Hi fellows, i need really help.My problem is I need to detect when the bobbin is used by the machine.I can't pass the thread through a sensor.
When a machine taking thread of bobbin the thread doing circles because bobbin's shape is conic.A full bobbin is about 300mm diameter.And a nearly empty bobbin is about 40 mm diameter.The threads are very thin.
I think if i can make or buy a sensor in the range of 300mm diameter to zero or at least 40mm diameter, i will put that sensor to conic bobins lower end.
There a many bobbins working near and the sensor may not take other bobbins movement.
Can you recommend me a sensor or modify a sensor to do it?
Can a laser distance sensor(like CJMCU-530 VL53L0X ToF) catch the thread?while it thread making circles and away from 15cm's?Or a pir or microwawe sensor?
@CrossRoads thank you for the reply.And i seeing your messages around thank you for the helps you did you have a very good knowledge.
I have that sensor but i dont think it will catch the thread but i will test in a couple hours.
And i just want to clarify that a dont want the diameter of bobbin i just want to know machine is using thread.But if i detect the diameter while thread is speedly drawing circles it is a sign of its running anyway.Just saying for the distance of thread not important.Imported thing is movement of thread.
Is there a reason you can't pass the thread through a sensor? There are sensors made for knitting/weaving machines just for that purpose. I suppose you could make your own sensor, put an IR source on one side of the thread, and a pickup on the other, with an amplifier sensitive enough to pick up the variation in IR intensity caused by the variations and vibrations of the yarn. I've also seen sensors that ran the yarn over a wire attached to a piezo element that would pick up the noise of the yard running across the wire (basically like dragging it across a sensitive microphone), but that type requires contact with the yarn, while the optical sensors just have the thread pass within the sensor without touching it (although you usually have the thread passing through guides to position it correctly).
@Robin2 video on top.For the optical sensor idea the best is putting sensor to middle of bobbin the place that i showed.because if i put a sensor under the yarn bobbin i have to make a place for it.But i will be use if there is no way.Are you thinking like david's idea?
And i dont want to detect the broke of thread, just want to is it running or not, thank you for reply.
@david_2018 thank you for the reply, yes i know there are optical sensors in knitting industry, but they are working with machine, and just telling the machine there is yarn in me.not the yarn is flowing.or the yarn is moving.i attach a youtube video can you check please?
For the IR sensor like robins idea the best is putting sensor to middle of bobbing the place that i showed.because if i put a sensor under the yarn bobbin i have to make a place for it.But i will be use if there is no way.
I can't attach anything on the yarn for piezoelectic idea.What if I put a condenser microphone on the inside of the bobbin and that microphone touch the bobbin and listen to the sound?
Thanks for the video. It looks like the bobbin does not rotate - I had been assuming that it does.
Your idea with the "propeller" looks like it would be worth pursuing. It could probably be used in conjunction with an optical sensor - either the reflective type (the QRE1113 is small, but easily soldered) or the beam-break type.
I suspect you would need a hardened (and polished) steel "propeller" as my guess is that the thread would eat into plastic very quickly. Maybe you could 3D Print the propeller and fix small sewing needles to the edges that contact the thread.
Can you post a video of the other end of the thread in case there are better opportunities for monitoring there.
Robin2:
Your idea with the "propeller" looks like it would be worth pursuing. It could probably be used in conjunction with an optical sensor - either the reflective type (the QRE1113 is small, but easily soldered) or the beam-break type.
I suspect you would need a hardened (and polished) steel "propeller" as my guess is that the thread would eat into plastic very quickly.
Any device like that would need to be extremely light-weight, particularly if the machine draws the thread in short, rapid bursts, or at a high speed, because anything that puts even a short duration tension on the yarn may cause it to break With a 300mm diameter cone of thread (nearly 12 inches in English measurements), the "propeller" would need to be either very large diameter, or mounted well above the thread at the feed-in point, and will have a risk of tangling if it free-wheels after the thread stops.
I don't really think a rotating device would be practical, but it depends on the machine - the description of this as a bobbin thread implies a sewing type machine, which would have a slower feed, but a machine with a rapid yarn feed will have the propeller rotating very rapidly as the diameter decreases.
@David18 No i dont have if i go there i will take a picture.yes it is a rapid taking yarn.Your idea true about it can tangling when yarn taking stops.and its a really problem.
Putting sensors to back side is better coparing the put sensors to front side, the best is putting middle of front side but this can be good too.How can we detect the movement here?
By the way i'm really appreciate for helping thank you both.
I obviously was not clear enough. I would like to see a brief video of the end of the machine that is pulling the thread.
If a "propeller" is not an option what about a little bar that sits on the thread near to the pulling end where I suspect the motion of the thread is smaller. If it had a little mass it might act as a useful damper. And if the thread was not being pulled it would stop jiggling or perhaps fall slightly.
I reckon you are going to have to experiment to find a suitable tell-tale. If you have a tell-tale then getting an Arduino to detect its motion would probably be straightforward.
Robin2:
I obviously was not clear enough. I would like to see a brief video of the end of the machine that is pulling the thread.
If a "propeller" is not an option what about a little bar that sits on the thread near to the pulling end where I suspect the motion of the thread is smaller. If it had a little mass it might act as a useful damper. And if the thread was not being pulled it would stop jiggling or perhaps fall slightly.
I reckon you are going to have to experiment to find a suitable tell-tale. If you have a tell-tale then getting an Arduino to detect its motion would probably be straightforward.
...R
Oh, i dont have the machine's video or picture and its far away from me.
i dont understand the "tell-tale" can you clarify please.
i checked the ultrasonic distance meter, and its not detect the thread i think the thread absorbing the sound because i make a ball of thread and it is not detecting it too.
@dougp thank you i checked their products but found nothing for me.
I will put a electret microphone above of bobbin housing so mic will be below of the bobbin and it will listen the yarn flows sound.And i will interrupt when arduino catch that sound.
Robin2:
It's going to be difficult to help without knowing what you are dealing with.
Any gadget that behaves differently whether the thread is running or not.
By the way, I don't think you have told us what might cause the thread to stop running.
...R
Thread is conneting to machine needle and machine is taking thread when it needs, like when machine starts knitting a "broken heart" its taking the red colored yarn and when done stops the red colored yarn and starts to pull black yarn for knit the broken section.
Robin i put my ear in the yarn bobin, it was quate soundless, and i started to pull yarn i heared it's sound.I think if my ear can detect the thread's sound an mini electret microphone will too.I will amplify the sound and detect the range of sound, and put an if condition in arduino program.What do you think about that?
As well as optical off the arm shown in your video, you could also consider hall effect switch with a magnet on the plastic arm, or, make the arm from steel, place a magneet on the back of the hall effect and it will detect the metal arm passing.
Of course one would need to fit some kind of bushing to the metal arm to protect the thread.
As far as any sound detector, machine shops are usually noisy environments and I don't think that approach would be reliable.
tlhsglm:
Thread is conneting to machine needle and machine is taking thread when it needs, like when machine starts knitting a "broken heart" its taking the red colored yarn and when done stops the red colored yarn and starts to pull black yarn for knit the broken section.
That brings up another problem, if you are going to detect yarn motion, you will need to know when each particular yarn is needed by the machine, otherwise you have no idea whether the yarn has stopped moving because it is broken, or because the machine simply isn't using it anymore.
There should be plenty of pre-existing sensors that are suitable for what you want, a quick search for yarn motion detector brings up plenty of examples, such as http://www.tecatron.com/textile-products.htm