L3 Project Construction Tips

[Bruce R. Schaefer]

You would be surprised how much 1 gram can do when topping it on to what exist.

Oh yeah, VERY GOOD POINT! Tell you what, I’ll add a half a gram to each redundant charge, meet ya half way. I KNOW that much will only add an extra precautionary push without doing any damage.

[Conway StevensParticipant]

your chances for damage are pretty slim as that its a Glass rocket and Convolute at that. I can tell you that the tubing you are using will handle a 12 gram charge or better no problem. I tested mine to 12 grams. same tubing. But that should be fine what you are doing.. so do I still get to sign ya off? lol

[Bruce R. Schaefer]

But that should be fine what you are doing.. so do I still get to sign ya off? lol

That’s up to you. Ha! After getting a night’s sleep, bumping each redundant charge up 1/2 gram will be a little added protection. The thing that keeps going around in my mind is that 1 extra gram blew the booster up on my last rocket, since fixed, and WASN’T a G10 airframe. I know the airframe will handle it, and the harness is strong. It’s a pretty large gray area that works as far as how big the charge can be, I just don’t want to go outside that gray area on either side. It’ll work.

[Bret PackardParticipant]

Bruce, you’ve done a spectacular job on that rocket. I can’t wait to see it fly. With all the thought and experience that you’ve put into it, as well as the support you’ve gotten from other club members, I’m sure you’ve maximized your chances for success. It’ll be awesome.

[Bruce R. Schaefer]

as well as the support you’ve gotten from other club members, I’m sure you’ve maximized your chances for success.

You hit the nail on the head there, Batman. No one does it alone, and I’ve gotten support from the best.

[James Russell]

with your ground tests I feel comfortable with how ever you go as long as you are not going down…fast I mean:) you have put a lot of thought and taken a lot of input from others and I fell you are going to make the right decision. I would go with the “blow it apart or blow it up” mentality on the remote charges because there will be no damage to the rocket if all is out and it it is not out you better make sure it does get out:)

JamesR
your L3CC

[Bruce R. Schaefer]

I would go with the “blow it apart or blow it up” mentality on the remote charges because there will be no damage to the rocket if all is out and it it is not out you better make sure it does get out:)

JamesR
your L3CC

Got it.

[Doug GerrardParticipant]

I would go with the “blow it apart or blow it up” mentality on the remote charges because there will be no damage to the rocket if all is out and if it is not out you better make sure it does get out

I agree. On the maiden flight of Freeze Frame I had tested the amount of charge on the ground for apogee and decided to use the same quantity as the back-up. I figured the first charge would at least shear the pins and in case it didn’t completely separate the back-up would push it apart. Wrong, both charges went, shear pins sheared and it still stayed together. Fortunately the nose separated at apogee so the main deployed then. I guess this was a case of two failures make a(n apparent) success. Next time I’m going with 6-32 shear pins for the nose cone and double the charges at apogee…

Doug

[Bruce R. Schaefer]

I figured the first charge would at least shear the pins and in case it didn’t completely separate the back-up would push it apart. Wrong, both charges went, shear pins sheared and it still stayed together. Fortunately the nose separated at apogee so the main deployed then.

See, simultaneous ignition of charges can occur, though rare. IF that happens with my L3 attempt, the rocket will stay together. Doug, I’m using the blacksky as my primary electronics, and I’ve only flown them once, and they worked fine.

Next time I’m going with 6-32 shear pins for the nose cone and double the charges at apogee…

Glad you said that, that’s what I’m using for the nosecone and main. And, I’m going to go the Con way and add a gram to each redundant charge. Booster 4-5 grams, and main 6-7 grams. Because I’m using the WRC2, the only way I’ll have both charges going off is if I panic and push a button at the wrong time.

[James Russell]

are you using only 2 charges and a match for each and then another mach to the same charges from the WRC or do you have a charge just for the WRC? I was under the impression you had 3 charges.

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