29K70/71 - Making my own parts

[mikesc]

If you are going to do much steel..look at CO2 lasers ( a 40Watt unit will start at around $350.00 USD..check Aliexpress ) ..or at least 7.5 Watt and upwards in diode..15 Watt would be better.

[Evo160K]

On 2/8/2020 at 9:23 AM, mikesc said:

There was someone posted here once ( he did not hang around ) that he had a full set of taps and dies for all Singers..even the old ones..But he never demonstrated that it was so, despite much interest from members..A set of those would be more valuable/ useful to some of us than unobtanium.

 

If you're needing those special Singer taps, you can try Keystone Sewing Machine Co., Philadelphia, Pa, (215) 922-6900.  I bought the four tap sizes that LW member Shoepatcher suggested, they've taken care of my needs.  They didn't have dies at that time.

 

 

Snakeoil, I sure like your work!

[Snakeoil]

Nice set of taps. I would expect specialty taps like this to be available thru any of the major tap and die makers. But they probably would not make just one for you. You'd have to wait until they made a run of a particular size to buy just one or two.

The markings on the package just confirmed one of my suspicions. I measured the check lever spring screw thread the other day to make the stud and knurled adjusting nut and it was a tad bigger than an #8 screw. It measured 0.140" OD and a #8 is more like 0.136" OD. I would not expect a screw to be oversize. That's when I looked up at my decimal chart and saw that 0.140" is 9/64. So, I suspected that Singer used their own screw sizes as well as pitches and what I just measured was a 9/64"-40 screw. And now I look at your package of taps and there it sits. Now I understand why the test thread I made for the side thread tensioner stud was too small. I think I made that an 8-40. Will revisit that one soon.

Thanks for sharing your tap set.

regards,

Rob

[Snakeoil]

Finished the Check lever spring adjuster and stud.

Here is the spring adjustor and the Check Lever Thread Take-up Adjuster installed on the machine.

regards,

Rob

[Snakeoil]

Thought I'd share my light mount. I thought about mounting a tubular light in the OEM position. But then I remembered that Walmart sells these great LED desk lamps for about $6. I have one on my bench grinder. So I picked up another one and found a place to mount it on the machine. The base has a 1/2" hole drilled into it. It appears all the 29K machines have this hole. Suspect it is for accessing a bolt or screw under the base.

First job was removing the base from the lamp. Pretty easy. Also uncrimped the cheap, Made in China by prisoners, crimped connectors to disconnect the lead and switch from the lamp. I did not use the switch. The light simply comes on when I plug in the lead. I don't leave it plugged in when not in use.

Using a piece of  threaded lamp tubing , a few nuts, and a small right angle bracket I had in my odd metal box from a previous Go-Pro mount project, I mounted the light to that existing hole. I also had the aluminum spacer. But a stack of washers will work as well. Goosneck allows you to point the lamp to light whatever area you are working on, an of course to light up the needle area when sewing.

Here is a close-up of the bracket mount.

Used the original lead from the lamp, simply removed the base and switch. Terminated the lead to the lamp under the base and then taped the wire to the side of the base to avoid it rubbing on the shuttle driving lever and connecting shaft.

[Snakeoil]

Figured out the thread size for the side tensioner. Once again, the Singer education process plays a role. I'd thought it was a #10 screw with a different pitch thread. I estimated it to be a 36 thread. Too small ID to get a pitch gage on the thread. So, I cut a 10-36 test screw on the lathe and too big. Dropped it down to a 8-36 and too small. The 8-36 threaded in loosely, but stripped. I was thinking that somebody stripped the threads in the head and that's why the tensioner was missing.

Then I found that the thread for the Check lever spring tension stud was 9/64-36. Hmmm, if they used a unique size there, they could have used them anywhere. The story is longer, but I'm probably putting you to sleep by now.

I ended up turning a piece of wooden dowel to 11/64" and then forced it to thread into the tapped hole. Bingo. Gave me a nice impression of the thread. Put my pitch gage on it and it turned out to be 40 tpi. So, it looked like it was an 11/64"-40 thread.  I  checked that against the photo Evo160K posted of his Singer tap set and dang if there is not a 11/64"-40 tap in that set. Thanks again for posting that Evo

Turned an 11/64"-40 test screw on the lathe and fit like a glove.

Went thru my Machinery Handbook looking for that thread size. Nope. There are no thread sizes in 64ths listed in any size. This apparently was a Singer proprietary screw, like most of the other screws on the machine.

regards,

Rob

 

[mikesc]

I've often thought, that when it rained in Kilbowie ..( rainy climate ) they made up screw sizes and thread gauges, and shaft and pin diameters, bearing sizes etc..as a sort compendium of puzzles for engineers..

[dikman]

Snakeoil, welcome to the Wonderful World of Singer Screws! It took me a while to figure out that Singer screw threads are unique.

[Constabulary]

Excellent work! Very impressive!

Now you have to "invent" a 29K bell crank lever that never wears out and produces 6mm stitches...

[Snakeoil]

16 hours ago, Constabulary said:

Excellent work! Very impressive!

Now you have to "invent" a 29K bell crank lever that never wears out and produces 6mm stitches...

Thanks for the kind words.

Funny you should mention that. The other day, I took a plain piece of white paper and ran it thru the machine with no thread. It punched a nice row of holes damn near 5 SPI. Yet when I sew anything thicker than a sheet of paper, which is just about anything, best I can do is about 8 SPI. So, I'm wondering if part of the problem is slippage of the foot. I did sharpen the teeth on the foot with a small triangular stone. But then again, I suppose it could be that the paper offered zero resistance to moving and hence made it easier for a worn bell crank to produce 5 SPI.

I think I might pull the head off the machine tomorrow and get a closer look. Peering up into the bell crank area I see it swings on two screws. Play in those would also contribute to loss of stitch length.

I'm sure a redesign could produce a bell crank arrangement that would not wear. But it would require a major redesign to eliminate the rubbing surfaces of the crank and the ring and replace it with an adjustable pivot point similar to how the foot lift is adjusted.

I have a new Husqvarna machine that I bought for my wife and I'm the only one who has ever used it. I'm suddenly curious in how the stitch length is changed. It's under my desk. May just have to take a peak tomorrow. But I don't see me reinventing the 29K machines in the near future. After all, if it ain't broke...

regards,

Rob