Thread: Pop Lugs
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Old 05-22-2017, 10:48 AM
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chanstevens chanstevens is offline
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Join Date: Jan 2007
Location: Cincinnati OH
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Quote:
Originally Posted by Tango Juliet
Actually I was referring to the fit of the old CMR type of Pop Lug to the rocket using the wire pins/loops.


In that case, then "snugness" is not really supposed to be an issue. The angle of the forward bend in the pop lug that holds it in place determines how sloppy or loose the fit is and how easily it separates when it hits the tape at the end of the rod. At the extreme, for example, if it were a 90-degree bend and its length exactly equaled the tube thickness, it would be a very tight fit but never come off. If it were more like 30 degrees and spanned more than the tube thickness it would be loose and sloppy, but come off very easily.

I believe the right balance and middle ground is for the angle to be about 45 degrees, but most critically the span should be very close to the wall thickness, maybe no more than 1/16" greater. The key is for there to be two parallel legs on the lug that are basically just a hair more than the wall thickness apart, separated by the angled bend. The angled bend is just supposed to "nudge" the lug away from the body when the lug it's attached to strikes the tape and starts to slide back along the body.
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