beefy

Thanks for explaining that AIZilla. Had a little laugh with what you said, "Simple to do, but apparently takes a lot of words to explain..." That's just like the programming of my needle positioner. Seems such a simple task yet the coding takes a lot of time and focus, and keeps getting longer.

Hi Toxo, Thanks for posting that picture. I might actually use the design method of that one to make my own but with magnetic hall sensors instead. Only problem I can foresee is a hall sensor on on disk may pick up the magnet field from a magnet on a neighboring disk. No I've never seen your old type, as I am very new to this industrial sewing machine stuff. I've only seen the ones all over Ebay, Aliexpress, etc. My guess is the sensors on your old one are infra red receiver/transmitter types. What I like about that physical design is it's easy to build (I've got a lathe). Downside is it's a bit more bulky as more position disks are added. Did dust ever cause the optical sensors to work correctly ? Yep, seems many Chinese sellers think the need for instructions is just plain silly. The instructions that came with mine are just completely wrong, and probably based on some other controller. And when you hassle them enough to give you some instructions it's still terrible and not complete. That's what has made me give up on them and play with this idea instead.

Cheers AIZilla, interesting suggestion. I'm just a beginner at this sewing gig and all the videos I've watched start of sewing forward then backstitch then forward again and continue. Would you only start off backstitching with leather but not fabrics, vinyl, etc.

Thanks for the suggestions Nejcek74, yes, using an Arduino Uno or Nano for this one. I normally use these boards but program in straight C using Atmel Studio, but for this simpler project will just use the Arduino IDE and "Arduino C". Also adding an external mix of operational amplifier circuits basically because I'm unsure of how the "analogue" output from the microcontroller would affect the servo. Op-amps will give nice smooth variable DC signals. The basic principle is my system will simply "go between" the foot pedal output and the servo speed command input, and "take over". It will monitor the foot pedal output as well as the heel switch, monitor the outputs from the needle positioner, and command the servo to do things accordingly. So basically the servo is nothing but a driver for the motor and it's not even aware a needle positioner is installed. The servo simply does what it's told by my controller, pretty simple really. The most difficult bit is getting the programming correct and foreseeing all the situations that COULD happen. It's so easy to find things afterwards where you say, "Oh yeah, I didn't think of that condition existing at some point" LOL. I've pondered the idea of a DIY needle positioner disk, where I can have more than 2 sensors IF there's any benefit to having more than just a needle UP and a needle DOWN position. The rotating disk itself would have just one magnet glued in a hole in the edge. Hall sensors around this disk can be moved to any position to have the needle stop in exactly the desired position. For now though I just want to get the basic design working with an off the shelf positioner. Got one arriving mid January. Never thought of the idea of automatic back stitch control, good suggestion. I like that one and it could be my next quest. Will have to work out an electrical way to operate the reverse mechanism.

Thanks Dikman, yes this design will be specific to my setup, but my setup is a typical Chinese servo drive, so any time I get a new cheapy servo, if the connections are not identical, I will be able to easily modify them to suit. You are right, I don't need this so much for very slow sewing but it will be great for other things when I'm going faster. I'm also finding as I'm learning to handle say tarp material or a canvas cover, not having to concentrate on the needle position will make life much easier. I'm also going to make my backstitch foot control so my hands will be completely free nearly all the time. To be honest this is more a labour of interest rather than a huge necessity. I get very engrossed in the design and programming and the hours tick away quite quickly. And when the design is completed (and works LOL) I enjoy it every time I use it.

Thanks Fibresport, the servo IS what normally does the control when it receives the signals from the synchroniser, but my design will command the servo drive based on the needles position. I've already paid for 2 motors and drives so don't want to buy 2 more LOL. Plus I enjoy this design work and it will be very cheap.

In keeping with my growing love of my newly acquired industrial sewing machines, I'm now getting myself absorbed in designing an electronic circuit and programming a microcontroller to make my own needle positioner. I've given up trying to get any sensible instructions for my cheap Chinese servo from the seller. I know it also doesn't have any heel press functionality. So far this is the functionality I'm programming for it: Single revolution/stitch from EITHER the needle UP position or needle DOWN position. This is done by a quick tap on the pedal, either forward (for needle DOWN) or heel tap (needle UP). Stop in needle DOWN position when foot pedal released. Go to needle UP position when heel tapped. Adjustable "coasting" speed when searching for either needle UP or needle down position. This is to have control over overshoot if servo cannot stop motor fast enough. Search for needle position is cancelled if operator presses foot pedal while motor is coasting and waiting for needle UP or DOWN signal. Safety feature - adjustable timeout for motor coasting and looking for needle UP or DOWN position. Coasting stops if signal not received within timeframe. This prevents the machine going on forever if some fault occurs like a broken wire, or faulty needle positioner. Are there any other useful features a needle positioner could have ?

No I don't have a needle positioner installed. The first thing I was wanting to do was check I can actually access the settings for the needle positioner, hence me starting this thread. However, yesterday I order a needle positioner because even if my servo supplier cannot give me the instructions I can still design my own interface for needle positioning (using the off-the-shelf needle positioner) and it will have better functionality than what my servo drive has. Example my foot pedal controller does not have any switch for when you press back on the heel of the foot pedal, and I check the wires from the foot pedal controller and there's only 3 which will be +5v, 0v, and the variable signal from a potentiometer. No wire for a signal from a pedal heel switch. So looks like my servo is very basic and doesn't have this functionality built in.

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. NEEDLE POSITIONER PROGRAMMING.mp4

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.

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.

Absolutely nothing. I've tried pressing it for various periods of time, up to over 10 seconds, and nothing changes.

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

Thanks very much guys. I found pinouts for another servo brand on this thread so I checked mine and I got +5v at pin 2 of the needle positioner connector (referenced to pin 1), so it appears this may be a standard for these types of drive. I've sent a message to the Ebay seller telling them I cannot access the needle positioner settings so I'm currently at the mercy of their service and knowledge of the product they sell. According to the pinout on the above referenced thread if I can access the settings I may be able to test the positioner operation with a simple switch to inject signals onto pins 3 and 4. I've attached a few photos of the drive and the instructions. Keith

I've bought a couple of these cheapy Chinese brushless servo drives for my industrial machines. https://www.ebay.com.au/itm/145766877894 They both work (at least for now LOL) and coupled with the 4 pulley reduction systems I've fitted, make life absolute heaven. However, the instructions are the typical useless "Chinglish" where you have to attempt to work out what you are being told. Nothing happens when I attempt to check the needle positioner setting, so my questions are: 1). Is it typical that without a needle positioner connected, you cannot enter the setting for needle positioning. 2). I cannot find a needle positioner in the seller Ebay store, so will any needle positioner that's meant for a brushless servo drive work.

@Handstitched I can imagine you've had that machine for many years. Just been looking at mine today and it looks like it's been used a lot. All the paint is worn off where material has passed over it. The knee lifter mechanism is sloppy as hell due to wear. I think overall it's had quite a lot of use, yet despite that all the mechanical internals seem to have not much wear, and it's stitching great. These old industrial machines, especially the walking foot ones, are very dangerous. You start off getting one for a purpose but then you fall in love with them and want to get another LOL. Got to keep myself under control.

Thanks very much Bob, much appreciated. Some other interesting reading in that manual too. It is rather surprising that with all the clones of the singer, actual real service manuals are almost non existent. Keith

I'm the very excited new owner of my very first walking foot machine, an old Seiko STW-8B, and from what my internet searching tells me, is the exact same model as the Consew 226R-1 (please correct me if that's wrong). The first thing I always do with any new machinery is get all the manuals I can find, but I can't seem to find a service manual for this machine. Anyone got any links. Thanks, Keith