my new consew 206RB-5 premier 550 variable speed servo motor-speed control

[Gudmundur]

My 132K6 came with a danish clutch motor that I had no way of controling the speed of. As I looked for a solution I came up with this servo motor. I had looked at speed reducers, but as the clutch motor has a rather large wheel I decidet for the servo motor. It did not disapoint me, it starts and stop rather smoothly. No jolting, I wrote before that it has lower limit of 300 rpm, that is not right (my bad) It is adjustable so that max speed can be 300 to 3000 rpm. From zero to what ever I decide. And as the wheel is just 65 mm it works well.

Now I have to work on the sewing machine as there are some things that need adjusting.

Best wishes

GK

[Wizcrafts]

1 hour ago, Gudmundur said:

My 132K6 came with a danish clutch motor that I had no way of controling the speed of.

Most clutch motors have a big bolt on the right end, in front of the output shaft, which can be adjusted for more or less free play. This free play works with a coil spring that causes the control arm to stay up until you push down on the floor pedal. Tighten up the coil spring to make sure the arm is all the way up in idle, then back off the adjustment bolt until you have enough slack/free motion to feather the clutch.

If the motor wants to go off to the races despite your adjustments, place a tennis ball under the toe end of the floor pedal. Then buy a smaller motor pulley that fits the shaft on the motor and a new v-belt to match the longer reach. If the motor is still grabby, open it up and smear a thin coat of light grease on the clutch pad to let it slip a bit. Unless you have restless leg syndrome, you should be able to learn to feather the clutch for slow speed operation. It's the same as driving a clutch car.

[Gudmundur]

Thank you very much for this information, unfortunately I already have given the old motor away, and mounted the servo motor. But I will most certainly remember this in the future.

As a matter of fact I have rls but that does not bother me when awake, and when sleeping the wife has forbidden me to operate the sewing machine  

Best wishes

GK

[Gymnast]

On ‎8‎/‎15‎/‎2019 at 1:35 PM, Gudmundur said:

This is a interesting topic to me, because I just bought a servo motor from a polish company. The motor is Texi ac 750 SM with a synchronizer for up or down needle stop. I installed the motor on my old Singer 132K6, so far I understand the motor has a lower limit of 300 rounds pr. minute. And a upper limit of 3000. It took five days to reach my home address, with a weekend counted in. 

Best wishes

GK

I hope, that the motor should be able to turn at lower speed than 300 RPM. It seems to be a high speed to me.

This link is to a dealer of what I think is your motor:

https://www.strima.com/texi-power-750-sm-ac-servo-motor-with-synchronizer/item/1047899 

Another guy, DanishMan is sometimes around this Leatherworkers forum. He uses another polish servo motor from Zoje, and recommend it: 

https://www.sewtex.de/Motore--Gestell--Tischplatte--Zubehoer-fuer-Naehmaschinen--Stuehle--Leuchten--Transportwagen--Industriestuhl--Schere/ZOJE-TZ-ZJ750W-S-Servomotor--Naehmaschinenmotor.htmlhttps://www.sewtex.de/Motore--Gestell--Tischplatte--Zubehoer-fuer-Naehmaschinen--Stuehle--Leuchten--Transportwagen--Industriestuhl--Schere/ZOJE-TZ-ZJ750W-S-Servomotor--Naehmaschinenmotor.html

When I compare the Pictures, they look the same, and I suspect they come from the same Chineese manufacturer. However important software can be different.

I found and read this link to some service information on a servo motor from Zoje:

http://files.zoje.com/uploads/doc/WR596 training.pdf

I guess, it is the same motor, but I am not sure. But this service information reveal a motor and control unit, that is designed for sewing machines. Its is a well designed motor drive and uses a brushless DC motor. It is not just a modified industrial multi purpose motor drive.

In order to control a motor like that at low speeds, you need a bit more complicated software in order to avoid too much ripple in torque. Furthermore you need to measure or estimate the temperature (by software) of the copper windings in the motor, because the blower on the motor shaft cooling the motor is not effective at low speeds.

I made this thread in this forum to show off my "home made" speed control of one of my sewing machines. I did that, because I suspect, that some leatherworkers speed control are not well designed, and they should see what is possible:

https://leatherworker.net/forum/topic/86489-do-you-like-this-speed-control/

[Gudmundur]

Hi Gymnast

Yes iI bought the motor from Strima, and I did not formulate myself right, about the speeds. The max speed can be adjusted from almozt zero up to 300 to 3000 rpm.

I am quit satisfied with the motor so far.

Best wishes

GK