弯有效圈
把3/8"铜管弯成紧密的螺旋线不是一件容易的事，它不光需要招数，还需要手艺，在此我来展现我的技艺。招数就是往管子里填干砂，填完后震实，封死端部，就可弯成任何直径。
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往下看我的手艺
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The jig consists of only 2 pieces. An axle, called the mandrel, that sets the coil's inside diameter and the combination bearing and work rest/guide. For the coil at hand, I used a 1" machine shaft and a 1" rigid coupling, both obtained from McMaster-Carr. I don't happen to have a vice at the moment (can you imagine a nerd without a vice?) so I welded the coupling to a piece of plate and clamped it to the bed of my medium duty box van using C-clamps.
A small length of bolt comprises the work rest. Another piece is welded to the axle to form the retainer. The part of the work rest that contacts the tubing is contoured to fit the diameter of the tubing using a Dremel tool.
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This shows another view of the mandrel and work rest
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Yet another view.
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Here the tubing is positioned to start the bend. It greatly helps to put a little moly-loaded grease on the tubing and the rest/guide. Be sure to leave plenty of excess tubing at the start so that you will have the leverage necessary to bend the end to shape to fit the capacitor
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The first turn is made. This is the hardest. The mandrel is being turned with a pipe wrench. A handle was not welded on because the axle has to slide out of the bearing to remove it from the finished coil. Someone with a mill-drill or milling machine could come up with a much better crank but for me the pipe wrench worked fine.
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Several turns have been wound here. You'll notice a couple of things. One, I cut the head off the bolt that formed the rest/guide. Too much friction. The result of too much friction is the denting of the tubing under the mandrel piece. A well lubricated bearing and well lubed tubing require little effort to bend. An almost mirror finish on the part of the rest/guide that contacts the tubing helps a lot.
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Winding is complete.
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The capacitor is held up to the coil to assist with bending the coil leads. Beneath the coil is visible an early version of a Litz coil that I wound from enamel coated motor winding wire. It proved the efficacy of Litz wire and demonstrated that I ought to get some real manufactured wire.
The major advantages of the copper tubing coil is that it can be made with hardware store materials and it can be water or air cooled. These benefits outweigh the added efficiency that the Litz wire provides.
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发表于 2013-2-27 16:26:46
|Archiver|手机版|小黑屋|热处理之家
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发表于 2013-2-27 17:33:23
发表于 2013-2-27 19:49:38
