Connect with us

Very slow sewing machine motor operation.

Discussion in 'Sensors and Actuators' started by mikeincousa, Sep 5, 2016.

Scroll to continue with content
  1. mikeincousa

    mikeincousa

    13
    0
    Sep 5, 2016
    I am brand new to this forum. I am a very rusty electronic experimenter.

    Needing to slow down a sewing machine for better control I built a little jig.

    The jig limits the travel of the foot peddle to a point where I need to turn the hand-wheel to get it started.

    From there it does not sound like the motor is straining and it produces solid stitches.

    My first question.

    Will prolonged operation at this level hurt the motor in the long run?
     
  2. KJ6EAD

    KJ6EAD

    1,114
    158
    Aug 13, 2011
    Only if you stall it a lot. The bigger problem will be the excessive heating in the resistive pedal which will probably lead to the element failing. The obviously most desirable solution would be a different drive ratio but that's complicated by the fact that the motor pulley is usually quite small already and the machine pulley has a built-in clutch. Possibly, you could mount a dual pulley idler between the motor and machine to adjust the ratio.
     
  3. mikeincousa

    mikeincousa

    13
    0
    Sep 5, 2016
    KJ6EAD. de KA9TTY.
    This is an inexpensive home sewing machine. I have not had any reason to look a the drive mechanism. Would the modification you suggest be possible? Could you point me to a drawing?
     
  4. Bluejets

    Bluejets

    4,414
    935
    Oct 5, 2014
    Like so........
     

    Attached Files:

    CDRIVE, hevans1944 and KJ6EAD like this.
  5. Rapidrob

    Rapidrob

    11
    6
    Sep 12, 2016
    For what it is worth, Harbor Freight sells a motor speed controller that is dial controlled. It slows the motor down but keeps the current up to allow the motor to not overheat. I think it is rated for 15 amps?.
    It has a 115 VAC receptacle built into it. You plug in the sewing machine,"floor the foot pedal" set the speed knob, and use it as you'd normally would but it is running slower as you need it.
    I use it on an 1/8 HP high speed precision drill press and it works very well. It's under 20 bucks on sale/coupon.
     
    KJ6EAD likes this.
  6. Bluejets

    Bluejets

    4,414
    935
    Oct 5, 2014
    Standard triac phase angle controller....nothing special.
    Heating of the motor at low speeds will still apply.
    As for keeping the current up...water is an analogy for electricity.i.e. more current does not assist cooling.
     
  7. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

    4,960
    651
    May 8, 2012
    Do you need to preserve the max RPM of the motor? If not you may be able to replace the motor with a Gear Motor. You will loose the top sewing speed you now have but gain very good slow speed operation with plenty of torque.

    Chris
     
  8. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

    4,960
    651
    May 8, 2012
    Yup, the intermediate (pulley + shaft + bearings) assembly is called a "Jack Shaft".

    Chris
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-