Carding Machine - Velocity of the rollers

[tiamatjar]

Hello everyone, I am working in an Spinning Mill of natural fibers. As a project in this mill I have to improve the control of the carding machine.

A carding machine is the hearth of the spinning plant, it parallelize the fibers each other in order to form a nap or a sliver. This machine consist of a series of rollers depending the use-end of a yarn, this machine influence deeply in the quality of a sliver and after in the quality of a yarn. We have an old carding machine, it is quite big with of cops one more that a normal one, that brings us a good quality sliver.

In order to improve the quality of the carded fiber and the control of the machine, my mission is to develop a control of each roller or the most important called workers and strippers that sum in total 24 rollers. When I talk about a control is to know the velocity of the rollers during the running of the machine.
In simple words I am looking a sensor that could be able to installed near the roller, at a side of them and then see the velocity of the roller in a display screen. As a metaphor, it is like installing 24 tachometers in each roller and see them a display.

I have asked some type of sensor in some of our local electric/electronics suppliers and they do not have any answer. Regarding the display an the interface for the data is not a problem we have seen even arduino projects with something like data.

The problem lays to find a suitable sensor (tachometer sensor, or something like that) that could measure constantly the velocity of the roller during the running phase.

I hope somebody could helps or guide us. Maybe someone that had a similar problem.
I post a schematic photo of a carding machine.

Workers and stripper rollers are the ones up, on the the big cylinders.

Thank you for your support
Best regards,
Tiamat

 

[IRstuff]

Please refrain from double posting

Depends on the speed of the rollers and how much accuracy you need/want. Hall sensors, optical encoders, etc., etc., are all possibilities until you narrow the requirements.

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[EdStainless]

Originally wasn't this all gear driven? With fixed ratios between the various rolls?
How do you adjust the speed? How many independent speed adjustments are there?
I am thinking that you may not need to monitor each roll.

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[zeusfaber]

What IRStuff said - except not optical: Although you didn't said so, this is going to be a very dusty application.

A.

 

[waross]

I had a similar project in a printing house.
The customer wanted speed indication on a number of presses.
I used small toy permanent magnet DC motors as tachometers.
I used a voltmeter and a two series resistors to limit the current and to calibrate.
One fixed resistor in series with a potentiometer for fine adjustment.
The customer objected to the $1.49 toy motors.
I switched them out for $14.00 toy motors and he was happy.
The customer wanted an indication in Sheets Per Minute.
I had custom faceplates made for the voltmeters.

Bill
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"Why not the best?"
Jimmy Carter

 

[EdStainless]

You can even buy real DC tachogenerators that are calibrated to deliver a voltage (often either 10.00 or 20.00V/1000rpm).
Yes, I left the decimals out originally.
You can find small ones on the market for <$20USD each.
I used to have a box of USAF mil surplus ones.

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P.E. Metallurgy

 

[Bill West]

A little bit more about the rollers would help us see what needs to be sensed. Do the rollers have individual motors or are they on a common drive? If the latter why do you still get a speed variation between them? Are the rollers just driven by friction from the main drum? Is the gap/friction hand adjusted?

The ways to pick up a speed signal are optical, magnetic (Hall effect) or mechanical (tachometer generator)
The choices are influenced by:
-physical access to the shaft: a mechanical connection may require the most thought, magnetic or optical sensing of a target disk or gear teeth is easier
-accuracy: will seeing a difference of 2% over 2 seconds be fine or do you need to see that one roller has accelerated a quarter turn ahead in a fraction of a second? (I've read of the latter leaving marks in weaving fabrics)
-environment: dust, dirt, grease, water, heat or stray light in optical solutions. In an online picture I noticed a large amount of fluff around the machine, is it a fire hazard? Should the speed sensor be spark proof?

A few pictures of your machine and the roller ends would help a lot. I looked at the second picture here

http://www.customwoolenmills.com/carding

as an example of an old machine in Alberta. It showed a chain drive synchronizing the rollers.

Your application is interesting to look at but with the questions I've listed here I hope that Googling "industrial speed sensors" will bring up lots of suppliers and get you answers. Their websites and online literature will give guidance on choosing the best fit for your situation.

Bill