Improving control of clutch motor

[RWL2]

Before and after photos of the modification I made to the foot control for the clutch motor on my sewing machine.  By extending the control bar of the clutch you have to move the foot pedal more to get the same effect.  It is slightly easier to come to the end of a seam and stop where I want to.  The suggestion came from another member of the forum a couple of months ago.

[Pintodeluxe]

I tried this mod, but felt like it was a waste of time.  For me, I settled on a servo and a box style speed reducer.  I probably could have got away with just a servo.  

The only thing I've found that truly makes a clutch motor easier to control is to add grease to the friction plate.  Especially if it was previously dried out, greasing the cork friction plate helps you slip the clutch.  

Is your clutch mounted to a reducer?  Or some other reason it sits so low?  

[RWL2]

1 hour ago, Pintodeluxe said:

The only thing I've found that truly makes a clutch motor easier to control is to add grease to the friction plate.  Especially if it was previously dried out, greasing the cork friction plate helps you slip the clutch.  

Is your clutch mounted to a reducer?  Or some other reason it sits so low?  

Yes, the speed reducer lowers the clutch motor by about 9" if I'm remembering the dimension correctly.

Was there any downside to greasing the cork friction plate?  Did it slip when sewing through tough material after being greased?  How greasy did you make it?  Is it worth greasing the brake to make it easier to turn the handwheel?

[dikman]

6 hours ago, Pintodeluxe said:

I tried this mod, but felt like it was a waste of time.  For me, I settled on a servo and a box style speed reducer.  I probably could have got away with just a servo. 

Same here. I spent a lot of time experimenting with extending the clutch arm, made a small speed reducer, fitted a larger pulley to the handwheel and in the end fitted a servo and reducer.

[keithski122]

I've also done this but on a servo motor machine.I've extended both the pedal arm and the controller arm, possibly only by a few inches on each but every little helps.

[sandmanred]

I have greased the clutch side but not the brake side.  I have a Singer 132K6 with a 3:1 speed reducing set up between the motor and machine.  I've not experienced any issues with the clutch slipping under load, one of my belts always slips first.  The grease helps but it's still not a servo 

[RWL2]

I didn't do a search here at leatherworker to check, but I wonder if anyone has used an old treadmill motor and controller as a poor man's servo.

[Kcstott]

6 hours ago, RWL2 said:

I didn't do a search here at leatherworker to check, but I wonder if anyone has used an old treadmill motor and controller as a poor man's servo.

If I had the motor and controller and no money I'd figure it out and make it work. 
but with the price of servo motors that are near drop in units? Leather machine co has them and so does Springfield leather. 
LMC wants $175
SLC wants $160 
Reducers run about the same cost so for a little over $300 you could have this taken care of. 

[DonInReno]

On 11/27/2020 at 2:49 PM, RWL2 said:

I didn't do a search here at leatherworker to check, but I wonder if anyone has used an old treadmill motor and controller as a poor man's servo.

Once upon a time I read a post somewhere else where a guy used a treadmill motor and a reducer with a 132k6 with what he thought was good results.   Momentum in the treadmill motor keeps spinning a bit after power is cut, so that must affect how you sew a bit, and these are not known for great torque in the low rpm range so a reducer still makes sense.  Technically, a speed controller with braking function can be used, but that alone is as much as a complete sewing servo setup.

Having said that, ever since reading that article I’ve wanted to try a treadmill motor just to see how good or bad it would be.

[RWL2]

The momentum in the motor would be a real negative.  It's something I hadn't considered, not that I have a spare treadmill motor lying around.  It's not just going slow that matters.  It's the ability to stop with the needle up or down near the end of a seam.  I've at least got some control of that now with the speed reducer and extension of the clutch arm.

 

[dikman]

Many have used treadmill motors to drive small lathes and they appear to work well but Don makes a good point about why it might be problematical on a sewing machine. Given that servos are relatively inexpensive and are a simple plug-and-play it seems like the logical way to go.

[Pintodeluxe]

On 11/25/2020 at 5:29 PM, RWL2 said:

 

Was there any downside to greasing the cork friction plate?  Did it slip when sewing through tough material after being greased?  How greasy did you make it?  Is it worth greasing the brake to make it easier to turn the handwheel?

About a teaspoon of grease on the friction plate.  It just makes it slip a little smoother, but didn't cause unwanted slipping.  I've never tried grease on the brake.  

[RWL2]

Thanks Pintodeluxe.  I haven't looked carefully yet at how the clutch is removed from the end of the motor.  I suspect it won't be hard to remove since they were intended to be used in production facilities where time is money, but I've never taken one apart before.

[Constabulary]

You most of the time have clutch motors with approx 1400 /1500 rpm or 2400 / 2800 rpm.

How many RPM has your motor if more than 1500 I would replace it no matter what.

Edited November 30, 2020 by Constabulary

[RWL2]

1750 RPM Singe phase. Speed reducer with 2" to 8" pulley and the drive pulley to handwheel pulley is about 2" to 3".  I didn't put my tachometer on it recently to see what the speed of the machine is, but It was somewhere around 400 RPM.  The maximum speed isn't a problem.  It's getting the slow speed when coming to the end of a seam when you want to place the needle just so.

  I may eventually get a servo motor, but it's not in the immediate future.

[Constabulary]

okay so a 2" to 8" pulley reduction can do the trick then. But I would  replace it with a servo.

[RWL2]

I greased the cork clutch pad today.  I wish they'd build these things with fasters with a hex head rather than a phillips head.  I got the three retaining screws out, but they were tight and I worried about stripping the heads.  Photos of the clutch for anyone who's never seen the insides.  The first shows two of the three screws that holds the clutch on.  The second shows a thin layer of rust on the steel clutch plate.  The third is a closeup of the cork clutch pad and the fourth photo shows the greased pad next to the SuperLube that I used.

 

[DonInReno]

That rust will give you fits - hopefully it sanded off easily.

[RWL2]

12 hours ago, DonInReno said:

That rust will give you fits - hopefully it sanded off easily.

It was just surface rust.  I hit it with a little steel wool and it came right off.  I think the previous owner had the table in her garage.  Now it's in my cellar which is relatively climate controlled and dry.

[sandmanred]

Did it work?

[RWL2]

1 hour ago, sandmanred said:

Did it work?

I'm assuming you mean the greasing of the cork rather than whether the steel wool took off the rust.  The grease made a minimal difference.  There's no discernable slack between the clutch beginning to engage and the brake holding back the machine.  I think a bigger gap there would help but I haven't explored how to make those settings wider.

[Wizcrafts]

1 hour ago, RWL2 said:

There's no discernable slack between the clutch beginning to engage and the brake holding back the machine.  I think a bigger gap there would help but I haven't explored how to make those settings wider.

You adjust the slack by turning the big hex head bolt on the pulley end in or out. In reduces the slack and out increases the free motion. My guess is yours is already all the way in.

[RWL2]

I don't know if it was all the way in or not when I started since I began by backing it out.  ....and kept going till the brake shoe fell off the bolt.  Doh!!  I had difficulty detecting much difference except at the two extremes.  When too loose the machine would coast a stitch or two beyond where I wanted it to stop.  Too tight and I had trouble being able to feather the clutch, plus the clutch lever started to move down toward engagement with each turn of the bolt.  I backed it out until I could control it again and then backed it out slightly more.  A servo no doubt is the way to go.  I just don't want to spend the money at this point.