BigBlueDart
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I painted the main section on Christmas Day, then removed tape and vinyl lettering while video chatting with family that lives in a much colder climate:
You weren't kidding when you said you started this rocket "a long time ago..." at last months meeting.
Looks like its been a good learning process. Decided what you want to fly this on first?
I'm curious about your choice to do shear pins on the booster.
(and have you though about brass strips inside the tube? cardboard doesn't shear them as well as fiberglass I've heard)
Oh, and I think I'll probably be flying it on the highest thrust 'I' motor I can find as a first flight because I'll need to recertify. I didn't keep my TRA membership up after I got Level 1 the first time.
I'm not sure exactly what you mean about the brass strips, but I'm open to other ideas if it's something I can still implement. I settled on the 2-56 nylon screws based on the advice of some other club members. I did pour some CA through the holes and then redrill them for a little extra strength, but I recognize that even flexible phenolic tubing won't hold up like that forever. If I make it to the February club meeting you can tell me more there (and you'll have to remind me who you are as I really haven't gotten to know folks yet).
All this was going on over the course of the Spring. After that I entered another phase where I got busy in life and/or the weather wasn't good for painting. But at some point in the middle of everything posted above I also started working on my avionics bay:
And yes, I know that last picture of the back of my sled is hideous. This is my first avionics bay, so I'll likely look at some other designs and work on something more elegant for future builds.
Well, that about sums everything up for now. My biggest hurdles are mostly financial as I still need parachutes, a second altimeter, and a motor. In the meantime I am working on finishing up my avionics bay. I'll post pictures of that once it's further along.
You weren't kidding when you said you started this rocket "a long time ago..." at last months meeting.
Looks like its been a good learning process. Decided what you want to fly this on first?
I'm curious about your choice to do shear pins on the booster.
(and have you though about brass strips inside the tube? cardboard doesn't shear them as well as fiberglass I've heard)
I'm not sure exactly what you mean about the brass strips, but I'm open to other ideas if it's something I can still implement. I settled on the 2-56 nylon screws based on the advice of some other club members. I did pour some CA through the holes and then redrill them for a little extra strength, but I recognize that even flexible phenolic tubing won't hold up like that forever.
Regarding the brass strips for shear pin cutting. Here's what I did with mine built out of the same material (flexible phenolic). I bought 1/2" wide brass strips from HobbyTown. They have different thicknesses. I don't remember which thickness exactly. I think I used .015". Cut pieces 1/2"x1/2". Mark their location on the body tube inner surface. Cut down 1 layer of tube and peel it out. Cut as many layers out until the brass strips are flush with the inner surface of the body tube. Do the same for the outer surface of the couplers. If you drilled the holes first, perfect. Epoxy the brass strips into the recesses. Then realign the body over the coupler and redrill the holes through the brass. Viola! Instant shear pin shears. The plastic shoulder of my nosecone was a more difficult challenge, but basically the same process, just with a dremel and sanding drum instead of peeling layers. I use three 1/16" styrene rods for mine on both ends. Stuff it in the hole and snip off the rod. When I run out of styrene rods, I'll switch to 2-56 nylon screws.
Hope this helps.
Adrian
Looks good. I'll make a few comments here and there. First. You should probably change out you eye bolts with closed eye bolts. Either cast or if those aren't stainless, weld them closed. You don't want them to pull open. It can happen...
Regarding the bulkhead cover over the motor mount; you realize that limits the length motor you can install, right? Hopefully, you left enough space to fit a CTI 54mm 6XL case in there, or the new AT 54/2800. That K990DM for the 54/2800 is awesome!
Regarding the brass strips for shear pin cutting. Here's what I did with mine built out of the same material (flexible phenolic). I bought 1/2" wide brass strips from HobbyTown. They have different thicknesses. I don't remember which thickness exactly. I think I used .015". Cut pieces 1/2"x1/2". Mark their location on the body tube inner surface. Cut down 1 layer of tube and peel it out. Cut as many layers out until the brass strips are flush with the inner surface of the body tube. Do the same for the outer surface of the couplers. If you drilled the holes first, perfect. Epoxy the brass strips into the recesses. Then realign the body over the coupler and redrill the holes through the brass. Viola! Instant shear pin shears. The plastic shoulder of my nosecone was a more difficult challenge, but basically the same process, just with a dremel and sanding drum instead of peeling layers. I use three 1/16" styrene rods for mine on both ends. Stuff it in the hole and snip off the rod. When I run out of styrene rods, I'll switch to 2-56 nylon screws.
Hope this helps.
Adrian
Oh, and I think I'll probably be flying it on the highest thrust 'I' motor I can find as a first flight because I'll need to recertify. I didn't keep my TRA membership up after I got Level 1 the first time.
The joint between my main body tube and the fin can section had a bit of a gap due to unevenly cutting the body tube. I decided to try fixing this by filling it in a bit with epoxy and filler. I wrapped the coupler in plastic wrap and then slid the body tube over it. Then I pulled the plastic back up and filled in the gap. The plastic protected the main body tube and kept the pieces from getting stuck. The result wasn't perfect, but it was much improved:
Neat trick, especially if/when a rotary sander isn't available. I'm very pleased you decided to update this thread - it's a very cool build and I love the attention to detail.
No need for fancy tools for that. Wrap a standard piece of paper around tube and tape in place, then draw a line at the edge that needs trued up. Then just use a block of wood and sandpaper and sand to the line. Just takes a few minutes, super simple.
Oh yes, what brand of nose cone is that? PML?
The IRIS will always have a place in my fleet. Absolutely EXCELLENT build!!!
One of my rocketry regrets, was not getting your Yank 5.5" IRIS when I got the 4" one. Silly me, I thought one IRIS was enough... Please tell me you might bring back a flexible phenolic 5.5 IRIS again.
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