Suggestions for slowing down machine

[dikman]

Well, according to my maths (and I was never any good at maths!) you've got a 2:1 reduction, i.e. running at half the speed it was before. Once you can use that big pulley you should notice a big improvement.

[rockthecasbah121]

Two new belts later and the machines speed and power are perfect!

my wife has OK’ed the speed for sewing collars. One last question on a problem she is having. She is used to the machine automatically raising the needle to the position to remove the item and release the bobbin thread. I know there is an attachment to do this on Juki’s. Can I use this attachment with the pulley adjustment or can I adjust the timing so that it releases the bobbin thread at the highest point of the needle?

[brmax]

It may be two different task your decribing that can be done. I believe the first she could be refering to is the “ needle positioning “ this is a electronic motor setting, be it servo motor or older clutch type with great electronics. 

The second is an attachment your mentioning; there is the presser foot that can raise with your knee on a cushioned lever and or by hand near the needle, with another lever.

The electronic needle positioning may only work correctly with the reducer if a reduction ratio is limited to 3 to 1, this has been talked about in post somewhat. So it may not work. 

 

Good day

Floyd

[dikman]

As Floyd said, you're referring to a needle positioning system. Servo motors often have it as an option, a sensing device that can be attached to the side of the handwheel. The motor can be set so that the needle stops down or up when you take your foot off the pedal. When I fitted a speed reducer my NPS wouldn't work due to the electronics not coping with the changed ratios caused by the extra pulleys in the drive train. Didn't bother me though as I found it a nuisance and unnecessary for slow speed sewing in leather.

[Davidmadd]

Just out of interest I've just posted a reply to someone who has just set up a speed reducer.  In case you cant find that reply I mentioned that due to my complete lack of sewing skills I wanted a really slow and easily controlled machine and have used a 250W DC motor.  It needs a 24V DC power supply and a 24V DC Motor speed controller.  A potentiometer then easily controls the speed from 0 to max revs.  I found a spring loaded arm potentiometer and connected a presser foot lift pedal to it.  It works great on my 31K15 and 31K47 but my 111W154 needed a larger sewing machine handwheel and pulley for best result.  I can now do single stitches, start, stop or put my foot down and get a decent speed when needed.  The motor, power supply, controller and foot pedal are far less bulky and industrial looking than the standard clutch motor and this has worked for me.  I have now acquired  larger slightly equipment and will soon by driving my 132K6 and 45K by DC power.

Hope this helps, Regards  David - Plymouth, UK