Will The $150 Chinese Servo Motors From Ebay Work On An Old Adler 68?

[Northmount]

Yup, thinner thread in the same size needle makes it easier to pull the knot up, so would as you found require a decrease in top tension.

Lots of playing and practice will go a long ways toward "making the machine" behave. Overcomes the operator error problem.

Tom

[dikman]

Welcome to the wonderful world of industrial sewing machines! I too soon learned that if I didn't hold onto the two threads it created a wonderful mess!

[Vinculus]

Thought I'd give you guys an update on this.

I received my Jack JK-513A servo motor from College Sewing today and installed it - and everything works, so thanks for all the help! It still sews a little fast at the lowest speed setting, so I will be getting a 40 mm. pulley for the motor. Probably won't bother with a speed reducer since it seems like a lot of work that I don't know how to do.

Do any of you know what kind of bore the JK-513A pulley uses? I don't feel like removing the original one just to find out and put it all back together again

[dikman]

To the best of my knowledge they are all the same size. If it is listed for a sewing machine it should be the correct size (my local industrial sewing machine shop told me this). I've ordered several different diameter pulleys from China (ebay) and they are all the same shaft diameter.

[Kohlrausch]

To the best of my knowledge they are all the same size. If it is listed for a sewing machine it should be the correct size (my local industrial sewing machine shop told me this). I've ordered several different diameter pulleys from China (ebay) and they are all the same shaft diameter.

Oh, I thoght there were all kinds of diameters like 8,5 mm, 9,3 mm, 10 mm, several tapered bores, all kinds of inch fractions. You probably got lucky.

When I asked Colege Sewing about exchange pulleys they said, there were none. I should change the speed settings.

Greets

Ralf C.

[Vinculus]

Oh, I thoght there were all kinds of diameters like 8,5 mm, 9,3 mm, 10 mm, several tapered bores, all kinds of inch fractions. You probably got lucky.

When I asked Colege Sewing about exchange pulleys they said, there were none. I should change the speed settings.

Greets

Ralf C.

College Sewing told me the same, and even added that the stock pulley is "fixed". This is obviously not true, since it's fastened with a regular nut and washer.

Anyway, after searching this forum, I found that the Jack motors have a 13 mm. straight bore shaft. This is some kind of stupid non-standard size, so it looks like I'll have to have 40 mm. pulley custom made.

I am wondering, however, if a 15 mm. straight bore could work. The pulley has a notch and the shaft should have the key for this notch, so it's not like a 15 mm. bore pulley will spin around freely. What do you guys think? The pulley might rotate 2 mm. off-center, but otherwise it should work, no?

I'll probably have a 40 mm. pulley custom made anyway. At 200 rpm, which is the crawling speed of the motor, it's still too fast for the delicate and non-linear work shoes require. Should probably think about building a speed reducer as well.

[dikman]

My first thought was "they don't know what they're talking about!" Unless they had that motor specifically made for them (unlikely, as it's similar to several other brands for sale on AliExpress) then the shaft will be 15 mm. I also have two generic clutch motors, both a few years old, and both have 15 mm shafts. Like I said, the guy at the shop (who has been in business a long time) said that 15 mm is pretty much a standard shaft size for industrial-type sewing machine motors.

Don't take their word for it, remove the pulley and measure the shaft, that way we'll both know.

[Vinculus]

Well, it wasn't easy, but I got the stock pulley off. It does indeed appear to be some kind of non-standard size and configuration. The shaft is 13 mm, bummer.

What is really weird is how the key for the pulley bore is a separate piece of metal that was just jammed in there. I was under the assumption it would be part of the actual shaft. Is this normal? See attached pictures.

Looks like I'll have to get a custom pulley made. Sucks!

[Kohlrausch]

In Germany I find 12 mm and 14 mm bores, no 13 mm. I'ld try a 12 mm and a 13 mm drill. Or a 14 and a little bit of sheet metal to fold around the shaft.

Greets

Ralf C.

I found that the Jack motors have a 13 mm. straight bore shaft.

I am wondering, however, if a 15 mm. straight bore could work. The pulley has a notch and the shaft should have the key for this notch, so it's not like a 15 mm. bore pulley will spin around freely. What do you guys think? The pulley might rotate 2 mm. off-center, but otherwise it should work, no?

[Kohlrausch]

My first thought was "they don't know what they're talking about!" Unless they had that motor specifically made for them (unlikely, as it's similar to several other brands for sale on AliExpress) then the shaft will be 15 mm. I also have two generic clutch motors, both a few years old, and both have 15 mm shafts. Like I said, the guy at the shop (who has been in business a long time) said that 15 mm is pretty much a standard shaft size for industrial-type sewing machine motors.

Don't take their word for it, remove the pulley and measure the shaft, that way we'll both know.

At this very moment I have pulley with three different tapered bores lying around me and motors with three different cylindrical shafts. There certainly are a lot more possibilities than 15 mm. Wish it were that easy...

Greets

Ralf C.