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Ejection wells

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ericm541

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Has anyone used G-10 to make ejection wells? I'm at that point in my current project and i was just going to use the PVC caps i usually use. Mcmaster carr has a variety of G-10 including solid round,would be easy to drill and shape, i could buy the aluminum ones Mac performance has. wheres the fun in that :).





Eric M
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rharshberger

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Has anyone used G-10 to make ejection wells? I'm at that point in my current project and i was just going to use the PVC caps i usually use. Mcmaster carr has a variety of G-10 including solid round,would be easy to drill and shape, i could buy the aluminum ones Mac performance has. wheres the fun in that :).





Eric M
NAR 85115
Watch out for pultruded FG solid rounds they dont take pressure well, and can splinter upon ejection charge firing. I used some 1" diameter pultruded FG solids drilled with a .5" diameter hole and the blew apart on my L3 projects shakedown flight. Filament wound probably would have worked much better.
 

Bat-mite

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Dog House wells at Binder Design are a great option. Several sizes.
 

ericm541

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Rich, I read your cherokee-D L3 build, gotta say nice work great planning. What dimensions are those aluminum wells, they look custom made.

Eric M
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rharshberger

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Rich, I read your cherokee-D L3 build, gotta say nice work great planning. What dimensions are those aluminum wells, they look custom made.

Eric M
NAR 85115
Thank you, the wells are custom made by a local-ish friend of mine (he lives in Seattle area), the wells are 2.75" tall, ~1.0" diameter and the wall thickness is .125". The wells are sized to accept a 6ml Centrifuge tube, and they are drilled at the base to pass the wire out, they are also drilled for a #8 machine screw to fasten them to the bulkhead.

Below is a picture of the original shakedown flight charge wells, aka "bad idea #1", they blew apart lengthwise, evidently I was too embarrassed to take a picture of the failure. The wells were made from electrical grade extruded aka "pultruded" solid round. The largest charge was 4.5grams of BP. The longer/deeper a charge well is the stronger the material it needs to be built from, but the gain is hopefully more complete BP combustion and more gas production.

bad idea.jpg
 
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Handeman

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I still like the copper pipe caps for capping copper water pipes. 1/2" will take about 4 cc while the 3/4" will take 6cc (3 centrifugal tubes). 1" and larger sizes available. They are not tall and thin, but they are cheap. Check Home Depot or Lowes. Just drill a hole and use a SST screw to attach to the bulkhead. They will be discolored after the first use, but I have one rocket that has 45 flight and they still work fine.
 

DavidMcCann

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I got these from MAC. Not terribly expensive, and not really a place I'm looking to save pennies. I've used a variety of other options, and this is my favorite thing now.

 
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