Redshift- 38mm Minimum Diameter Rocket

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Well the initial design sort of, um...sucked. But I have recently printed a dramatic improvement after getting acccess to a 3D printer andd being able to play with the design to get something working. Nate send me your address by PM and I'll send a set to you. They currently come in a lovely shade of Magenta by virtue of the fact that it was the cheapest color.


Wow, Thanks! That's awesome!
Not sure how I missed Connor's post, that's really cool, and it sounds like this rocket might be a good candidate for something like this.

Thanks!

Nate
 
Have you run stability analysis' for it?

I'd just been using the OR component analysis tool, but I remembered I can plot stability margin on a graph, to account for propellant burn. After doing that, it doesn't look like stability will be much of a problem in any of the possible fin sizes.

I'm still thinking about weather or not I want to modify the fins at all.

Nate
 
Not progress, really, but a bit of a brainwave I had. I can use one of the 29-38 centering rings as the SC attachment point, rather than cutting off part of the coupler. Glad I thought of that before doing any cutting.

Nate
 
OK, I have strep throat so I'm running a bit behind here, but this is the fly-away rail guide design. I don't want to hijack the thread, but before I send a pair to nute, do you guys think they are worth a try?

[video=youtube;S2fWMos7UCE]https://www.youtube.com/watch?v=S2fWMos7UCE[/video]
 
OK, I have strep throat so I'm running a bit behind here, but this is the fly-away rail guide design. I don't want to hijack the thread, but before I send a pair to nute, do you guys think they are worth a try?

[video=youtube;S2fWMos7UCE]https://www.youtube.com/watch?v=S2fWMos7UCE[/video]
PM Sent...
 
OK, I have strep throat so I'm running a bit behind here, but this is the fly-away rail guide design. I don't want to hijack the thread, but before I send a pair to nute, do you guys think they are worth a try?

[video=youtube;S2fWMos7UCE]https://www.youtube.com/watch?v=S2fWMos7UCE[/video]

Neat! I like it.
 
OK, I have strep throat so I'm running a bit behind here, but this is the fly-away rail guide design. I don't want to hijack the thread, but before I send a pair to nute, do you guys think they are worth a try?

[video=youtube;S2fWMos7UCE]https://www.youtube.com/watch?v=S2fWMos7UCE[/video]

That is beautiful. Genius design. I love it.
The only possible concern I could see would be the guides smacking one of the fins as they come off., bit if positioned correctly, it seems like they'll be clear pretty quickly.
Awesome!!
(Pm sent)

Nate

P.S..feel better! And health before rockets!

Nate
 
I think thats an amazing design that could work wonderfully!!
 
The fly always are sweet. The only issue I can see is loosing them. I wouldn't mind trying them out if you are selling.
 
A little update:

I've decided I will not be adjusting the size or shape of the fin. Partly because I don't feel I have the skills, and partly because it, and the time, effort, and most importantly risk, it entails don't fit with the goals of this project, which are to a) have fun b) gain experience in min. diameter rocketry, c) break 1 mile and mach 1, and d) look cool :)

I'm afraid that, given my inexperience, I would mess up or otherwise compromise the fins. The benefits simply aren't worth the extra time, work, and risk.

In other news, I beveled the first fin. Having had mixed success in the past getting even bevels, and no paint to hide my mistakes, it was actually rather stressful, but I think it turned out pretty well.

20150102_180834.jpg20150102_180828.jpg


Nate
 
Don't, You will ruin the blade.
Use a jig-saw with a bi-metal blade......It works!


JD

Ya the band saw would be the easiest to work with. You're probably not supposed to but I've been cutting composites on my band saw with the wood blade.
 
Don't, You will ruin the blade.
Use a jig-saw with a bi-metal blade......It works!


JD


That may be why my blade is incredibly dull now :facepalm: I will pick up a bi-metal blade as well as a new wood blade.
 
OK, I have strep throat so I'm running a bit behind here, but this is the fly-away rail guide design. I don't want to hijack the thread, but before I send a pair to nute, do you guys think they are worth a try?

[video=youtube;S2fWMos7UCE]https://www.youtube.com/watch?v=S2fWMos7UCE[/video]

Bill,,
That's just the coolest most ingenious thing I've seen in a long time...
I'm not kiddin in the least...
That really is a wonderful idea....
Absolutely amazing....
I truly believe you should offer them for sale...
There are many that'd buy them and thank you for offering something so innovative that they can not get any where else......
I have NEVER seen a rail guide snap off and away like that.....

Teddy
 
Bill,,
That's just the coolest most ingenious thing I've seen in a long time...
I'm not kiddin in the least...
That really is a wonderful idea....
Absolutely amazing....
I truly believe you should offer them for sale...
There are many that'd buy them and thank you for offering something so innovative that they can not get any where else......
I have NEVER seen a rail guide snap off and away like that.....

Teddy

Ha, they are actually based on a NARAM-52 R&D projeect by Tim Van Milligan at Apogee which you can read here, so while I agree they are ingenious, I can't take any credit really.
 
Ha, they are actually based on a NARAM-52 R&D projeect by Tim Van Milligan at Apogee which you can read here, so while I agree they are ingenious, I can't take any credit really.

OK,,
Nice of you to give due credit,,,
Still the coolest thing ......

Teddy
 
That may be why my blade is incredibly dull now :facepalm: I will pick up a bi-metal blade as well as a new wood blade.

You have to use carbide ($$) or diamond ($$$) grit blades with composites.

My college had a diamond blade that simply ate through G10 and CF without caring at ridiculous feedrates.
 
That may be why my blade is incredibly dull now :facepalm: I will pick up a bi-metal blade as well as a new wood blade.

classic%204-500x500.jpg


A jigsaw with one of those blades will cut composites like butter. I cut the fins for my first 29mm MD with the same one I just cut my L3 fins with. Still going strong. One of the best ~$5 investments i've made.

Alex
 
The remaining fins are now beveled. I think they turned out pretty well. No they're not perfect, but I'm happy.

20150104_141344.jpg
My missileworks order should be coming in tomorrow, and then I can start on the AV-bay, which is gonna be an interesting project. Currently I'm actually leaning towards he kevlar loop idea, rather than an eyebolt. Thoughts? Unfortunately, the battery missileworks recommends with their sled will be out of stock until march :y: and I'm unable to find something identical. If anyone has one they'd be willing to part with... shoot me a PM.

Next up will be fin bonding. I'm planning to follow the information outlined in the "properly bonding composites" sticky. Does anyone have info to add to that, or suggestions about it?

Nate
 
classic%204-500x500.jpg


A jigsaw with one of those blades will cut composites like butter. I cut the fins for my first 29mm MD with the same one I just cut my L3 fins with. Still going strong. One of the best ~$5 investments i've made.

Alex

$5 bucks ???
Wa da ya mean $5 bucks ???
I paid like $12 bucks for a diamond embedded jigsaw blade........
Aw mannnnn....

Cut's glass like butter though..........

Teddy
 
Agreed with all the carbide grit users. I got myself a carbide rod saw and I have never looked back.
 
A bit of progress. Click pics to enlarge
My Missileworks order arrived on Monday, and the sled looks awesome! I also got the switch I'll be using.
20150107_202623.jpg20150107_202858.jpg20150107_203124.jpg
I also got holes drilled in the Al bulkheads for the allthread. And I managed to F#$k it up pretty badly.
The process was as follows:
Mark OD and center hole of bulkhead on plywood
Measure, mark, and drill holes in plywood.
Check and recheck these holes
Use this template to mark holes on bulkheads
Use a punch to create a mark
Drill holes.

Both my dad and I thought that everything looked good at each of these steps. I'm really, really, really not sure what happened. One is good, the other is off by about 1/16" :bang::bang:My only theory is that because I was using a drill press, the bit may have not been centered in the little divet from the punch, but rather slightly off. The only other thing I can think of is tolerance stacking. ie, the mark is within 1/64 of where it should be, the divet is within 1/64 of that, and the hole is within 1/32 of that, etc.
Here's the damage **Cringes**:(

20150107_203150.jpg20150107_203203.jpg20150107_203211.jpg
I'm pretty bummed out. I considered just avoiding pics of this, but I figured if I'm gonna document the build, I'll do it right.

Regardless, I decided that given the play in the rest of the system, and after a few dry fits, this would have no effect, other than the obvious aesthetic issues...

20150107_203353.jpg:facepalm::bang:

Anyway, I'm really liking the idea of a kevlar loop rather than eyebolts, and did a little test of that:
20150107_204147.jpg20150107_204152.jpg
It's just as strong as the shock cord (obviously), lightweight, simple, and perhaps most importantly, in part since it is quite flexible, takes up next to no room on the bulkhead.

So yeah. That's what I've been doing this week. If I get any more done tonight, I'll update.

Nate
 
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What better way to spend a rainy day than building rockets, and then updating a build thread?

Anyway, I got the first fin tacked on a few days ago. I marked the location for sanding using the dowel I would use for the fillets. I covered one end with graphite (colored it with a pencil) and then pulled it as I would if I was making a fillet. This left me with an appropriately positioned mark on the BT and fin. The rest was masked and the unmasked area sanded. Then I used some fin guides I made up from payloadbay.com to hold the fin in place after applying a bead of epoxy to the fin root. A 38/720 case was wrapped in parchment and installed in the rocket for this, so that the fin would rest on that in the slot.

Pics:

20150112_172916.jpg

First fin setting up

20150118_142204.jpg

1/3 of the way there!





20150118_143923.jpg


Second fin setting up. This is starting to resemble a rocket!

I found that the one guide, when positioned correctly, is plenty capable of holding the fin in place, and is easier to use, and maybe even works better than using 2.

Nate
 

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I'll drop these in the mail this week, so hopefully you can just leave off the rail buttons...
ImageUploadedByRocketry Forum1422135953.204121.jpg
 
I'll drop these in the mail this week, so hopefully you can just leave off the rail buttons...
View attachment 252841


Duuuuuuuude!!!

Those are awesome!!
No kidding, those are seriously cool. :grin:

Bill, I am very, very excited, and incredibly appreciative of this. Thank you so much- I hope the rocket looks as good as the rail guides!:)


Thanks,
Nate
 
Glad you like it. It's a one time thing...I learned a lot printing them, and by the third try I had it right :)
 

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