- This topic has 20 replies, 12 voices, and was last updated 10 years, 9 months ago by Anonymous.
March 25, 2010 at 1:41 am #40953Paul Fecteau
I’m building my first dual deploy rocket – a Wildman Dual Deploy with a 3 inch diameter avionics bay that has 2 all threads and centered eyebolts . I will be using dual altimeters for redundancy and this will require 2 ejection canisters and 2 screw terminals on each end cap as well. It will be a tight fit. I saw the SpaceTec canisters in Mark Canepa’s “Modern High Power Rocketry” book, but it appears they are no longer in business. Does anyone have an alternative suggestion?
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NAR – 88854 Level 2March 25, 2010 at 1:46 am #52295John A. WilkeParticipant
Get some LOC 1/2″ launch lug maaterial and cut it into various lengths. Then cut some 1/2″ dowel into thin strips (making itty bitty bulkheads). Epoxy the “bulkheads” into the end of the LOC tube.
After the epoxy is dry, drill through the wood to allow an ematch to pass. Stuff the other end with paper towel and use masking tape to seal ’em up. I’ve flown some of these 40 times. They work splendidly and are very reusable….March 25, 2010 at 3:26 am #52296greywolves
I was going to try using the surgical tubing method. Should i use a cannister or something more stiff to hold the tubbing, for more of a direction to the charge? any thoughts?
ThanksMarch 25, 2010 at 3:43 am #52297edwardModerator
Jon Skuba sells aluminum machined charge holders – might want to get in touch with him.
I just let the surgical tubing hang out in the rocket. Usually though it is packed tight against the bulkhead because the shockcord is crammed on top of it and it cannot move.March 25, 2010 at 5:55 am #52298MikeSModerator
3dogs suggestion works great.
I slide the canister into a 1/2 PVC coupler glued to the ebay with a
notch cut in the side for the wires. It holds it in place very well.
Last year I tried the surgical tube method on my 4″ and up rockets. I glue some velcro to the top of my ebay, I have some glued to the tube. it
stays in place well.
It being placed a top of the ebay gives it only two directions
to go,,,up and out.
Both ways have worked fantastic for me. Both learned from
NCR members who have used them for some time.
I still use my xmas bulb igniters in both.
Duel deploy is great fun. Good luck.March 25, 2010 at 12:41 pm #52299SCOTT EVANS
If your not going too high, fingers of a latex glove and pop ties work.
I have a rocket loaded and ready to go next launch with this.
Over 20,000! Ask the dog guy!
I have used pvc caps too.
Lots of didderant ways!March 25, 2010 at 1:54 pm #52300Warren B. MusselmanModerator
After the UprOar Project (see photo gallery) and a number of other rockets since then, I’m 100% committed to using the surgical tubing method. Cheap, disposable and VERY reliable if you use quality zip ties to seal the ends.
WarrenMarch 25, 2010 at 3:21 pm #52301Steve JensenParticipant
Thanks Warren, it appears to be a solid technique.
Does it take any additional BP to overcome the tubing package?
I have a 54mm bird and I’ve calculated I need about .5g of powder to get it out. (I am ground testing!)
I also notice that people put two ties per end of the tube unit. Is this your technique?March 25, 2010 at 5:34 pm #52302John A. WilkeParticipant
go here http://www.wimpyrockets.com/page16.html and always ground test…March 25, 2010 at 8:33 pm #52303Steve JensenParticipant
Seems like ground testing is mandatory.
So, I take it you had a lengthy set of wires from the alt-bay that let you feed the surgical tubing charge bundle in amongst the folds of your drogue section shock cord? (I know you don’t use an actual drogue)
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