Stitchman servo motor.

[toxo]

Does anyone have an English user manual for this motor?

It came with my new machine which is a copy of the Techsew 2750. The motor seems ok and I can get it to start really slowly and speed up on the treadle but apparently it has a needle up and a needle down setting. It came with a normal NPS as well but I can't get that to work properly because the machine has a speed reducer. If someone was really good on this machine they could almost get the needle up/down on the treadle but I can't do it with any consistency. The user manual for the motor is mostly Chinese and the English bits just make me laugh.

Any advice anyone?

Edited April 28, 2024 by toxo

[fibersport]

You most likely will not be able to get the needle postioner to work with a speed reducer.  The simple reason is a needle postioner reads the location of the input shaft of the machine, it is programmed for a particular distance per revolution.  With a speed reducer, that distance per revolution is now changed, the positioner is not designed for the change and therefore can't work.

[toxo]

19 minutes ago, fibersport said:

You most likely will not be able to get the needle postioner to work with a speed reducer.  The simple reason is a needle postioner reads the location of the input shaft of the machine, it is programmed for a particular distance per revolution.  With a speed reducer, that distance per revolution is now changed, the positioner is not designed for the change and therefore can't work.

I appreciate that but the blurb seems to be saying that the motor is capable of needle positioning on it's own. If you look at the picture the two dots above the "P" are for needle up and needle down. I like having needle positioning. On my other two machines I've replaced the handwheel with a larger pulley to slow down the machine which it does very well as well as giving more torque and the normal NPS works very well on both.

I wonder if the normal NPS would work on the motor pulley?

[1hp]

the servo on my Cobra 4 looks same. 

 

 

 

Edited April 28, 2024 by Northmount
Rotated pictures so top is at top and re-uploaded

[toxo]

4 hours ago, 1hp said:

the servo on my Cobra 4 looks same. 

 

Thanks for that 1hp. I'd kinda figured out that much but was thinking was there more to the first part where it talks about needle up/down. Is it saying the motor can do this or only in conjunction with a traditional NPS? Here's what mine looks like.

 

[1hp]

not sure as i do not have an NPS. there are outlets for connecting one though. Leather Machine Co. does sell a class 4 with NPS & speed reducer.

Edited April 28, 2024 by 1hp
more information

[dikman]

Some NP's will work with a speed reducer, but in most cases you won't know until you try it.

[toxo]

52 minutes ago, dikman said:

Some NP's will work with a speed reducer, but in most cases you won't know until you try it.

I think I'm gonna try to fit the normal NPS onto the motor pulley. The machine is perfectly usable and will get better as I get  used to it but I do like my NPSs.

[1hp]

i put a 40mm pulley on the Cobra 4 motor. in conjunction with the speed reducer, it will go really slow.

[dikman]

3 hours ago, toxo said:

I think I'm gonna try to fit the normal NPS onto the motor pulley. The machine is perfectly usable and will get better as I get  used to it but I do like my NPSs.

It will be  fair bit of messing around but worth a try. I don't think anyone has fitted one to the motor before so it will be an interesting experiment.

[toxo]

3 hours ago, dikman said:

It will be  fair bit of messing around but worth a try. I don't think anyone has fitted one to the motor before so it will be an interesting experiment.

Maybe not. Depends on how much thread is sticking out past the securing nut. The aluminium boss that the nps slides onto is hollow. Don't have a lathe anymore but I'll give it a try.

[MML]

Hey did you find a solution to this?

[Samalan]

It doesn't matter whether it's slow or fast. The EPS is connected to the sewing machine shaft; it could make one revolution per day and still work. My machine is so slow that I get nervous watching it, and the EPS works just fine.

[friquant]

On 4/28/2024 at 7:11 AM, toxo said:

Does anyone have an English user manual for this motor?

It came with my new machine which is a copy of the Techsew 2750. The motor seems ok and I can get it to start really slowly and speed up on the treadle but apparently it has a needle up and a needle down setting. It came with a normal NPS as well but I can't get that to work properly because the machine has a speed reducer.

 

I have the same servo motor. The paper manual shows the wrong values for the P15 settings. On mine P15 actually needs to be set to "0" to enable the needle position sensor.

Here are my notes on this servo motor, which may reasonably constitute an English user manual, with some missing pieces.

[toxo]

On 6/19/2025 at 6:05 PM, friquant said:

I have the same servo motor. The paper manual shows the wrong values for the P15 settings. On mine P15 actually needs to be set to "0" to enable the needle position sensor.

Here are my notes on this servo motor, which may reasonably constitute an English user manual, with some missing pieces.

Since setting up my machine I've got it working so I can use it easily and so haven't look at the finer details but I have to say something that's on my mind before I forget it.

If you take the cover off the normal NPS there are two serrated discs and they have gaps in them which stops the motor. You can get the needle where you want it and then turn the disc to suit. One disc for needle up and one disc for needle down. I used this method for a long time until I got this new one which has a speed reducer. What I've said here doesn't seem to work with speed reducers but if yours doesn't have one it might be worth a look.

[MML]

@toxo Were you able to get the NPS to work with the speed reducer with one of the P settings? I have not been able to get it to work

[toxo]

5 hours ago, MML said:

@toxo Were you able to get the NPS to work with the speed reducer with one of the P settings? I have not been able to get it to work

Let me start by saying my machine doesn't get an awful amount of use. The short answer is no but that's because I haven't tried. I usually use it on a slow  setting and I find it easy to get the needle where I want it with small movements of the pedal or the handwheel. Maybe I'll have another go at it sometime later but at the moment I've other stuff on my plate including a very poorly dog.

I will say that I'm impressed with the machine. I've just stitched both sides of a 60 inch strap on 20 and it didn't bat an eyelid. Can't say that of other machines in the past.

[MML]

3 hours ago, toxo said:

Let me start by saying my machine doesn't get an awful amount of use. The short answer is no but that's because I haven't tried. I usually use it on a slow  setting and I find it easy to get the needle where I want it with small movements of the pedal or the handwheel. Maybe I'll have another go at it sometime later but at the moment I've other stuff on my plate including a very poorly dog.

I will say that I'm impressed with the machine. I've just stitched both sides of a 60 inch strap on 20 and it didn't bat an eyelid. Can't say that of other machines in the past.

Good to know. It seems like NPS with the stitchman servo motor and a speed reducer is not possible. If anyone finds a way to get it to work, please let me know!

My only motivation to have one is that with a speed reducer the wheel is much harder to move by hand, so it’d be nice. 

I do agree it’s not necessary at all with a speed reducer. 

I only wish the engineering was a bit better. The NPS knows the needle is not in the correct position, so i don’t understand why it would not tell the motor to keep going until it’s in the correct position (with the light on). Does anyone know how it’s working under the hood that it’s not agnostic to revolution size? @friquant, would you know?

 

Thanks.

[MML]

I just got it to work! 

@friquant’s mention of setting P-15 to 0 (it’s 1 by default) makes it work for me to always have the needle stop in the NPS’s programmed position (the range of the NPS’s light being on). 

On the manual @friquant put together, P-15 set to 0 seems to tell the machine to listen to NPS and the needle position. I’m not sure if without the speed reducer it would work with the other setting. 

It shows Er01 on the screen most of the time, but it’s consistently working.

All you need to do is: 

Hit “P” & “+” until you get into program mode.

Hit “+” until you get to “P-15”

Hit “P” to go into the setting. At this point you’ll see it show “1” by default.

Hit “-“ to bring it down to “0”.

Hit “S” to save the setting.

Use the “needle up setting” 

 

Good luck!

 

[friquant]

@MML Glad to hear the needle positioner is working for others too!

I added a reply to the manual that shows how to access the hidden menus. The most useful piece so far is being able to set the upper bound on max speed.  🐎😀