Redshift- 38mm Minimum Diameter Rocket

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Those guides are very awesome, love the font! I've been 3-D printing stuff with my high schools new 3-D printer, and putting text on the objects is always really fun and cool looking. Its something unique to 3-d printing in that it can be done without much added cost or time.

Nate, its looking great so far! If its ready by februarys launch, I'll be sure to have my GoPro film those new rail guides in action, I'm quite curious to see how they perform.
 
RocketHunter said:
Those guides are very awesome, love the font! I've been 3-D printing stuff with my high schools new 3-D printer, and putting text on the objects is always really fun and cool looking. Its something unique to 3-d printing in that it can be done without much added cost or time.

Nate, its looking great so far! If its ready by februarys launch, I'll be sure to have my GoPro film those new rail guides in action, I'm quite curious to see how they perform.
Click to expand...

WWWooooowwwwwww.....
Is that a good idea................

Teddy
 
Just talked to Mark about the decal- I'm starting to get excited about this, I can't wait to it!

Oh, and I tacked the last fin. Pics forthcoming

Nate
 
Rail guides are in the mail. I'll send some instructions in the next day or two
 
Got some work done yesterday and this morning.

First, like I said, I got the last fin on. Yay!!

20150127_104311.jpg20150127_104324.jpg

The method of using the 720 case in the tube to keep the epoxy from seeping in worked perfectly. The parchment paper never stuck, there was really no sanding needed, and the cases fit great!


I also made up a nosecone bulkhead. I've really been thinking about trying to put the tracker in the NC, but without a threaded tip, I decided it just wasn't worth the extra weight and effort to try to come up with a workable way. I thought about foaming the cone, cutting out a section for the tracker, installing threaded inserts in the foam, and then making a bulkhead that would have holes drilled to mount into those threaded inserts, but decided, after doing a couple test fits with an, ahm, stand-in tracker, decided it was easier to just tape it to the shock cord, as Chuck describes here: https://www.rocketryforum.com/showthread.php?57788-Mounting-a-Tracker-to-Your-Shock-Cord That's not the same tracker I'm using, but I think I'll be able to figure out a way to make it work.


Here's the bulkhead: 20150127_104209.jpg

I have a nut tied onto the backside, so that it won't pull through. This will be epoxied as far up into the nosecone as I can get it, so as to give me as much room as practically possible to pack the tracker, parachute, etc.




I also cut some kevlar, and mocked up my main parachute setup. There's 10 ft. of 1/8" tubular kevlar, stand in tracker (1"X2" piece of plywood duct taped to cord)
20150127_104151.jpg

I'm thinking I'll go with the 15" chute. I'm looking or opinions on thin mill vs. regular. If this thing is falling fast on a streamer, will the thin mill hold up?

Nate
 
Im going with an 18" thin mill that will be deployed at the 20,000ft apogee and fall like a streamer with a cable utter which will open up at 300-500'. I think you'll be fine :)
 
nute said:
Got some work done yesterday and this morning.

First, like I said, I got the last fin on. Yay!!

View attachment 253085View attachment 253086

The method of using the 720 case in the tube to keep the epoxy from seeping in worked perfectly. The parchment paper never stuck, there was really no sanding needed, and the cases fit great!


I also made up a nosecone bulkhead. I've really been thinking about trying to put the tracker in the NC, but without a threaded tip, I decided it just wasn't worth the extra weight and effort to try to come up with a workable way. I thought about foaming the cone, cutting out a section for the tracker, installing threaded inserts in the foam, and then making a bulkhead that would have holes drilled to mount into those threaded inserts, but decided, after doing a couple test fits with an, ahm, stand-in tracker, decided it was easier to just tape it to the shock cord, as Chuck describes here: https://www.rocketryforum.com/showthread.php?57788-Mounting-a-Tracker-to-Your-Shock-Cord That's not the same tracker I'm using, but I think I'll be able to figure out a way to make it work.


Here's the bulkhead: View attachment 253087

I have a nut tied onto the backside, so that it won't pull through. This will be epoxied as far up into the nosecone as I can get it, so as to give me as much room as practically possible to pack the tracker, parachute, etc.




I also cut some kevlar, and mocked up my main parachute setup. There's 10 ft. of 1/8" tubular kevlar, stand in tracker (1"X2" piece of plywood duct taped to cord)
View attachment 253088

I'm thinking I'll go with the 15" chute. I'm looking or opinions on thin mill vs. regular. If this thing is falling fast on a streamer, will the thin mill hold up?

Nate
Click to expand...

Nate, thats coming along awesome! I love how min. diameter rockets go together so easy - just glue on the fins, set up your dual deploy system, and you're ready to go!

As for the chute, the thin-mil is probably fine. (my BH38 I think is using a 24'' thin mil, I'm not 100% sure though, it was the parachute included in the kit). I would just go with with whatever fits - if you can fit the regular, it can't hurt to have a bit more strength.
 
conman13 said:
Im going with an 18" thin mill that will be deployed at the 20,000ft apogee and fall like a streamer with a cable utter which will open up at 300-500'. I think you'll be fine :)
Click to expand...

20K!! That's crazy!

RocketHunter said:
Nate, thats coming along awesome! I love how min. diameter rockets go together so easy - just glue on the fins, set up your dual deploy system, and you're ready to go!

As for the chute, the thin-mil is probably fine. (my BH38 I think is using a 24'' thin mil, I'm not 100% sure though, it was the parachute included in the kit). I would just go with with whatever fits - if you can fit the regular, it can't hurt to have a bit more strength.
Click to expand...


Thanks for the suggestions guys, I might just be able to fit the larger 15" chute, or even a 24"... ( Idon't have a serviceable 18" right now- working on that...)

... in part due to a little change of plans:

I was looking at my nosecone bulkhead, and noticed a small piece of FG left over from another part I was making. it was an even smaller disc, and I had a little bit of a brainwave. I decided if I'm going to recess it a little bit, why not recess it a lot!

And so, I made up a new NC attachment system, and I like it. I like it a lot! It should give me access to the vast majority of the space inside the NC, allowing for everything to pack a little easier:


20150127_134434.jpg20150127_134449.jpg

Nate
 
Question that should hopefully provoke some thought: Why apply the duct tape to the loose ends of the Kevlar? This practice will make the Kevlar inflexible at that point and could impede you from packing it as tight as possible. Tying secure knots that don't require tape to hold the loose ends may be better and alleviate some of that concern.

A good alternative may be to apply some heat shrink tubing over the actual knot itself to keep it tight. That will keep the knot snug while adding very minimal volume.
 
hard to tell from the pictures, is that a real knot? there are several knots that work very well on smaller kevlar but a simple single overhand loop will hold very well and take up minimal space if you don't need to get it apart. I tie the loop on the shock cord large enough to slip it over the nose or coupler. that way I can pass the shock cord through the eye bolt or nosecone/ebay loop, then pass the nosecone or ebay through the shock cord loop. then they are looped together without the need of a quick link. easy to remove as well. also, to keep the kevlar from fraying I tape it tightly with masking tape and cut in the center of the tape. then add a drop of superglue to the cut ends. if you time it right you can pull the tape off before the super glue is fully set up and you have a nice clean end.
 
Yes, there's a knot there :)

I'll see what I can do to streamline this system- Mostly the duct tape is just there to keep the frayed ends from going everywhere, and to give me ease of mind that nothing will pull free.

RKeller, I'm not sure I quite understand what you mean with the passing through, etc, but thanks for the tip about cutting the ends. I used a similar method, but never thought to use superglue.

Nate
 
nothing fancy, I just suck at explaining things.
001.JPG

002.JPG

003.JPG

004.JPG
 
RKeller said:
nothing fancy, I just suck at explaining things.
Click to expand...

Hey, that's a good way of doing it!
Oh, and your explanations are pretty good, especially compared to some people I know. "you know that thing I was talking about, yeah? It like, well, it **gestures madly** yeah. You know what I mean?" :)

I removed the tape from the joints and retied the knots. I put a bit of masking tape on one end of the loop. It packs much better now. I epoxied the bulkhead in, and ordered the battery and charger from Sparkfun. $7 for the battery, $8 for the charger, and $12 for shipping. :y::surprised: Ouch.

Nate
 
Well, Mark's done it again! I got an email last night saying they were on their way. Even with a full time job, he went from design to mail in 2 days flat! :w:
The fly away guides should be here today, assuming the usps people cooperate...


Nate
 
Progress!

I epoxied in the NC bulkhead- no pics because it's rather difficult to take a picture inside of a 38mm black NC...

I also received the rail guides today! Thank you Bill!! These things are truly awesome. I don't have a rail to play with, but I can tell they should work awesomely. There is really very little force on the guides when they are closed. like Bill said, you kinda have to feel them in your hand to understand how it works. once they start to open though, there's plenty of force pulling them open. The hinge works perfectly, and the fit on the tube is near impeccable.

Pics. 20150129_191249.jpg20150129_191312.jpg20150129_191158.jpg20150129_191153.jpg20150129_191143.jpg20150129_191131.jpg



In the one picture, they're fitted onto a Formula 38, since Redshift is getting fillets.


Needless to say, I also started on fillets.

I'm using Rocketpoxy tinted black and a 29mm motor tube to pull them. Yes, they're rather large. With no tip to tip or other FG reinforcement, I figured I'd try to keep the fins on with fillets.

Pics: 20150129_194734.jpg20150129_194722.jpg

They look better in real life, the pictures are a bit misleading.

Nate
 
I'm looking forward to this flight. Find someone with a fancy GoPro and take some high-speed video :)
 
nute said:
Progress!

I epoxied in the NC bulkhead- no pics because it's rather difficult to take a picture inside of a 38mm black NC...

I also received the rail guides today! Thank you Bill!! These things are truly awesome. I don't have a rail to play with, but I can tell they should work awesomely. There is really very little force on the guides when they are closed. like Bill said, you kinda have to feel them in your hand to understand how it works. once they start to open though, there's plenty of force pulling them open. The hinge works perfectly, and the fit on the tube is near impeccable.

Pics. View attachment 253403View attachment 253404View attachment 253405View attachment 253406View attachment 253407View attachment 253408



In the one picture, they're fitted onto a Formula 38, since Redshift is getting fillets.


Needless to say, I also started on fillets.

I'm using Rocketpoxy tinted black and a 29mm motor tube to pull them. Yes, they're rather large. With no tip to tip or other FG reinforcement, I figured I'd try to keep the fins on with fillets.

Pics: View attachment 253409View attachment 253410

They look better in real life, the pictures are a bit misleading.

Nate
Click to expand...

Haha I'm doing the same with my mach 2 38mm md build, no T2T but I'm going to make huge JB Weld fillets to hold the fins on.
 
conman13 said:
Haha I'm doing the same with my mach 2 38mm md build, no T2T but I'm going to make huge JB Weld fillets to hold the fins on.
Click to expand...

Yeah, I was going to use smaller fillets, but I decided I didn't want fiberglass, motor parts, and electronics falling from 8K...

Nate
 
Last edited:
wfcook said:
Jb weld is heat resistant...but not that strong.
Click to expand...

Ive talked to a bunch of high performance md flyers and they have all said JB Weld will work fine. Sure it may not be as strong as something like rocketpoxy or proline but it gets the job done just fine :)
 
conman13 said:
Ive talked to a bunch of high performance md flyers and they have all said JB Weld will work fine. Sure it may not be as strong as something like rocketpoxy or proline but it gets the job done just fine :)
Click to expand...

That is true I am sure. I just wanted to point out that if not for its ability to handle high temperatures we probably wouldn't use the stuff. I don't anticipate it will make the difference on whether the fins shred at all.

I think Nate's doing a great job.
 
conman13 said:
Ive talked to a bunch of high performance md flyers and they have all said JB Weld will work fine. Sure it may not be as strong as something like rocketpoxy or proline but it gets the job done just fine :)
Click to expand...

JB weld is good to mach 2.2+ with MUCH MUCH smaller fillets than you used. If your prep was good you will have zero issues.
 
maxvelocity said:
JB weld is good to mach 2.2+ with MUCH MUCH smaller fillets than you used. If your prep was good you will have zero issues.
Click to expand...

Ya I may need to rethink what epoxy I use for fillets.... The rocket is simming to mach 2.4 and I'd rather be safe then sorry. Maybe rocketpoxy? Sorry to derail your thread Nate :(
 
conman13 said:
Ya I may need to rethink what epoxy I use for fillets.... The rocket is simming to mach 2.4 and I'd rather be safe then sorry. Maybe rocketpoxy? Sorry to derail your thread Nate :(
Click to expand...

Hey, no problem- If it's relevant discussion, It's welcome on any thread of mine :)
Besides, I have no updates to speak of, although I'm planning to start painting the NC today.

Oh, and I highly recommend Rocketpoxy. I love the stuff.

Nate
 
Alright, now WITHOUT starting a war... I'd like opinions on shear pins. I've never used them before, and have never seen any evidence of a main prematurely deploying or starting to deploy. I like the simplicity of friction fit, but is there something else I should know?

Nate
 
RocketHunter said:
Nate, thats coming along awesome! I love how min. diameter rockets go together so easy - just glue on the fins, set up your dual deploy system, and you're ready to go!
Click to expand...

Absolutely- It's really interesting and fun to be simultaneously building this, a small, simple MD rocket, and also a Madcow 4" Pike, which is huge, with lots of internal structure, and a massive AV-bay. They're practically polar opposites, and yet should fly on similar motors :)

Nate
 

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