|
NOW There's Enough Power
|
Name: 3E Phoenix
Built By: Tim Scott
Status: Active

Type: Kitbash
Component/Kit Mfr.: Estes Industries
|
|
|
Flight No.: 1
Event: N/A
|
Configuration: 3x Aerotech F21-7
Altitude: 1500'
Max. Velocity: 530 mph
Result: Recovered, needs repair.
|
|
Boost: After figuring out that three copperheads won't light on a 9v, or even 2 9v, we used a car battery, and the thing took off like a shot. I didn't even really see it until it was coasting. The three motors roaring to life scared most of the people nearby, because they had never heard anything like it.
Recovery: The 24" Parachute came out on cue, and while the very long, elastic shock cord took a bit of a twist as it came down, the landing should have been soft enough to not pop off a fin, but nooooo.
|
|
My first Phoenix was a catharctic experience, but it still left me wanting more. I think that was when I began to understand how thrilling it could be to have and make big rockets. The First Phoenix died a spectacular death, and was fun while it lasted, but I wanted that big beast to go higher--and faster.
I had some scrap pieces of tubing lying around, and I started playing in my head once I bought the kit to replace my first one. Since I had built my first one as it came in the kit, I figured that maybe on this one, a bit of deviation wasn't such a bad thing. As I was beginning to do things a little different, and explore what could be done, I was inding larger motors as well, which helped in the experimentation process, as well as being able to design, and simulate rockets in RockSim.
It might have been the 'Cluster Wizard' that did it, but I remember trying to figure out just how much motor I could put in the Phoenix, and what I came up with was 3x 24mm mounts, for F21s. Other than that, the kit was built per instructions. No Glassing of fins, no strengthening of body tubes, but I did add just a little bit of nose-weight... not enough in retrospect, but it was a consideration, even if the required accuracy wasn't there.
|
|
Construction was very simple. It was all per the instructions in the kit, with the exception of the motor mount. The Motor mount consisted of three pieces of tubing that were glued to each-other, and then the centering ring was made to fit them. Perhaps un-satisfactorily, two of the tubes were glued together, and then the third tube was glued straight on top of that. I figured this was the best way to make sure that all three tubes were parallel, and would stack correctly. I used the stock centering rings, because I didn't think that it would need more, and the empty space between the tubes, and all of the tube to CR joints were very well sealed with glue.
Another thing that I did was shorten the stuffer tube, so that I could get a bit more parachute in there. I knew that the chamber was a bit on the large side, but I figured that I had enough oomph behind it because I was losing pressure in the ejection chamber. Instead of two-part epoxy, which now seems like it would have been a better choice, I used titebond wood glue to bond everything together. Once I got it all together, and let it cure, it became evident that it should be sufficient enough.
The fins did come from the kit, but now that I think about it, using aircraft plywood, and TTW techniques probably would have been a better idea. On the first flight, the landing broke a fin, literally popping it off of the body tube, and breaking a portion of it off, which my recovery team failed to bring back with them. The damage is done, and there is nothing I can do about it, except... build a 4" version. Stay Tuned.
|
|