Thinking about my second rocket build.. (24mm MD D11)

[snrkl]

[Title typo - I meant D12]
So I've built and flown my first rockets (modelled after Grant Thompson's Randomizer Rocket

[video=youtube;r2lDXoW78u0]https://www.youtube.com/watch?v=r2lDXoW78u0[/video]

MINUS the home built sugar motors, preferring an Estes D12) and I've enjoyed the process, the iterations and the learning.. It is also extremely satisfying to have my first rockets completely scratch built...

I am now thinking about my next project, and I am looking at something using more common rocketry components but I am not keen on kit building... (they are pretty expensive over here, and I like the challenge of doing it all myself...)

So I am thinking about a 24mm MD flying on an estes D12 with a streamer recovery...

I started to wonder, once I started modelling it up in OpenRocket: is 511M (~1600ft) too high to be looking at a streamer or single chute recovery?

I am interested in the thoughts of those that have had a little more build/fly time under their belts...

 

[BDB]

1600' is no problem, as long as you are launching in a large field. I personally prefer streamers, when possible. There's less of a chance of it floating into a rocket eating tree.

FWIW....I haven't built the randomizer rocket, but I have made sugar motors like he describes in that video. I don't think they are really E-something power, but they are really fun to make and fly.

 

[tomsteve]

I prefer streamers,too, on md high fliers. I bought a mylar survival blanket for like $3 and have a LOT of material for streamers. I patterned my streamers after the ones on a video from apogee on making mylar streamers. with fan folding and a little heat from an iron to set the folds, im able to get some pretty big,light streamers into md rockets that are pretty easy to spot in the sky.
then on construction I keep the fins forward of the tail end of the rocket- something like nike style fins- and mount them about 1/2" from the tail end of the BT.
that way theres a better chance of the motor touching down first rather then a fin edge.

 

[TRFfan]

Can you post the ORK file?

 

[AfterBurners]

Nice rocket. The only time I really kit build is basically is when it's something I can't scratch build, or I'll buy a kit to get the patterns or parts sheet and then do a scratch build later with upgraded and improved parts and other components..possibly even an upscale if its doable?

 

[ksaves2]

Listen to BDB and TomSteve. Both very good points. 1600' is not too bad as it shouldn't be outta sight for that long. That said, due to the size of the rocket it would be smart to
use a reflective mylar streamer: https://www.ebay.com/p/?iid=322489107718&lpid=82&&&ul_noapp=true&chn=ps. Buy a roll and you'll be set for life.

Use as long as you can get in the rocket. Also, try to cut it with a straightedge on a rubber surface with an extremely sharp blade. Kevlar or chainmail gloves (if you have access to
the pricey chainmail glove, use it. Kevlar is second best for the non-cutting hand and is what I use) Using rubber a mat and sharp blade avoids little transverse fractures that can occur with the mylar. It does happen if you look with magnification. The significance of the micro fractures is they can rip through with fluttering on the descent. (Been there, done that) Now if you cut a "perfect" streamer and still have a few micro fractures (or none for the matter) I reinforce the edges with a strip of Scotch tape on both edges of the streamer. You don't have to put the tape on both sides but a long stripe down each side. Yeah, it adds thickness but it will prevent propagation of a transverse tear and ripping in two on descent.
Once the tape is in place, you fanfold the streamer starting from the end to crease it. I use a mono-kote iron to apply some heat to set the creases. (Another reason to use that
scotch tape on the edges.) I crease it as far as I care to go and I roll the streamer up when I go to pack it in the rocket.

Even if your rocket is out of sight, if there is sunlight, you will have a very good chance to see flashes off the streamer at altitude even if you can't see the rocket body.
Helps you with visual tracking (which is the name of the game if you don't have some sort of Rf tracker) on the downside and maximize your chances of recovery.

Good luck! Kurt

 

[dhbarr]

Wouldn't cutting with a hotknife obviate the tape need?

 

[ksaves2]

Wouldn't cutting with a hotknife obviate the tape need?

Maybe. If one was shooting for a streamer record one would probably go without the tape if using mylar with the understanding it could still rip and the flight wouldn't be
competitive.

In the course of several flights, small rips can develop anyways so I use the tape. I'm not breaking duration records so longevity is what I desire. Kurt

 

[TRFfan]

Most estes rockets are around this size and go about 1100 ft.

 

[tomsteve]

kurt, thank you for the info on the transverse fractures! I had one streamer pretty much fall apart after a few flights but couldn't figure out why. tonight I am going to be working with scotch tape and streamers

 

[snrkl]

Here is the ORK file for one of the iterations I am playing with...

View attachment SkySlammer_24MD.ork

 

[snrkl]

And for those interested in the flight videos, I finally pulled my finger out and got my youtube account sorted:

Launch 1: partial success - shock cord snapped. NC floated back gently, body came back ballistic...
[video=youtube;8RXS7c_bbro]https://www.youtube.com/watch?v=8RXS7c_bbro[/video]

Launch 2: picture perfect (apart from a little corkscrew) fixed the shock cord problem by making the 3wrap card shock cord mount with 4 pieces instead of three leaving one coming up over the lip of the payload tube, and a second 2x1 card over the top to match the other side of the shock cord. I wrapped with a little masking tape over the new card lip and up the shock cord a little to protect it from any hot gasses.. worked like a charm..
[video=youtube;RWfVE0R1HpY]https://www.youtube.com/watch?v=RWfVE0R1HpY[/video]

 

[car3107]

Hi - great footage - what are you using for your on-board camera?

Sent from my XT1039 using Rocketry Forum mobile app

 

[snrkl]

It was a cheap $7 808 cam clone. It died after 3-4 flights.


Sent from my iPhone using Rocketry Forum

 

[car3107]

Aha. Wonder if that's the same "u8" usb spycam thing i'm using , though the picture quality of your vids seem much better than mine... Mine seem to do weird things (e.g. video freezes, sound continues) when subjected to high g's or excessive spinning. How did your cam "die"?

Sent from my XT1039 using Rocketry Forum mobile app

 

[Cabernut]

I love launch videos. After a year, how has the ASDF held up?

 

[snrkl]

Hehe. It’s been relegated to the recycling pile... the hot melt glue for fins started to delaminate and it doesn’t go far on a d12 - I’ve moved on to better things that are lighter and cheaper to fly..


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