Dark Shadow Parachute Deployment Mechanism
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- Опубликовано: 14 июл 2024
- A detailed description of the Dark Shadow parachute deployment mechanism and its payload.
For more details please visit:
www.AirCommandRockets.com/dark...
Dark Shadow build log:
www.AirCommandRockets.com/dark... 
Наука
This is a fantastic insight into the design of this rocket's payload sections. I'm going to have to watch it a few more times to truly appreciate just how good your design is and how it all fits and works together. Thanks for posting this video. Cheers, b.
This is done with lot of love, care and ingeniosity. Great job bro !.
The sophisticated design is impressive! Just an industrial design;)
A well thought out and made design
Beautiful engineering!
he mechanism looks very nice and I love how it is designed and built. Well done George !
Florin O Thank you Florin. :)
Great job! You earned a sub!
Just wanted to say, I'm Aussie too!
Cool deployment system!
Thanks for sharing this video i see some very good improvements! The finish product looks very good and very well made.
Basrockets Thanks Basrockets. There is still a little more improvement we can make in making the grapple arms lighter. We weren't sure how they would handle the acceleration forces and then getting bumped around on the way down and when landing so we decided to sacrifice some weight for strength in these tests.
Very wonderfull rocket ! Is flying fun with water
what's the material that you used for the body and cone?
Simply Genius! A suitably sophisticated system for a such a unique Rocket. What is your design process? Have you experiment with other systems? Have you considered using a modified 'High G' Side Deployment Mechanism?
That is a wacky technique for creating the PET plastic sheve. Must have taken some patience! Cheers, Jamie B.
JSB Rocketry Thanks Jamie. We spent quite a bit of time thinking about this one to overcome some of the problems we had with the Shadow's deployment mechanism. One was getting the shock cord attached to the pressure chamber rather than the payload bay. With the piston we had on Shadow the shock cord would have needed to go past it and the high forces on the shock cord would have bent the piston. The other consideration was the friction needed on Shadow to hold the nosecone in place. This was always a little touch and go. If too loose it could drag separate and if too tight the piston needed a stronger spring to make sure it had enough force to overcome the friction. The friction changes based on temperature and humidity so it was always a little iffy. With this design the friction is taken out of the picture. Wanting the system as compact as possible meant that we didn't have space for a piston anyway and why we went with the rubber bands. The grapple arms were designed because the rubber bands pull rather than push like a piston. The rest of the layout was based on making the whole thing withstand the expected G forces.
The pockets for the electronics was my wife's idea, I decided to make them out of PET. It took a couple of go's to get them right. :)
As always amazing work, George. :)
The precision and quality of your rockets is absolutely outstanding.
It's interesting to see that you switched back to a time controlled System because you don't want to activate the system accidently. I guess you would prefer the g-switch otherwise. ;) What is more reliable in your opinion, a time based system or a g-switch based system? As you may know we still use Tommy Timers because we really like the reliability of them as well as their durability.
Cheers
Julian
RaketfuedRockets Hi Julian, the G-switch is only used for detecting launch and not detecting apogee. We have always used a timer for deployment. Because we weren't sure if a tall enough ladder would be available at this launch to go up and arm this rocket, we had to bring it down in order to arm it. If we armed it and then bumped the rocket enough putting it back on the pad then it may have triggered the timer. The break-wire made sure we could handle it as much as we liked without it triggering. This turned out to be a good decision as the ladder we borrowed at the launch just wasn't tall enough.
AirCommandRockets
Interesting, I didn't know that.
We also thought about a sort of break wire and an electrical parachute system, but we wanted to place the "break wire" at the nozzle, so that the gardena coupling would close the electric circuit. However, our planned timer used a relay and we were worried that this component would be damaged by the acceleration of the rocket. We have to reconsider such a system and we'll try to solve the problem with the relay.
RaketfuedRockets One thing to watch out for when running wires the full length of the rocket is you have to take into account the stretch in the rocket. A rocket can stretch 1-2cm when pressurised and if your wire connections are tight between top and bottom you could potentially pull wires out of sockets. Ideally though you can just have a trigger inside the nosecone for your relay without a need to run anything to the launcher.
AirCommandRockets
Thank you for the tip!
Our latest rockets are reinforced, so I think the stretching effect is almost not noticeable. Maybe we'll attach the break wire on the guide rail, this would solve the problem.
+AirComket透かしs 顔危惧ゲームエクササイズｅｇ．みたいな
Can you please specify the type of camera you're using and is it sending ground images live ?.
Thank you.
It'a a keychain 808 #16 camera V3 (wide angle lens) - No it only records to the on-board SD card. www.ebay.com.au/itm/Mini-DVR-808-16-V3-Lens-D-Car-Key-Chain-Micro-Camera-HD-720P-Pocket-Camcorder-/180937263580
Hi, what kind camera type are you using on rockets ?
Andrey Gilenko Hi Andrey, We use the 808 #16 V3 HD camera from ebay. It is the one with the wide angle lens.
As a teacher I have been doing quite a few water rockets as school projects, but always just a 1,5L bottle and a Gardena based launchpad. No altimeter and no parachute. Its time to turn it up a notch. I was wondering why you use time for the parachute. I see the comments about g censor, but why not have it peek altitude trigger it? You log the altitude anyways. My plan is to have the students program a small Arduino microcontroller to log altitude (maybe g's) and it would be logic to have it trigger the servo when altitude stats to drop again
+Ole Brinch Sorry for the late reply. An altitude based deployment system would be the way to go. We used a timer based system since that's what we had on hand. Commercial model rocket altimeters typically only have a pyro output for firing ejection charges and so you would also need a servo controller for this deployment mechanism. Unfortunately neither of the altimeters we have, have an apogee signal output otherwise we could route it directly to the servo timer. Sounds like a good plan for the students to use a small Arduino board for the controller. Best of luck with your flights.
Where can I get details of parachute deployment mechanism? Please reply
There you go: www.aircommandrockets.com/construction_7.htm
How is the parachute coming out of the rocket?
The nosecone is ejected by rubber bands and the nosecone pulls the parachute out.
How does the breakwire work?
+Britt Smith The break wire is just two wires twisted together with a string loop in between that's attached to the ground. When the rocket launches the string loop gets pulled out between the wires separating them in the process. When they separate they break the electrical connection which then starts the timer. More info on the break wire here: www.aircommandrockets.com/servo_timer_V2_0.htm#_tip5
+AirCommandRockets Thanks for the quick reply
I'm wandering, do you do this just as a hobby or something else? Because the rocket looks very professional! Mine is very simple, and not reliable yet, however we get loads of fun. Working now to make it more reliable. If you wander it's here with the parachute deployment explanation and demonstration: ruclips.net/video/sznkx21Y2Eg/видео.html