Show & Tell: Thumb Controller For Needle Positioning

[Uwe]

I've been wanting to install a retrofit thumb control knob for needle positioning on one of my machines ever since I saw it on that new Adler 969.

My Tacsew T1563 made a good candidate to try a few things out, and it actually works!

The entire project of installing an Arduino controlled high-torque precision step motor drive is rather complex and I'll post more details later.

This video is just about how the thumb control knob works:

[TinkerTailor]

That is REALLY cool, I would have the jog wheel programmed a little different myself, but that is the beauty, you just change it in software. I would add a button or two. One to put the needle buried, and just rising, perfect for turning and one to place the needle up, right where it is easiest to remove the work.

I do like how you can set it to a position, and click for a whole stitch.

It is awesome to see more modern technology that is commonplace in other industries applied to sewing machines. Clutch motors are basically the same technology used in steam powered line shaft shops. Machinists even put vfds on drill presses now they are so cheap and steppers are everywhere with cnc, and cheap. Bout time someone started making this kind of stuff for sewing. I know how all that electronicalistic mombo-jumbo works, However i choose not to tinker with it myself. I'll leave that to you.

One question, Are you going to make a stepper stitch length adjuster to hit the corner exactly?

[dikman]

Brilliant! Can't wait to see the rest of it. (Speaking of steam-powered, the sound your machine makes when it's starting up is a bit like an old steam train wheezing as it first starts ).

[Uwe]

That sound may be me wheezing.

I actually had to turn down the sounds of the original video almost entirely because the step motor makes and infernal racket at slow speeds right now. It's dead quiet when stopped, and has an agreeable hum at high speed, but low speeds are a very disagreeable racket right now. The motor is just clamped to the table top for testing and every slow step it makes acts like a speaker coil with table top pretending to be a sound board.

The programming is indeed a big part of how the button (or any part of this motor drive system) behaves. Arduino programming is fun in a very geeky way. I just knew those engineering, math, and computer science degrees would come in handy some day! I plan to add a little touch screen to allow changing parameters and such.

I actually LOVE how well the speed pedal works. I'm using a modified Ernie Ball brand musician's sound effect pedal to control speed input:

Not exactly cheap at around $70, but it's by far best, most gradual and precise low speed control I've had so far. None of this weird optical gradient hacking, just hundreds of usable, gradual steps of speed input.

I initially bought the pedal to control a Variable Frequency Drive controller, but those 3-phase inverter class motors are wicked expensive,huge, and heavy. The pedal works perfectly as an Arduino input device and it's beautifully made, almost carved from solid aluminum.

[TinkerTailor]

I agree 3 phase motors are expensive, I use the drill press example cause many of the big ones have them already, hooked to a step pulley belt drive and/or gearbox to change speed. A twisty knob is way easier.

[Gregg From Keystone Sewing]

Excellent video, thanks for sharing.

[TomG]

Fantastic. Did you do the design/programming yourself or find instructions elsewhere?

Would it work on any of the servo motors like the Consew?

[Constabulary]

nice idea again but my right hand on the hand wheel can do the same I think...

[TinkerTailor]

nice idea again but my right hand on the hand wheel can do the same I think...

Yes the jog wheel is really just a mini handwheel. It is the "click to stitch" functionality that is the key and the foreshadow to the other functionality this setup has. It is an incredibly powerful computer for the amount of data and control involved with a sewing machine, and the programming support in the CNC machining world is immense.

Now that that functionality has been proven, the controller is open to many other variables like programmable speeds and stitch counts.

If you are in production, you could measure a seam, work out the number of stitches before the next turn, lets say 100, and then tell the machine to go slow for 10, ramp up and rip the next 80 and then slow down for the corner, stopping with the needle up 1-2 stitches from the corner to allow the user to place the stitch perfect. Stitching runs of belts this could be really nice.

There are so many ways this can go. It is basically 1/3 of a fully cnc sewing setup. The other thirds are stitch length/feed control and material steering.

The motor is pretty universal and machine independent, however controlling stitch length and feed is very machine specific.

And you still need someone to steer.

In reality, full CNC is going to be a pain in the donkey for the types of work most on this site do.

The needle position part Uwe has conquered is the most useful for the small project sewer.

The second part, stitch length automation comes up much less often as a need, and probably would seldom get used. The lever is right there.

For the third part, having the machine steer the work for you takes all the fun and fear away........Might as well order leather stuff from china...

[dikman]

I agree in that the needle positioning is potentially of great benefit, the rest....? While it would be very impressive in its implementation, I see little practical use for what most on this forum appear to use their machines for. And yes, in my opinion it would start taking the fun and enjoyment away. I can, of course, understand why Uwe would want to do it.........mainly because he can!

Uwe, my servos make assorted noises at very low speed, the worst is the one fitted to the Pfaff, this one has a small pulley on the motor and an 8" on the machine, and at very low speed it grumbles along and at a particular speed almost seems to create a resonance with the table!! The one on the Singer 211 is connected via a speed reducer setup and this is quieter at slow speed. I'd say that the reducer has the effect of allowing the motor to run a little faster but still give low overall machine speed so is happier because the revs are up a bit. Makes sense to me, at least.

[Uwe]

I'm just the nerdy little kid at the science fair where most people shake their heads as they walk past the display and only a few pause to nod in appreciation.

The project is really about solving the engineering puzzle of building a programmable, computer controlled motor drive system from scratch to learn how these technologies work. I enjoy solving engineering puzzles like others enjoy reaching the next level in Candy Crush Saga.

I'm not expecting other leatherworkers to actually do this. I wanted to show a practical application of an Arduino based controller for powerful stepper motors with fingertip control. It's mainly a contribution to encourage folks in the Arduino and Maker community.

I also wanted to have a functional motor drive system that behaves exactly the way I want it to with precision and power, and to be able to teach it new tricks with just a few lines of software code.

It's not marketable for various reasons. It's also not adaptable to make the current crop of servo motors (let alone clutch motors) behave like this. It's not a DIY project for the masses, but rather for the very geeky few.

I pieced things together from various sources, including Arduino Sketch software code snippets to interpret the rotary dial's grey-code signals. The hardware was sourced from my local music store, Ebay, Amazon, Adafruit, etc. I'll do a more detailed write-up and video with parts lists and software code over the next week or two.

[LumpenDoodle2]

This looks a fascinating project. I'm not a very techie nerdy, but I can appreciate nerdiness in others.

I would love to hear more about this.

[dbusarow]

I pieced things together from various sources, including Arduino Sketch software code snippets to interpret the rotary dial's grey-code signals. The hardware was sourced from my local music store, Ebay, Amazon, Adafruit, etc. I'll do a more detailed write-up and video with parts lists and software code over the next week or two.

Uwe,

I'm looking forward to the write up and parts lists. This looks like fun.

Dan

[Constabulary]

Hope you did not get me wrong - I seriously like your ideas. I was just thinking about the purpose. Anyway I´m looking forward to your next project and will follow this one as well!

[gottaknow]

Well done Uwe. There are applications in a factory when this is needed. I could give plenty of examples, but suffice to say most high end control boxes have an output plug just for this purpose. We call it jogging. I can either mount it near where the operators hands are or sometimes on a knee switch. It is an absolute must on a memory stitch machine while programming a new pattern (we set all of our woven labels on a Brother memory stitch machine). The oldest one I have is on a Union Special coverstitch machine used for doing elastic waistbands. It's from the early 80's.

So at some point, someone got their geek on and came up with this for apparel manufacturers. Nothing advances in my industry unless there is a need and a market. Keep tinkering.

Regards, Eric

[Darren Brosowski]

My good friend - ex girlfriend - has been in the sewing industry for nearly 40 years and she started off in a factory with 100 year old machines run off a common shaft under a bench running 6 machines.

Over the years she has done everything from high speed mass production through custom fetish wear, pattern making, custom clothing and one off period corsets

She mostly uses high speed machines and has five different industrial machines but when she wants to do a job with absolute control she jumps on one of her treadle machines.

You can spend thousands to achieve the ultimate electronic control or you can just run the machine on a treadle base and adjust the speed to the work without moving your hands.

.

[gottaknow]

I wanted to share this with Uwe so he could see an application where a needle positioning "jog" button is used in a production setting. The machine is a Union Special 34700. It's a 3 needle coverstitch machine used to topstitch stretch waist bands. We most recently used it for some high end equestrian riding britches. A coverstitch machine produces a very stretchy stitch. It has 3 needles and 1 looper. There's no backtacking with a coverstitch, so a precise overlap is required. The jog button allows the operator to make a very controlled tie in. Elastic has ribs, and you have to stay in the same rib with the needles to secure the seam. In the picture, the small green button is plugged right into the control box. This is a Tele Dyne motor with using a Quick Rotan control box. The feature gives the operator complete control of the overlap.

Regards, Eric

[TZBrown]

I also like geeky stuff. That is pretty cool.

I probably don't have the drive to develop anything like that but I do appreciate the function and can see the uses for it

[Darren Brosowski]

All of the geeky stuff is great in the right place.

For the speeds that people want to run a 441 they would be better off with a treadle.

The motor that gives the perfect control costs nearly as much as a 441 machine head.

[Hockeymender]

All of the geeky stuff is great in the right place.

For the speeds that people want to run a 441 they would be better off with a treadle.

The motor that gives the perfect control costs nearly as much as a 441 machine head.

That's not even close to accurate. Mine came set up with a servo and a speed reducer and I can run that one stitch at a time. The motor price did not rival that of the machine head. I would hate to think of trying to be precise with a treadle on that type machine.

[TinkerTailor]

That's not even close to accurate. Mine came set up with a servo and a speed reducer and I can run that one stitch at a time. The motor price did not rival that of the machine head. I would hate to think of trying to be precise with a treadle on that type machine.

He is talking about the kind of stepper motor Uwe used in his project. They cost alot more than a servo. No normal sewing servo motor is arduino controllable,.....yet.

That would require some scoping and reverse engineering to do, and in the long run is not as configurable.

Hey Darren, while a treadle would work for most, some of the leather workers around here have issues with the lower body, and are unable to operate a treadle. This hand control system could prove immensely valuable to someone with special needs. Ever seen a hand control converted car? Not a cheap process but if that is what is required to get your mobility back, you do it. I agree that this is a limited market project, and Uwe is fully aware and has stated such. He does not care it appears, this is just for fun primarily but with known potential for actual usage.

Sometimes you take the path that you know is a dead end, just to see the sights along the way.

[gottaknow]

As I stated before, the push button needle positioner isn't something new. It has been used in factories for at least 40 years. It's an option on new Juki control boxes including their new direct drive top shaft mounted motors. You can't really judge its value until you've used it. Granted, these are high dollar control boxes with around 100 programmable features that you'll never find on any of the aftermarket control boxes talked about in this forum. I don't have to tweak speed controllers with cardboard and tape. I can see the benefit of the jog feature on leather machines as it gives absolute control. I don't care how skilled you are with a treadle or your hand on a hand wheel.

Regards, Eric

[Uwe]

I put together some more details on the Arduino step motor drive setup for those who are interested. I know this is not everybody's cup o' tea. Feel free to ignore if it chafes you or you prefer a clutch motor or a treadle.

A few pictures to show the overall setup:

The stepper motor itself is quite small, actually, considering how powerful it is ( 3 Nm torque):

The pulleys are XL type timing pulleys with 20 teeth (motor) and 40 teeth (machine) for a 2:1 ratio

The motor is mounted using a bracket in the original belt slot. I used rubber pads to reduce vibration noise somewhat:

The motor drives the machine with a 11mm wide (XL size) timing belt:

The thumb dial and rotary encoder

The controller bits still set up in a test configuration, not yet neatly packaged:

The Pedal is actually the most expensive part at $65. It also needs a return spring.

The main parts used for this project ran about $225 total:

Step Motor (23HS45-4204S) $50

Motor Bracket $15

Arduino Uno R3 $10

24V 250W Power Supply $20

Step Motor Controller (ST-M5045) $35

Pulleys & Timing Belt $25

Thumb wheel & Encoder (Adafruit) $5

Pedal (Ernie Ball VP Jr. 25K Ohm) $65

I've made a shopping list on Amazon (large pulley in the list has a 10mm bore, my machine takes 12.7mm, i.e. 1/2") The prices don't quite match up because I had ordered some bits through Ebay directly from China at a lower cost.

The Arduino Sketch Software Code is available as a text file to import into an Arduino Sketch window. The Code is commented to explain what's going on.

The wiring diagram (also available in high res) - there went five hours of my life ...

[stelmackr]

Thanks, I'll have to drag out my old programming books....

[dikman]

Very impressive bit of work, Uwe. (Don't take this the wrong way, but the closeup of the thumb dial isn't pretty (!) and the soldering on the next one looks a bit so-so (or is that just the photo?)). Nothing personal, I just tend to notice these things.