Recommendation - Jack Jk-561A-1 Servo Motor

[laether]

6 hours ago, Constabulary said:

I bought both motors from them - haven´t found them any cheaper.

Alternatively check HOHSING servos:

http://www.bernkopf.de/Motorentechnik/Ho-Hsing-DC-Motor/

They are of a higher quality afaik but I have no experience with them.

Another UK supplier - they have both brands:

https://www.ae-sewingmachines.co.uk/accessories/motors-and-accessories/servo-motors

thanks! will check these. one more question:

how does one adjust the belt tightness on "Jack Jk-561A-1 Servo Motor"? there must be a general way how its done with servo motors?

[dikman]

If you look at the G40 in Constab's second link you'll see a long threaded bolt down the front that is used to adjust the belt tension. It simply raises or lowers the motor around the pivot on the mounting. Pretty much the same for all servos.

[uli12us]

I have bought one of these 750W Motors just 2 weeks ago from www.kornetshop.com.  

It called there JM-822/750 and cost 172€ +5€ shipping. The same part in Ebay is 195€.  Except different connectors and namedplates it seemed, all of this Motors comes from one or 2 chinese factorys. If one would buy it from china, they are much cheaper, but it can last weeks to months, til you get the Motor.

I need it for another machine, so I have tested it, it runs with a potentiometer/rheostat (don't know which word is better) and runs from 103rpm (not really it sounds bad) from 300rpm it sounds how it should be. It works up to 3900rpm, maybe constabs Motor runs at fast, if the maxspeed is changed within the parametre list.

 

 

[Ski]

Has anyone found a way to run this motor + NPS with a reducer?  Maybe even 2:1 ?  Or maybe with just a smaller motor pulley?  Im trying to find the limit of the NPS without spending too much money on pulleys experimenting. 

[Constabulary]

I haven`teven tried to find out more - I just removed the NPS and I´m good. You can turn of the NPS.

[uli12us]

I don't understand, why the NPS shouldn't run with a different gear ratio. The NPS-Sensor is only an rather rough optical encoder.

On one track you have only one slot, for either Needle up or down, that depends on the programm of the Motor. the other track(s) say the controller, how fast is the motor running.

Because the encoder is coupled with the handwheel of your machine, and that handwheel is 1/1 with the needle position, it must work with every possible

gear ratio.

[dikman]

There have been one or two posts about NPS and reducers. It appears that some servos will work with them and some won't (the NPS on my Skyrit servos won't work with any combination of reducer added). Only way to find out is to try it.

[JJN]

5 hours ago, uli12us said:

Because the encoder is coupled with the handwheel of your machine, and that handwheel is 1/1 with the needle position, it must work with every possible

gear ratio.

The problem is with the programming logic of the controller. If the speed reducer causes the motor to turn too many revolutions without getting either a needle up or needle down signal from the encoder on the sewing machine, it gives up thinking that an error occurred. The number of revolutions of the motor that controller will allow without a position signal varies from one servo motor to the next.