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servo motor or speed reducer pully?

14K views 5 replies 3 participants last post by  DanTwoLakes 
#1 ·
I have a Consew 255 RB2 that is way faster than I am. Even after changing the 3400 rpm clutch motor to 1750 rpm unit it is still too fast. I believe that my options are a servo motor or a speed reducer pulley setup. I would really appreciate some feedback on these. I have heard that servo motors lack power a low speed and are noisy but I don't know anyone that has used the speed reducer. I want to use this machine to do the interior for my 29' Dodge sedan and I need accuracy not speed. Thanks guys.
 
#2 · (Edited)
O.K., A 1 HP electric motor running at 1750 RPMs produces 3 Ft. Lbs. of torque. So....a 1/2 HP motor ( which is what most industrial sewing machine motors are) running at 1750 RPMs produces 1.5 Ft. Lbs of torque. A clutch motor is either on or off, just like the clutch in a car. An experienced sewer, or an experienced driver, can make a car, or in this case a clutch motor, slip through the foot pedal (or clutch pedal) to make it a variable speed device, but this takes a lot of experience and it is still either on or off. The slower you go the more torque you can produce. Servo motors are constant torque devices, so at any speed, a 1/2 HP motor will produce 1.5 ft. lbs. of torque. A clutch motor running full speed will produce the same amount of rated HP and thus the same amount of torque, and perform exactly the same as a servo motor. But: clutch motors on sewing machines rarely, if ever, are run at full speed, so they are more powerful at slower motor speeds than servo motors.
What does this mean to a sewing machine operator? Although my sewing machines have less power than a traditional clutch motor at slower speeds, the accuracy and control I have over the machines more than outweighs any loss in power. I have been sewing for almost 35years, and I have yet to find a situation that the servos won't handle. I wholeheartedly recommend changing clutch motors to servo motors. If you can't afford to change to a servo motor, put an extremely smaller pulley on the clutch motor to slow the machine down. If you put a pulley on the clutch motor half the size of what came on the motor, the speed will be cut in half.

I sew every day for a living, and have a Consew 255 RB-3 and a Consew 226- R that I switched to servo motors. I have not noticed the tiniest bit of reduction in performance in either of the two machines.

BTW, sewing speed is not a factor in quality, .......ever.

After looking through my post, I realize that, once again, I may have over-answered the original question. If that is the case, I apologize.
 
#3 ·
I too have been sewing since the early 70's. I have three working power stands and about a dozen sewing heads that I swap around depending on what I am sewing. Two of my power stands have clutch motors and one has a servomotor. Either setup is sufficiently strong to do upholstery but I think the servomotor would provide more control for the beginning seamster. Like Dan said, it takes time and experience to learn how to slip the clutch and gain complete control over a machine on a clutch motor, a servomotor gives you that speed control right out of the box.

Ed
 
#4 ·
lamx said:
...... it takes time and experience to learn how to slip the clutch and gain complete control over a machine on a clutch motor, a servomotor gives you that speed control right out of the box.

Ed
Exactly, well put.
 
#5 ·
Thank you both for your insight on servo motors. I will take your advise, the next step will be a servo. But which one? The prices for these motors range from $106.00 on up. Do you fellows have any suggestions on which would be the keepers or which to stay away from? Ironically the price of a speed reducer pulley was $125.00, actually more than a few of the servo motors. I don't want to give the impression that I am shopping for the lowest price. I would like to know who builds the best motor. Thanks again, Terry
 
#6 · (Edited)
Both of my servo motors are Reliable Sewquiet 3000. They have more adjustment than most other servo motors and I love them. They cost around $150, 3 years ago. I'm sure they are more now, but to me, they are worth it. I use them every day, and have not had the tiniest bit of problem with them.CLICK HERE

BTW, you don't need a speed reducer pulley, (also called a variable speed pulley) all you need is a plain old pulley (sheave) half the diameter of the one that's on your clutch motor now. The smaller the pulley on the clutch motor, the slower the speed of the sewing machine. Once you get used to a slower speed, you can start putting larger and larger pulleys as you become more experienced. You can get one for less than $20 at most full service hardware stores. You may need a shorter belt if you don't have enough adjustment to compensate.
 
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