High altitude

[SCOTT EVANS]

At what point do you have to start to worry about powder ignighting properly for ejection? Feel free to chime in John! Mr altidude. 8)
Off hand how high are the RRC2 minis good for.
Maybe theres another I should use.
My next shot will be about 17000 or 18000 with the M795 with my Little Brother.
After that, we may try the booster on the bottom in the Spring. 8)
Moooooooooon Burner x2 😀

[James Russell]

RRC2 Mini is a 40k if I recall.

Most people will say 20k-30k is were you start to see real problems with BP and you need to start taking extra care in making your charges. Really as you go up it changes so the higher you go the more BP you may need but it will also depend on your type of charge. If you are packing your charge in surgical tubing, that seem to have the fewest issues for high altitude recovery but some people use PVC and other things, you just need to pack them tighter so that they stay together as the BP burns to insure it all burns to get the needed pressure to get your deployment. It is also a good idea to add more to the apogee charge to help with the same problem but that is based on experience and refined skills do to the variations in techniques and consistency in building charges. It also has a lot to do with what materials are used in construction to also determine the extra measure you use. FWFG tubing can take a lot more then paper or phenolic.

I will add that most of the guys flying over 15k-20k are using the surgical tubing and a lot of people are using it for all flights…

[edwardModerator]

Since I’ve discovered the surgical tubing I’ve been using it exclusively. So easy to make the charges and they are in nice neat containers. For my 2 L3 attempts I’ve used them – worked great at 20k and 25k to deploy the laundry.

Edward

[Steve JensenParticipant]

Are there different types (diameters/wall thicknesses)?

Thanks!

[edwardModerator]

Yes, there are. I generally use 1/2″ with 1/16 walls, and have gone up to 5/8 with 1/16″ walls.

Edward

[AdrianParticipant]

About a year ago I got some thick-walled tubing from McMaster and the ID was too small to get enough powder in there. Then a few days ago I bought some tubingg that Home Depot sells, thinner-walled stuff that has worked well in ground tests so far with Pyrodex. It’s not quite as compact as potting the charges into cardboard tubes with epoxy, which is what I do for my usual tight volume applications, but it is easier.

[Doug GerrardParticipant]

I prefer the thicker walled surgical tubing. My way of thinking, the higher the bursting pressure, the longer is had (and higher pressure) to completely burn the powder. I get mine from McMaster and I typically use 3/8″ ID 1/8″ wall for charges of about 4 grams and 1/2″ ID and 1/8″ WT for up to 8 gram charges. Of course I use a plug at each end instead of just tying them off closed. Plus, I’ve gone away from the zip ties and use hose clamps. They’re cheap and crimp on easier. Hope this helps,

Doug

[Warren B. MusselmanModerator]

I’ve switched over completely to the gum rubber hose method for charges. I have been using wire ties, but I like Doug Gerard’s idea of hose clamps even better. I haven’t flow anything else in 3 years now.

Warren

[Ed Dawson]

I just don’t want to get hit by one of your hose clamps falling from 10,000 feet.

I’ll stick with zip ties.

[Doug GerrardParticipant]

I just don’t want to get hit by one of your hose clamps falling from 10,000 feet.

I’ll be more worried about being hit by the rocket attached to the surgical tubing that was sealed with a tie wrap that gave way than a hose clamp. Haven’t you seen the Mythbusters show on the falling penny? Terminal velocity would prevent any significant damage from being done from a hose clamp.

Doug

[Author]

Posts