ago, AlZilla said:

Maybe Sewing Machine Oil? Not to be a smart ass, but just be sure you've lubricated it properly. 

Sometimes it's the simple things that bite us.

It's oiled! I just used some light silicone oil for now, but it's definitely not dry. 

4 hours ago, Constabulary said:

are you sure that the problem is the hook? Are you sure its not the feed dog that is probably touching the throat plate and it feels like binding? Also keep in mind that you have not installed the spindle, not sure what this does....

The hook assembly is entirely out of the machine, so I'm not really sure what else it could be... I shot a brief video going over the issues, which might be a little more helpful.

 

I suppose I could throw some lapping compound in there and spin it with a drill... 

[friquant]

Does the hook gib come completely off? Is the bind independent of the the position you hold the hook gib?

Does it also bind when the hook gib is fully attached with screws? (I'm watching with no sound so I may have missed some video details.)

My Singer 96-87 bobbin case, hook race, and hook gib puzzled me during reassembly. Half the time I'd put them together, and the bobbin case would bind pretty strong. The remaining times it would go together and only bind until I got all the screws tightened, then it would run free. It didn't make sense to me. After a couple tries it was running free, so I left it.

The 96-87 does have a lip on the inside edge of the hook gib that was finicky to get it to drop into the hook race, so perhaps that was the issue I was having. 

I usually assume that parts are not deformed, since my own attempts to deform them result in fracture. 🙃

The good news is, it will get better with time. I've heard lapping compound sticks around (embeds in the metal) but I don't have any experience to back that up. Even running it just well-oiled at 500 rpm or higher for a few minutes may loosen it up / wear it into place. When it no longer gets warm when you run it you're most of the way there. 😃 (As long as it's not stressing the bevel gears too much this is what I would consider.)

[friquant]

On 3/5/2026 at 11:43 PM, brongle said:

Made some progress on the timing belt today:

Printed this today in Priline shore 98A TPU. I'm expecting this to work, given that a cloth belt with staples as teeth also works, but if it gives me issues, I can remove some of the clearance in there on a revised print to tighten up the engagement. 

That is cool! I was wondering how you were going to arrange the belt on the print bed. My print bed is only 180mm x 180mm. Is yours big enough to orient the belt in a circle pattern? I don't see any serpentine waves in it (my other thought for fitting large belts on small print beds.)

I suspect / hope your print works well for you. As long as it runs quiet, provides reliable hook timing, and is smooth and easy to turn when mounted in the machine, I think those are the only boxes to check.

Another approach that I have not used but I think is genius is to cut a longer belt down at an angle and superglue the seam: https://leatherworker.net/forum/topic/59855-singer-307g2-problem/page/2/#findComment-645791