Dakotanorth

The clutch motor....

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I am slowly training up on the Pfaff 345 I recently bought from Chris.  It is a great machine, and it works much like my household machine from the 1950's.

I'm still struggling with the clutch.  I get the classic sequence:

Nothing...nothing...nothing,,, it starts to vibrate....WHAM!! It takes off at 1000spm.  I  have been able to soften this a bit by rolling the wheel by hand, as the motor starts to move the needle, but that sometimes requires 3 hands.

What's the verdict on using pulley systems to reduce the speed?  Are Servo motors big bucks?

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GPaudler   

I put a servo motor on my Pfaff 335 without a speed-reduction and it works great. I've bought three from Alberoni's (in Orange County) eBay store or listing for about $115 with free shipping. Plenty of other merchants, as well. They are designed to mount easily in place of the standard clutch motor. If $115 doesn't hurt, you won't be sorry and you could spend that, or more, monkeying with a speed reducer trying to get your clutch motor to behave.

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dikman   

It might be worth dismantling the clutch and checking the condition of the clutch material and making sure it's smooth and the facing plate is clean and smooth, BUT it takes a bit (a lot?) of practice to learn to control a clutch motor, particularly if you want to go slow for leatherwork. You could fit a smaller pulley to the motor and fit a speed reducing pulley setup, but for a newcomer a servo is probably the way to go, as it will give you control and inspire confidence.

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MADMAX22   

If you stack foam or similar under your pedal it helps to ease into it, wont be the same as a servo without the speed reducer. That being said a servo really needs a speed reducer to go slow because of the loss of torque at slow speeds but its more manageable overall. 

You can replace the pulley on the clutch motor cheaply as it probably has like a 3" pulley (or bigger). 

A clutch motor should have a little bit of a sweet spot that allows you to slowly roll into it. Dikman is right about checking it out some. 

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Alot of times the

cork dries out,we have always told people to smear about a teaspoon of grease on the clutch pad & run the belt as loose as you can!

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Uwe   

Personally, the only clutch motors I like are the ones attached to fancy Efka controllers. Unless you have some nostalgic attachment to plain clutch motors, there's really no need to subject yourself to them. 

Even a $115 cheapo servo motor with a small 2" pulley will make a world of difference. For around $200 you can buy one of my personal favorites, a Sewpro 1,100W servo motor with plenty of low-end torque and very low 100rpm starting speed (most other servo motors start spinning with 300 rpm.)

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On 2/12/2017 at 6:03 PM, Dakotanorth said:

I am slowly training up on the Pfaff 345 I recently bought from Chris.  It is a great machine, and it works much like my household machine from the 1950's.

I'm still struggling with the clutch.  I get the classic sequence:

Nothing...nothing...nothing,,, it starts to vibrate....WHAM!! It takes off at 1000spm.  I  have been able to soften this a bit by rolling the wheel by hand, as the motor starts to move the needle, but that sometimes requires 3 hands.

What's the verdict on using pulley systems to reduce the speed?  Are Servo motors big bucks?

....And that's what we call a jackrabbit start, this occurs when the belt is too tight.  Easy to do on the longer post bed machine drive belts.  If the belt is too tight, it will go from 0 to 60 in no time, with very little in between in terms of a power band.  Try backing off on the motor belt tension, this should help.

Also...if the clutch lining (cork) is worn, or glazed over, this could be an issue, as well.  Taking off the end bell of the motor to expose the cork, you can hit it with some light sandpaper to break off the glaze, and then put a thin layer of axle grease (we use Castrol multipurpose wheel bearing grease here).

These two things may help go a very long way to getting the motor under control.  Again, we like to sell servo motors as replacements, but people have been successfully doing may things on machines like these with standard clutch motors for many many decades without too much issue.

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Thank you everyone.  I appreciate the help and insight!

Slowly I am getting used to the clutch motor.  A trick I learned with my home machine is this:

IF the power is turning the wheel, but it looks like it might "jackrabbit" start, then I start to hand crank the wheel.  Just a touch; just enough to break the tension and move it.  The instant it does I put my hand back onto the work.

I'm also learning to drive it barefoot- I use my toes and curl them over the end of the plate to apply a slight amount of pressure.  Your toes aren't that strong, so it's hard to apply too much force!

 

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I've been barefoot the whole time with mine and despite nearly 20 years of pedal control from TIG welding, I still don't like how binary the inputs are with the clutch motor.  Fortunately, my servo shows up Thursday and I'm getting itchy. :yeah:

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Cascabel   

My personal cure for that problem is to apply a suitable amount of pressure on the hand wheel with my right hand, sort of like a brake to slow things down, if need be.  It helps a lot to have a huge wheel on the machine, and a small pulley on the motor, like what I have on my 42-5.   Very easy to control that way

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Really - get the Servo motor - Clutch motors also use HUGE amounts of electricity to stay spinning, the Servo motor is nice and silent and uses a lot less electricity. 

You will not regret it. 

 

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3 hours ago, Yetibelle said:

Really - get the Servo motor - Clutch motors also use HUGE amounts of electricity to stay spinning, the Servo motor is nice and silent and uses a lot less electricity. 

You will not regret it. 

 

Actually, an AC motor that has no load on it uses very little electricity to remain spinning.

That said; the buzzing noise, table vibrations, jackrabbit starts, massive power dump into the machine at the onset of a stitch - are more than reason enough to remove the bloody thing and put a servo on it.

I was fighting my clutch motor again last night trying to resolve a tension spring issue (top tension bracket wasn't fitting quite right causing the thread to stick behind it) and was seriously questioning my Singer 211G purchase vs a 441 clone and wondering how I was going to come up with the money to upgrade if the servo didn't do the trick.  Well, my servo's been on for a couple hours and I'm already completing work that looks better than the last guy I paid.

Get the servo!

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ndnchf   
On ‎2‎/‎13‎/‎2017 at 1:13 AM, Uwe said:

Personally, the only clutch motors I like are the ones attached to fancy Efka controllers. Unless you have some nostalgic attachment to plain clutch motors, there's really no need to subject yourself to them. 

Even a $115 cheapo servo motor with a small 2" pulley will make a world of difference. For around $200 you can buy one of my personal favorites, a Sewpro 1,100W servo motor with plenty of low-end torque and very low 100rpm starting speed (most other servo motors start spinning with 300 rpm.)

Can you share a link to this Sewpro 1100 servo motor?  Google search is not finding it. I don't see it on the SewproUSA site either. Thanks.

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Uwe   

Sewpro does not have the SP-1100 motor (or SP-1100 NPFL with needle position and foot list) on their website yet, I'm not sure why. They had brought the motor to the TexProcess trade show in Atlanta last May, which is where I first met Sergey (Mr. SewProUSA) and we talked about the motor at length. Excellence in sewing technology and webmastering don't always go hand-in-hand. You basically have to call and inquire about the motor, something rather common in the sewing machine world.

One key feature I like about this motor system, aside from the power and low speed torque, is actually the control interface. You can control the needle position function with a simple button that cycles through Up/Down/Off states, which is how it should be. Motor top speed is adjusted via simple "+" or "-" buttons, which is also how it should be. Other, more esoteric functions are set via a crude menu system that is just as cryptic as other controllers.

The needle position sensor is optional and runs about $25, I think. I'm not connected to SewPro in any way other than having talked to Sergey and ordered two of his SP-1100 motors. I just like the motor, that's all. 

I took a few pictures of my  SP-1100 NPFL motor, which is currently serving mobile test setup duty. The motor body itself measures about 4" square on the mounting faceplate and 6" long (not counting the pulley).

IMG_7441.jpgIMG_7442.jpgIMG_7443.jpgIMG_7444.jpgIMG_7445.jpg

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ndnchf   

Thanks for the photos and explanation Uwe. No wonder I couldn't find it. I've got a Singer 31-15 clutch motor machine I've been thinking about upgrading. I like the low speed torque feature, I'm not in any hurry with my projects. 

Steve

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TZHunter   

Steve, I've got a 31-15 that I too was seriously thinking about getting one of these servo motors for. Let me know how it works out for you.

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Must have that motor..............Any idea when they will be available for sale?

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SARK9   

I was looking at the decal where it says "Foot lift output 24V" and thinking hmmm....

 

-DC

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