7-34 Motor recommendation ?

[mikesc]

Greg, could one not use a solenoid ( electric ) foot lifter ? I have an EFKA speed controller NPS on a Juki DLU 490-4 , the machine also has a separate solenoid mounted under the table to activate the foot lift ("heel back" on the foot pedal activated for the foot lift solenoid ) and a small "paddle control" just to the right of the needle to activate reverse as well as the usual second smaller pedal ( next to the speed pedal ) reverse system ..( There's load of stuff in the way or I'd take a photo ) ..Makes a definite "click" when the solenoid fires for up or down, but less noisy than having a compressor running for air controls..

It is an old EFKA unit ( looking for information about it and the machine was what brought me to leatherworker.net..Eric kindly pointed me towards the mechanic's manual for the machine, as you know top and bottom differential feed ..He figured that from my description of the noise from the EFKA that it is tired :) ..but as I only use it occasionally I am in no hurry to change it..As you say, EFKAs can be dialled down to run very slow, I added "bump stops" under the speed pedal to limit the top speed by limiting the pedal "travel", and a child's inflatable ball to give air resistance under the same pedal to allow a more progressive throttle..

It isn't quite as slow as running a servo with a reducer ( like my Singer 211 set up ) but is easily controllable..although EFKAs are more expensive, I see many more people in Europe using them on the older machines..

I know that Tor swears by Efkas, and he runs some heavy machines..could well be a good controllable set up for the 7-34.

Edited May 23, 2019 by mikesc

[Gregg From Keystone Sewing]

2 hours ago, mikesc said:

Greg, could one not use a solenoid ( electric ) foot lifter ? I have an EFKA speed controller NPS on a Juki DLU 490-4 , the machine also has a separate solenoid mounted under the table to activate the foot lift ("heel back" on the foot pedal activated for the foot lift solenoid ) and a small "paddle control" just to the right of the needle to activate reverse as well as the usual second smaller pedal ( next to the speed pedal ) reverse system ..( There's load of stuff in the way or I'd take a photo ) ..Makes a definite "click" when the solenoid fires for up or down, but less noisy than having a compressor running for air controls..

It is an old EFKA unit ( looking for information about it and the machine was what brought me to leatherworker.net..Eric kindly pointed me towards the mechanic's manual for the machine, as you know top and bottom differential feed ..He figured that from my description of the noise from the EFKA that it is tired ..but as I only use it occasionally I am in no hurry to change it..As you say, EFKAs can be dialled down to run very slow, I added "bump stops" under the speed pedal to limit the top speed by limiting the pedal "travel", and a child's inflatable ball to give air resistance under the same pedal to allow a more progressive throttle..

It isn't quite as slow as running a servo with a reducer ( like my Singer 211 set up ) but is easily controllable..although EFKAs are more expensive, I see many more people in Europe using them on the older machines..

I know that Tor swears by Efkas, and he runs some heavy machines..could well be a good controllable set up for the 7-34.

Singer 7-31, -33 and -34 do not have a foot pedal operated foot lift, only the hand lever.  We have put some cylinders for presser foot lift, but it's not pretty but has worked.  Electronic solenoids work well, up to a point.  See link for video of  24V solenoid with SP-1100 motor

These solenoids can be of course used with the Efka motor's 24V output for foot lifting.

As for speed control, I make up these speed control dials mounted external from the control box.  I can set the machine from say 50rpm up to maximum 800 and everything in between to limit the upper limit of maximum speed of the motor.  Speed control example video

Edited May 23, 2019 by Gregg From Keystone Sewing
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