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I just got a new tensioner. The Azonic with the pulley that is supposed to measure grams of tension. Luckily I know by feel and appearance as to what tension I like to use but I was hoping that this tensioner would provide more accurate results. I like it but the arm bounces up and down so I can't really tell the tension. Plus I have back tension before the wire ever goes through the tensioner. It bounces around 10 grams but I know it is more than that. I am sure that I am putting around 30 grams but I can't accurately measure this. Does anyone know of a device that will accurately tell me the tension I am using?
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I doubt that you're going to find anything commercially available (for any reasonable price) that will measure tension in thin magnet wire. In most commercial applications where they would want to accurately control tension, the function would be designed into the production machine. Generally, the important thing is to measure/control the tension right as the thread/wire enters the part. So, the function needs to be built right into the feed mechanism.
It's probably easier to build your own mechanism. The principle is simple enough. In the space between the bobbin and the tensioner (the friction device that creates the drag on the wire), the wire has to make a 180 degree turn around a pulley. That pulley is mounted to a pivoting arm, which has a force applied to it by either a weight or a spring.
In a balance-type mechanism, you'd hang a small weight on the end of the arm, which would represent the amount of tension that you wanted to apply. You'd start the machine and increase the drag on the wire until the weight just lifted off the ground.
In a spring-indicator mechanism, a spring pulls on the arm and a pointer attached to the arm moves along a scale to read out the tension. But you have to calibrate it first to know where to put the lines on the scale. This is usually done by hanging little weights on the arm (10 grams, 20 grams, 30 grams, etc.) and drawing the lines.
That's about it. You have to do the math on the geometry of the layout that you choose, but it's not hard. -
Be careful. The velocity of the wire varies by 3:1 to 5:1 because the bobbin is oblong, and the resulting pulsations (two pulses per rotation) are hard for a tension meter to follow, and if there is too much inertia in the dancer, the wire will break.
A music-wire fishpole dancer between tensioner and bobbin may help.Comment
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You will probably find that the spring tensioner part that reads the grams scale will bob around too fast and break the wire at winding speeds. The guage is pretty much useless, most pickup makers who use that tensioner run the wire without using that pulley at all. Set your tension by feel then wind. I had one but sent it back, because at the speeds I wind at which isn't that high it always broke the wire. It is useful though if you bypass the gauge. You can guess the tension by using the gauge and where the middle of the bouncing motion is, will be what your tension is, then remove the wire from that pulley and wind. Problem is though that over time the tension may change due to wear on the tensioner parts. TV Jones uses those the way I described. I just use thumbscrew and felt and go totally by feel....http://www.SDpickups.com
Stephens Design PickupsComment
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Possum, I thought you were tensioning the wire between your butt cheeks while ageing covers in your underwear. Why the change to felt?sigpic Dyed in the woolComment
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I've switched to your method of running the wire between sheep's balls, the lanolin is a natural lubricant for the wire and imparts a sheepish tone. The sheep doesn't like it but given enough oats they don't complain; I have to rotate sheep so the burn marks heal.
No, I've switched to aging humbuckers in the cesspool out back, 2 weeks submerged and they come out looking great, the smell doesn't bother me much but customers keep sending them back, I just send them a bottle of perfume with the pickups if they don't like the authentic bar room toilet smell...http://www.SDpickups.com
Stephens Design PickupsComment
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I think that "CessBuckers" is a brand waiting to happen.Comment
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Hey thats a good idea, I tried to trademark "ShitBuckers" but the patent office guys said no, maybe they think buckers is a dirty word....http://www.SDpickups.com
Stephens Design PickupsComment
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I got a quote for one of these once (a few months ago) with a digital readout and they were around $1000 with the readout/controller that had an output that you could send to your PLC to stop the winder if the tension spiked or started getting too high (Probably to late to stop the wire from breaking!)
Here is the site: Tension Meters
They gladly sent me CAD too so that I could import it into my winder CAD file that I was designing (Wishful thinking...someday)
I'm not even sure how good it would work on oblong bobbins like pickups where the wire velocity is constantly changing. Of course this is probably way overkill and I am getting by just fine right now without it, but it sure would be cool to have one to try out!Comment
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to measure tension we could try to built a tool similar to that.... 2 fixed pulley and the center one on a spring.... in the spring we also put a small magnet and near it (but fixed) a hall sensor.............my gaussmeter project..... ........
.......first pickup with my cnc winder........
.... NEW cnc pickup winder user manual.....Comment
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Just from the size of the pulleys, I would expect wire breakage unless there were a fishpole dancer between bobbin and tension guage. The fishpole dancer, made of music wire, smooths the pulsations out.Originally posted by Chadheckler1 View PostI got a quote for one of these once (a few months ago) with a digital readout and they were around $1000 with the readout/controller that had an output that you could send to your PLC to stop the winder if the tension spiked or started getting too high (Probably to late to stop the wire from breaking!)
Here is the site: Tension Meters
I'm not even sure how good it would work on oblong bobbins like pickups where the wire velocity is constantly changing. Of course this is probably way overkill and I am getting by just fine right now without it, but it sure would be cool to have one to try out!Comment
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You have a picture? I have not used one before...Originally posted by Joe Gwinn View Post
Thanks,
ChadComment
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I don't have a picture. But it isn't necessary. Take a piece of music wire perhaps a foot long and make a helical loop in one end, and clamp the other end to something solid. (To form the loop, heat the end of the wire red hot and allow it to cool slowly. This will anneal it, allowing you to form it into a small helix.)Originally posted by Chadheckler1 View Post
Then arrange things so the wire changes direction when it goes through the helical loop, and the wire tension pulls the wire into an arc. It looks just like a fishpole.
In operation, the bobbin rotates and periodically jerks the wire faster then slower, the helical end of the wire bobs up and down, smoothing out the pulsations. The bobbing looks like a fishpole when one is fighting with a doomed fish.
The reason to use a foot of music wire is to allow the end to bob up and down an inch or two without overstressing the wire.Comment
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