Help With A Servo Motor

[Constabulary]

Are "brushed motors" really servo motors? I thought servo motors always have these rare earth magnets or coils. I just ask because I`m not sure.

Brushed sewing motors are very common over here. Moretti, EFKA, ELTE, Pfaff and so forth produced these for decades. They were called "Anlassermotor" (but a 1:1 translation may not make sense) I just have two of them flotation around. I always liked them (some more - some less) The power is not electronically controlled. They have a stack of contacts instead and the further you push the foot pedal the more contacts are touching each other and so the power is controlled. (I do not mean clutch motors)

So does the fact that a motor is electronically controlled make it a servo motor?

Edited February 22, 2015 by Constabulary

[Colt W Knight]

The term servomotor encompasses a lot of different motor designs and can be brushless or brushed.brushless motors are more expensive. The feedback device and electrical controlare really what make it a servo motor.

[Bertil]

Wikipedia has a good article about servos http://en.wikipedia.org/wiki/Servomotor

I guess that the "Anlasser motor" is a stepper motor.

Edited February 22, 2015 by Bertil

[xs400]

...and when you get it, here's a thread to make it run even better with more control.

http://leatherworker.net/forum/index.php?showtopic=55723&hl=

So, I got the Family Sew FS-550s. I read this thread that you recommended and uh....well, I will admit that I failed my circuits class the first time I took it. All of that read like instructions to perform brain surgery in Sumerian. I guess I will just rig up a speed reducer to get more control.

It seems as though there is a small window on the slowest speed that will go slow and steady. It is hard to regulate because of the torque issue.

I am making seats for motorcycles and I need that steady slow speed that we all want for that beautiful, not so cheap leather we bought.

I appreciate so many of you filling me in on this stuff as I am new to the compound feed machines.

What do you guys think?...Better to buy a speed reducer or make my own?

[Ole South]

Maybe some of the more experienced guys can chime in here... I'm curious too. Can we modify the opto-interrupter on the FS-550 like the Enduro to gain a longer acceleration ramp?

[Bertil]

Re Enduro they have changed it on the 2nd generation. I have an ENDURO PRO SM645-2P 220V and it works like a charm on low speed. Read my review and comments http://leatherworker.net/forum/index.php?showtopic=61436. This machine would run on slowest max speed 100 rpm and with a 50 mm pulley and 100 mm hand wheel 50 stitches per min. Still you have the possibility to go very slow and have the torque and control. What I find very convenient is that you can easily turn the hand wheel without pressing down the foot pedal.

Re Family Sew if you really want to keep to keep it: Go with a speed reducer. The motor is really not made to run at slow speed. Then it just matters how handy you are if you buy a ready made one or make one yourself. Search for speed reducer in the forum and you will find a lot of good ideas if you want to make one yourself.

[Ole South]

Ooops.... I should have read ALL the links in the preceding posts. JoMama and BDaz have a handle on this motor.

XS don't be too intimidated by what you read. These guys have outlined two modifications that will allow you to fine tune your servo motor. One gives greater control limiting the high end speed and the other describes how to control how fast the motor reacts to the foot pedal, with the additional benefit of moving the control up top so it's easier to change! If you're tied into the bike scene I'm sure there's someone locally that can guide you along the way.

[Cobra Steve]

We put speed reducers on all of our machines. We have found that using an actual pulley system along with a servo motor you get better control so whether you make your own, or buy one, you will b better off. Our servo motors also come with a 3 year warranty and our speed reducers have a lifetime warranty.

[Wizcrafts]

I have one machine that is powered directly by a FS-550 and another with a FS-550 going to a 3:1 speed reducer, then up to the machine. Both motors are fitted with 50mm pulleys and are unmodified.

The direct powered machine has a maintainable slowest running speed of about 1.5 stitches per second. But, it is trivial for us to do single stitches and stop needle up or down.

The other machine, with the reducer, can actually be kept at the blazing pace of one stitch in 10 to 12 seconds (it has a bigger flywheel pulley). The only practical use for such a slow speed is to watch exactly where the needle is going to hit, which is useful when doing repairs to previously sewn work. More useful is simply turning the speed limiter switch to the slowest setting and flooring it. This gives us a steady speed of one stitch per second. This is useful when I sew fishtails or other patterns onto belts and straps.

In hindsight, I should have had a speed reducer installed on the other machine when I ordered it. Adding it on now will require repositioning the bobbin winder and possibly enlarging the belt slot in the custom cut table.

Do I recommend speed reducers for leather sewers? You betcha! The ones now for sale from our member-dealers should all have ball bearings, rather than the old style sleeve bearings. If you are buying a new sewing machine and the dealer offers a speed reducer installation option, take it. You'll save yourself a lot of trouble later on.

[JoMama]

I bought a speed reducer that looks like THIS one and it was a pain to install because you cannot tilt your machine back since the drive belt is no longer in line with the machine tilt pivot and machine pulley.

I suggest getting one of THESE since it will save you at least $100 worth of headache. I wish I had. You will not have to cut a bigger slot in your table either.