The Upholstery Forum

What adjustments or tweaks if any can one do to improve low speed control on a clutch motor? I had a Singer 78-1 that had great speed control with a clutch motor. Just got a 132K6 and it's either engaged at full speed or nothing

A longer throw for the rod from the treadle to the clutch and or a different pulley will help but...... servo motors are relatively cheap, easy to install and just work awesome. You won’t be sorry.

There is a bolt near the clutch motor lever that will adjust the clutch engagement. Back it off a couple turns and see if that helps. As @Revv Up stated, get a 1.5-2" pulley (45-50mm) and maybe stuff some foam under the pedal. Put some vaseline or grease on the clutch cork to help it slip. Back off of the belt tension too. If all that doesn't tame it enough...get a servo.

I made the linkage adjustment and cleaned the metal clutch disc as it had some burnt cork on it and sanded the cork on the motor side. It's somewhat better but still hangs up a bit at start and lurches forward. I can see it always hangs up right as the needle foot is lifting. If I nudge it over that point by the handwheel it's possible to get going at a low speed but not super consistent.

I thought about putting graphite on the cork as it would be reversible by sanding it off but so far decided not to.

Is it common to grease the cork? I know a motorcycle clutch has cork plates and they run just fine bathed with oil.

I know I could get servo, I have them on two other machines and they are fantastic. In this case I'm trying to get it functional enough to use it for a few projects to see if I like it while spending as little as possible doing it. It's my first machine with a rotary hook and it's a monster of a machine (Singer 132K6). If I like it will replace my Consew 28-1 if I don't it'll go back up for sale.

After writing that it probably makes sense to temporarily move a servo over to it for a test.

There you go, swap it with a servo for now and stick the clutch motor on whichever one you sell. Cork gets old and dried out, not sure how common it is to grease them but it does work.

If I keep it I will get a servo. But for for now I'm making a pulley set to slow it down. The kind that's on a jack shaft between the motor and the machine. It will take me down in top speed by a factor of 2.6. So instead of a top speed of 730 stitches per minute I'll be more like 240 stitches per minute max. It should give me more torque to overcome the friction at the start of sewing more smoothly too.

I figure the effort of making the pulley set is worth even with a servo drive as it will let me use more of the speed range of the servo. Low speed with the servo will be like 30 stitches per minute and top speed will still be about 630 stitches per minute.

Progress so far. I need to enlarge the slot a bit and make a spacer for the pulley on the motor to account for the offset made by the step down pulley.

With temporary belts. I just had to check it out for speed. The middle of the video is top speed for now. Top speed is about 240 stitches per minute with a 1725 rpm motor.



Video link

Today's progress. Bobbin winder mounted and everything bolted down.

Dang bro! Thats pretty slick, nicely done.

That is a really cool setup you made!!

Thanks for the comments!

Here's the latest. I added the tension unit for winding bobbins and nudged things a bit so I can tip the machine for oiling without have to move anything. I did not like the bobbin winder right near the hand wheel, the extra clearance around the hand wheel is really nice as the control via the clutch motor is still not perfect.

Im very impressed!

You are very tallented, that pulley that you have engineered is just amazing, good skills there. Could you?, would you be prepared to make some?; I'm sure that you could sell them; I for one would be a buyer. I have an old singer 31k15, which I absolutely love, I am currently running it on a modern servo motor, but for various reasons want to go back to a clutch motor, but If I had a pulley, like the one that you so skillfully made, I would find things much easier.
My Regards.
Stephen

May I please ask... Why on earth would you want to go back to a clutch motor from a servo? What are the "various reasons"? I admit that I'm a relative newcomer to industrial machines but all I know is that folks should replace clutch motors with servos.

Nice work ya did there. 240 is a good slow speed for me lots of times.

@Mtl_Biker Old school clutch motors typically have more power than modern servo motors. That can be important if your sewing a lot of heavy duty things like very thick leather. The extra power isn't really important for auto / marine upholstery in my opinion.

Mtl_Biker wrote: ↑Fri Apr 01, 2022 3:08 pm May I please ask... Why on earth would you want to go back to a clutch motor from a servo? What are the "various reasons"? I admit that I'm a relative newcomer to industrial machines but all I know is that folks should replace clutch motors with servos.

If you watch any of Cechaflo’s YouTube videos you can see his ability to stop the machine just before the needle pierces the fabric (he uses mainly leather) allowing him to do some extremely fine work, I doubt you can do this with a servo unless you drastically changed the needle position settings, the clutched motor would have more grunt to push the needle through thick fabrics from this position if this was the intent.

I really like my servo motors

If the machine is new to you, then more than likely it sat for a while unused, and develop a light coat of rust. If you break it in against restoring the glazing the control should dramatically improve.