Singer 29K70 questions

[Snakeoil]

Did some more investigating, inspection and correction on the machine. First, the tension discs were a mix or one top and one side disc. Had spare top discs and fixed that. The leather washer that belongs under the bottom disc was also missing. Made one.

Drove the pin out of the piston and removed it and the check lever. Number on the piston 2231, indicates that it is from a 29K71. The correct piston for my machine is a 81860. The check lever is correct for my machine. The driving lever for both the 70 and 71 machines are the same 82220 (typo on 29K70 parts diagram. Shows it as 8222C, but parts list shows 82220). I tried to find the number on the driving lever, but suspect it is on one of the non-painted surfaces, probably where the Joint Pin goes so I'm going to assume for now it is correct for my machine. The threaded area for the check lever tension stud is counterbored, which indicates to me it was intended for a stud and not a screw since the spring covers the counterbore.

My options are to get a new piston assembly for my machine or the missing parts for the piston I have. I could make them, but the diagram detail is bad.  So,  I know how many parts there are and can guess based upon how I think it should work how each is configured. But would be just that, an somewhat educated guess.

I'll try the parts outfits for those part numbers to see if they have them, or at least photos of them.

regards,

 Rob

[Snakeoil]

Well, it turns out that a good chunk of the answer to my question was in a later issue of a 29K operation manual that came with the machine. It is so soaked with oil that the pages are all translucent. I actually was looking at it because I was looking for thread size limitations. Back page had a great diagram showing the adjuster on the end of the piston. Armed with that I was able to watch the lever move and can see what the parts need to look like to allow adjustment of the lever travel. I can also see how the adjustment can alter the tightness of the stitch as well as the centering of the lock. I'll post pictures of the part when I get around to making them.

The tensioner on the side of the machine for darning was missing. I did find one of the discs installed in the top tensioner as mentioned before. I cannot get a thread gauge into the tapped hole in the machine head to measure the pitch. But comparing it visually with my thread gauges, I came to the conclusion it is either and 8-36 or 10-36 thread. Well, it appears it was an 8-36 and some ham fisted rebuilder or previous owner stripped the thread in the head. I machined a 10-36 thread and it would not fit. The 8-36 fit and then stripped with minor finger pressure twisting the screw. So, I'll probably just tap it for 10-32 and make a new stud for the tensioner that fits.

I did some practice sewing to check my stitch quality and pitch. Set at 5 SPI, I get about an 8 to 8.5 SPI. I feel play in the bell crank so I need to replace it or repair it. It's not obvious how the internals come out of the sewing head. I see a couple of screws that probably hold everything in place. But I need to study it a bit before taking it apart and watching it barf the internals all over the floor. Actually, I'm a white towel guy and that will get laid on the table before anything is removed. If anyone know of a tutorial on how the head comes apart, that would be helpful. I'm going to search the web for info. I may just weld up the worn area of the bell crank and reshape it to restore the max thread pitch capability.

I did figure out a way to revive the treadle to see if I liked it. I had miles of oxygen tubing left over from my Mom who died of cancer 30 years ago. It's quarter inch clear plastic tubing. It is not too stretchy and figured it would do for a test run. Fit a piece to my machine, which requires 7'-6" of belt due to the tower extension, and used a piece of plastic covered cable (from the dog's run) as a coupler. Works the nuts. Really prefer the treadle over the wimpy electric motor. Speed is perfect for a newbie like me and the control is excellent. So, if anyone needs a new treadle belt for a 29K machine, go to your local hardware store and buy some 1/4 plastic tubing (19 cents/foot locally) and make yourself a new belt. Bet it will last a lifetime.