Are needle positioners for brushless servo motor drives all the same

[beefy]

4 hours ago, friquant said:

I see now why you're asking if a needle positioner is required in order for that button to function..

What about the other menu functionality? Are you able to set forward/reverse and min/max speed?

Yes I managed to change the other two you've mentioned. 

Still no reply from the seller, and I can't see any sign of him/her being on vacation. I'll wait another day or so. Supposed to be a very reputable seller.

[1hp]

there are at least two sizes of 4 wire plugs. bought the wrong one first. this instruction sheet may help:

Servo Motor Technician User Manual(v3.7 L-Type 4-Bar for ShuangZheng).pdf

[toxo]

After reading this thread I thought I'd have another go. Another waste of time. Tried every setting with the same results. Everything else works fine except the needle position. No matter what the setting, every time I stop the needle is in a different position,sometimes up - sometimes down and never up/down in the same place either. It goes slow enough that it's more of an irritation than a pain but short of ripping out the speed reducer and replacing the handwheel and motor pulleys, I'll live with it.

[friquant]

2 minutes ago, toxo said:

Tried every setting with the same results. Everything else works fine except the needle position.

What settings did you try for P-15 (Needle Detection Mode)?

[toxo]

18 minutes ago, friquant said:

What settings did you try for P-15 (Needle Detection Mode)?

Which P-15 did you mean? This one?

Or this one?

 

Edited December 28, 2025 by toxo

[friquant]

1 hour ago, toxo said:

Which P-15 did you mean? This one?

In the Stitchman Servo Motor: The Missing Manual

Specifically this part:

 

[beefy]

Ah well, appreciate the help everyone, thanks.

Looks like it's all down to the Ebay seller now, but still no response after 2 days. If they don't respond I'll put a refund request in to Ebay for goods not as described. It does say in the sellers description that a needle positioner can be added.

I've messed around with electronics and programming microcontrollers here and there, so I could always devise my own interface with an off the shelf needle positioner.
Would be an interesting little project but I should really be concentrating on more important things LOL.

[toxo]

6 hours ago, friquant said:

In the Stitchman Servo Motor: The Missing Manual

Specifically this part:

 

Tried it again with no joy. Then it occurred to me that the braking system must come into this. If I'm stitching slowly the brake is immediate and the needle stops wherever it happens to be in the cycle. If I go fast it wil stop in the down position ( where I want it) most of the time.

[beefy]

Well the seller did respond. This is what he said:

Needle positioner setting is adjustable without connecting the needle positioner, but an E8 or E9 error code will be displayed once adjusted.
The code will disappear once the needle positioner is connected.

They sent me a video but it's in Chinese, so I've messaged them back to ask for English instructions LOL. Here's the video in case anyone can make use of it.

 

[toxo]

On 12/27/2025 at 11:33 PM, beefy said:

Thanks Toxo,

initially I had no idea what you were telling me but after seeing this thread and Uwe's reply (post No5) I now understand why this may happen. It's a safety feature of some controllers where they only allow a limited number of turns of the servo motor when the foot pedal is released. The controller is expecting to see the needle positioner signal "real soon" after the pedal is released and shuts the machine down if too many many revolutions pass without seeing this signal.

Of course with the pulley reduction the motor may spin multiples of times before needle positioner signal is seen. With my servo system being el-cheapo it may work in my favour if such safety features have not been implemented LOL.

Keith

You don't say if you have a needle positioner installed but re the amount of revolutions, I think this is where my problem lies. The braking system on mine stops immediately I stop sewing. I know the braking system can be adjusted but haven't looked at it yet. Maybe it needs that little bit of freedom to get to the set position. My Chinese seller is asking me for a video so they can see the problem. I should add that my machine came fully built but without the N/P installed.