I have never seen them used in person that Im aware of. I dont think even on some L3 rockets. Id suspect there is a starting chute size at which it becomes important.
Pretty simple. This is my way; others will vary. There is a loop on the top of the bag. Attach the pilot chute to that. Put a Nomex under it. Inside the bag there is a long tether. Attach that to the top of your main chute. Pilot chute pulls bag off of main chute, remains attached by the tether. Z-fold and stuff shroud lines in any orderly fashion under the elastic bands.
Main chute shroud lines attach to the nose cone. When the NC and D-bag come out of the payload tube, the NC starts falling down, but the pilot chute pulls the D-bag up. Shroud lines get systematically yanked out of the elastic, and the the chute falls out of the bag.
Final picture below:
View attachment 335973
To supplement John's answer.
[video=youtube;YvzI5QJftjI]https://www.youtube.com/watch?v=YvzI5QJftjI[/video]
[video=youtube;_0YHlspcqeU]https://www.youtube.com/watch?v=_0YHlspcqeU[/video]
[video=youtube;wGLu54LYfbo]https://www.youtube.com/watch?v=wGLu54LYfbo[/video]
And there are more on YouTube
I can mock up my Darkstar and take some pics for you
Sent from my ONEPLUS A3000 using Rocketry Forum mobile app
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I also used my 4" Tomach, in my avatar, to experiment with a deployment bag but this was using a custom deployment bag holder against the bulkhead of the nosecone
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Not going to ask you to do that. A drawing similar to John's would do it, but before ejection.
You sure that's not a Tembo? :wink: Sorry... couldn't help myself.
I really am following along trying to learn, not just here to bust your... well, you know. Been considering D-Bags for a while now. Pat at Dino Chutes has em for 2.5" and 3" rockets, which I have been wanting to try, just haven't yet.
The bag opening faces the bottom of the rocket. Think of it as the bag being pulled off the chute - the chute is anchored to the body tube and the bag is anchored to the nose cone. The nose cone/drogue chute pull the lines out of the loops and off the parachute, so the bag opening should be facing the airframe.Thank Michael, knock yourself out!
It's looking more and more like my question about the configuration in the tube boils down to which direction the bag opening faces. Extremely basic but I would think very important! Yet no one has even mentioned that.
It makes sense to face the opening down as long as a strap connects to the cute at the spill hole to the bag which in turn is attached to the pilot. For those that "free-bag", it would appear that setup is less dependable about getting the chute out.
Quite the opposite, iirc the free-bag method is the least prone to tangling of the d-bag systems. ... Its possible for the bag to be stripped off the chute...
If tangling is a much bigger concern than leaving the cute in the airframe then maybe, but that's not what I was talking about. The free-bag system may be less likely to tangle after deployment, but since the main chute is not attached to the pilot (via the bag) there is more chance you never get the main into the airstream, correct? With the Main attached to the pilot there is always a chance a "stuck" main, for whatever reason, could be pulled free before is goes splat , right?
If I have to choose between a fouled/tangled main over a no main at all it seems most cautious to choose the prior. That's all I'm saying.
From all the research I did the true free bag method - where the d-bag is attached to the nosecone and recovers separately - is the most reliable method
I put together a thread that will hopefully provide you more insight and become a source for answering all questions on using deployment bags.
https://www.rocketryforum.com/showthread.php?144212-Demystifying-Deployment-Bags
I put together a thread that will hopefully provide you more insight and become a source for answering all questions on using deployment bags.
https://www.rocketryforum.com/showthread.php?144212-Demystifying-Deployment-Bags
The way I tested my setup was to pack everything in the body tube as I would for a flight. Then I had someone hold the tube while I grabbed the nosecone and took off running (well, maybe not running but moving at good clip). The tube was on a stand about a foot and a half off the ground. I could see how things were pulled out of the body tube and how they stretched out on the ground and finally how the d-bag was pulled off the chute.I asked a question on that thread.
https://www.rocketryforum.com/showt...tifying-Deployment-Bags&p=1756998#post1756998
The method uses ... Two harnesses come from the piston. One goes to the cone and the other to the deployment bag and pilot. Upon deployment, both harnesses get stretched out to their length, but then the cone goes down and the bag/pilot go up.
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