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In article .com,
K7ITM wrote: Good point about other tooling methods (laser cutting not the only one available), but the question remains, how many people would actually be interested in buying plates, at what cost levels? (At the time I was making the other parts, soft tooling was cheaper for very short runs, but the shop that did the punch/die was set up to make such tools at very low cost and easily beat the soft tooling for modest runs. You just need to decide how many of your parts you want, and go shopping.) At the price you suggested (a couple of dollars per plate), the cost of putting together a good-sized air variable is going to be fairly fierce. It may be somewhat less than the cost of a new, commercially manufactured AVC, but it's probably not competitive with the cost of used-but-serviceable air variables at hamfest/fleamarket prices. You might find that it was appealing only to those who needed a fairly specific size/capacitance/standoff-voltage combination, not available used. You might find it attractive to specialize a bit. One not-uncommon application for large air variable caps these days, is people who want to make a magnetic-loop transmitting antenna. In this application, keeping resistive losses in the cap to a minimum is very desirable to help keep the Q and efficiency as not-terribly-low as possible. One way to do this is to use a welded rotor/shaft assembly, and welded stator plates, to reduce resistive losses. This is beyond the capabilities of most homebrewers, I think. An alternative is to use a soldered construction, which can't be done easily with aluminum but which is relatively easy if your shaft and spacers are brass, and the plates are either brass, or PC-board material (double-sided would work best). Hence, you might increase the demand for such stamped or laser-cut plates if you were able to offer them in materials other than aluminum. The materials cost for brass would probably be higher than for aluminum, but you might be able to offer plates in double-sided FR4 for prices no more than aluminum. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
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