Controlling wire tension in a coil winder

Danko

Joined Nov 22, 2017
1,134

MisterBill2

Joined Jan 23, 2018
9,293
Power supply noise can certainly be a problem in many systems, that is true. Your solution seems reasonable, it may be that you have had to deal with more power line noise that I have. Of course, many of our machines included Sola constant voltage transformers, which do tend to reduce several types of noise. For some factories we used them for every machine that had any digital or analog control systems.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
7,411
Only way I see, to place controller and SPS in fully closed metal box and use common choke filter:
View attachment 182925
https://eu.mouser.com/ProductDetail/EPCOS-TDK/B82732R2102B030?qs=x3Z3TaiycdstnTWZCCNihg==
Hello again, Danko my friend. It's always great to hear from you.

Thanks for the suggestion. The wall wart (which is an SPS) already has a small common mode choke in it. And I doubt (though I might be wrong) that EMI in the form of radio emissions is a problem, since no nearby devices of any kind are affected, other than the controller itself. Something tells me that the problem lied in electrical noise traveling back through the wires, and that was causing glitches at the SPS, which in turn caused spurious resets of the MCUs. The machine has had an EMI filter installed in it from the very beginning, but it seems that it wasn't enough. It was only when I installed the diode and LC filter shown in my previous post that things were completely solved.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
7,411
Interesting indeed. I have programmed and created the connection arrangements for machines that check electrical harness installations but I never gave a thought to how the harness assemblies were made. To keep up with the production rate of a car per minute it must take a lot of harness builders, even if they are robots.
There are barely any robots involved in the manufacturing of automotive harnesses. The only automated machinery involved is dedicated to installing and crimping terminals and their sockets/jackets, and then cut the wire to length. The assembly of the harness itself is entirely manual, and the way I see it, it will remain that way for several decades more because the job itself is far too complex for a robot to perform. Electrical harness factories employ thousands and thousands of people, and are normally located in developing countries where labor is cheaper.
 

MaxHeadRoom

Joined Jul 18, 2013
23,634
I use a CNC controller of my own design ... it's completely built using the 8051 architecture, and works with a 10-bit speed resolution, which I've found to be enough for the kind of projects I've been involved with. And the good thing is that the system is address-based for each axis, and so can do simultaneous interpolation of up to 255 axes. Although it is not yet capable of performing routing operations ... but I'm currently working on it :cool:

The entire project's firmware is written in assembly, and its software in .NET. I'm using the MCP2221A chip to communicate to the computer through a virtual COM using a USB port.
Quite the achievement, I used the Galil Motion servo cards in the past, great for PC based DIY systems, they have features such as electronic gearing for up to 8 axis if needed.
And simple to use DC and BLDC motors and drivers.
My main occupation was CNC retro-fitting using Fanuc and Mitsubishi et-al.
Max.
 

MaxHeadRoom

Joined Jul 18, 2013
23,634
There are barely any robots involved in the manufacturing of automotive harnesses. The only automated machinery involved is dedicated to installing and crimping terminals and their sockets/jackets, and then cut the wire to length. The assembly of the harness itself is entirely manual, and the way I see it, it will remain that way for several decades more because the job itself is far too complex for a robot to perform. Electrical harness factories employ thousands and thousands of people, and are normally located in developing countries where labor is cheaper.
I did quite a bit of CNC machine maintenance for a Bus manufacturing Co. and the only automated machine they used in the wire looms was the wire measuring, stripping and cut to length.
Max.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
7,411
Most of EMI are produced by PWM of split capacitor motor.
In post #52 I placed link to SPWM module, for AC motor controlling.
EMI from SPWM can be easily eliminated.

View attachment 182935
I think I remember that post. But wouldn't additional circuitry be needed to drive the motor? Like power transistors and a filtered HV DC power supply? On the other hand, is it better to drive a split capacitor motor varying its frequency instead of its mean voltage?
 

Thread Starter

cmartinez

Joined Jan 17, 2007
7,411
Seems so, in addition there should be diode bridge and capacitor for HV from power line.
And, this module can control not only frequency, but also amplitude!
View attachment 182943
So, with that sort of module it's possible to build a VFD! ... a little too complicated for this project, but I'll definitely keep it in mind for future applications. I wonder how much more circuitry is need to configure it as a vector drive.
 

MisterBill2

Joined Jan 23, 2018
9,293
There are barely any robots involved in the manufacturing of automotive harnesses. The only automated machinery involved is dedicated to installing and crimping terminals and their sockets/jackets, and then cut the wire to length. The assembly of the harness itself is entirely manual, and the way I see it, it will remain that way for several decades more because the job itself is far too complex for a robot to perform. Electrical harness factories employ thousands and thousands of people, and are normally located in developing countries where labor is cheaper.
I had guessed that, given that I have had to design rather simple cables and harnesses. Especially for autos, which have so many different types of connectors on every harness, it would be interesting to see if it even could be done by a robot. But for starters, getting the pin into the right position in a connector would be a major task, and then inserting it correctly would be another big task. But the benefits from having a robot do it right would be big. Probably what would work well would be a team of robot and human, where the robot could run the wire and the human insert it in the connector.
 

shortbus

Joined Sep 30, 2009
8,814
But for starters, getting the pin into the right position in a connector would be a major task, and then inserting it correctly would be another big task.
Having worked where they made the harnesses( connector bodies,wire and terminals) most modern connectors are what is called, "pull to seat". The wire gets put through the connector then stripped and terminated the pulled back into the connector.
 

shortbus

Joined Sep 30, 2009
8,814
The only automated machinery involved is dedicated to installing and crimping terminals and their sockets/jackets, and then cut the wire to length.
The old ones GM Packard used were actually originally shoe lace cutting machines, made by a company they bought out, Artos Cutter. Artos is still making wire cutting machines.
 

Wolframore

Joined Jan 21, 2019
2,342
Yeah ... as I said, it's a very manual process, it's practically a craft:

Wow that reminds me of a job I had when I worked with arcade games. All those folks making and putting in those harnesses. Quite a process. I felt bad ass having to just spot check their work. I was only responsible for artwork at the time but we all had to take turns making sure things were going well and on time.
 
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MisterBill2

Joined Jan 23, 2018
9,293
Wow that reminds me of a job I had when I worked with arcade games. All those folks making and putting in those harnesses. Quite a process. I felt bad ass having to just spot check their work. I was only responsible for artwork at the time but we all had to take turns making sure things were going well and on time.
PC board artwork is a HUGE responsibility, it has the ability to really mess things up and waste lots of resources if it is done incorrectly.
 
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