Custom Mini Christmas tree rocket build
- Thread starter Adam3836
- Start date
Help Support The Rocketry Forum:
Now you need a Nutcracker rocket to complete the set!
Still a ways to go, but I think it's coming together nicely so far...
Been cross posting, but I actually love this old guy now! Lol
My third one and first to be done!
(Decorations and lap present are from my Amazon tree and lights from the Hobby Lobby tree.)
My third one and first to be done!
(Decorations and lap present are from my Amazon tree and lights from the Hobby Lobby tree.)
High Desert Rocketry
Well-Known Member
- Joined
- Mar 21, 2011
- Messages
- 916
- Reaction score
- 793
This year's Christmas tree launch at FAR by Xyla and friends
Last edited:
I was surprised it did imo poorly considering they had launched one last year. I feel the rear fins are too large which probably had the cg too far back. They should've tried a swing test!
Speaking of swing test...
I built up Tree #2 with Viking Bulk kit and I think it looks pretty cool! I still want to add lights, but it's proving to be a challenge to figure out the best way. I've thought of several including mounting the battery sealed in the nose cone with wires coming out, having the battery through the forward bulkhead and a switch and a few others.
In the meantime I figured I'd try a swing test to see how much nose weight I need and it was very stable without any! (Q-Jet C16-4 loaded)
I built up Tree #2 with Viking Bulk kit and I think it looks pretty cool! I still want to add lights, but it's proving to be a challenge to figure out the best way. I've thought of several including mounting the battery sealed in the nose cone with wires coming out, having the battery through the forward bulkhead and a switch and a few others.
In the meantime I figured I'd try a swing test to see how much nose weight I need and it was very stable without any! (Q-Jet C16-4 loaded)
Mine should fly Saturday. If I don't freeze my tookus off first. It's 11:45pm and 19 degrees F.
I live on a lake and I first started rocketry launching off the ice in the winter...definitely "freezing tookus" weather!
Advice: Dress warm (duh lol) and use hand warmers (the foot ones are half size and are easily inserted into gloves...the regular ones too, but they're big and can get too hot).
I also keep rocket motors inside my jacket to limit temp cycling.
I was originally planning on launching this weekend, but now I'm thinking of waiting for my daughter to return from college and so I'll launch next weekend at my local park. Just have one more "tree of three" and I've settled on a design for it.
dpower
Well-Known Member
- Joined
- Jan 18, 2009
- Messages
- 1,866
- Reaction score
- 511
Really like to see the enthusiasm, teamwork, and leadership in a new generation of engineers! (from an engineer still going after 40 years in the profession)
Nice launch too.
The Christmas tree rocket flew. Put it up on an F32. I severely miscalculated the drag. Thrustcurve gave me an altitude id 1500' with an 8 second delay. I should have use a G78-4. The rocket made maybe 500'. Ejection charge went off about 10' above the ground. Crumpled BT. Easy fix. It will fly next year.
Ooh, sorry to hear about the crumple, but great to hear it at least flew. I was waffling on my initial choice of motor for my builds and last night decided to go with D16-4 instead of C12-4 since I was picturing a low draggy flight and very late ejection.
Swing test on Tree1 (but last to be built) initially was poor with it aft backwards, but then I noticed my skirt was being blown up to the tree (tee hee!).
After starting it pointy side forward and letting the skirt settle/drape as it should, it ended up very stable with no nose weight and a D16-4 loaded.
The tree skirt was a good idea since it was just draggy enough, but not as much as a disk.
Last edited:
I wasn't happy with the fat nose cone star on my Tree #1 and a swing test with the skirt in place was stable even without the nose cone, so I ditched it.
However, the tree looked too plain now, so I had to "spruce" it up.
I found little stars to top the tree, but only blue ones were left (on clearance!), so blue Christmas star it is!
To make it 3D, I cut one in half and added grooves to both sides of another and epoxied. I also found a tiny pretend Christmas light strand.
I then epoxied the star on and did another swing test and it was still stable!
Looking much better now!
So I plan to launch this soon, however the weather outside is frightful.
Either warm with rain tomorrow or single digit cold Saturday & Sunday...and all days are windy. Ugh.
I'll try tomorrow morning unless it's raining too hard (although the plastic tree and Santa's Little Leaper may be OK).
However, the tree looked too plain now, so I had to "spruce" it up.
I found little stars to top the tree, but only blue ones were left (on clearance!), so blue Christmas star it is!
To make it 3D, I cut one in half and added grooves to both sides of another and epoxied. I also found a tiny pretend Christmas light strand.
I then epoxied the star on and did another swing test and it was still stable!
Looking much better now!
So I plan to launch this soon, however the weather outside is frightful.
Either warm with rain tomorrow or single digit cold Saturday & Sunday...and all days are windy. Ugh.
I'll try tomorrow morning unless it's raining too hard (although the plastic tree and Santa's Little Leaper may be OK).
Merry Christmas! 
I went launching all three around 1PM today and got video, which I'll try to load later, but here are the initial reports:
I went launching all three around 1PM today and got video, which I'll try to load later, but here are the initial reports:
- Santa's Little Leaper: Low, slow and fine but landed on his head (which remained intact).
- Tree #1 (Amazon little traditional tree): one swirl on the way up, so not stable, but very close and should be good with some nose weight. Likely issue is the odd shaped and arranged branches.
- Tree #2 (Hobby Lobby clear lighted tree): not stable and swirled a few times, then hit the ground. Needs nose weight.
Last edited:
I should add that it was cold and windy...I often had to wait for the gusts to die down a few times.
My buddy and I have launched our Leapers a number of times, and only once has it landed upright.
Not stable but ranks high in entertainment value.
- Joined
- Aug 27, 2011
- Messages
- 11,636
- Reaction score
- 6,282
if you put a big enough motor in it, it WILL finish the flight needlelessly complicated.
Hi Babar, that could help...in thrust we trust!
However, in these cases the max liftoff weight specified for the D16 Q-jet is about twice the total weight of the loaded rockets.
Personally (and embarassingly for someone who likes oddrocs), I suspect that the issue was asymmetry...these trees were not symmetrical and it was windy. Additionally, the thrust may have been off-axis (motor tube isn't directly in the centerline of the tree).
Asymmetry apparently allows the rockets to pass the swing tests yet stray and spiral or loop.
I may try more things to get them stable as I get the chance. Thanks!
Last edited:
i suspect many folks on this thread, if given a Rorschach test, would answer, "...oooh that's a rocket..."
lakeroadster
When in doubt... build hell-for-stout!
I'm betting the Kringle 3000 just had a short in the thermocoupler..... something I learned that from Papa Elf
- Joined
- Aug 27, 2011
- Messages
- 11,636
- Reaction score
- 6,282
Lol, there was a word replacement in my previously reply which my immature sense of humor thought would be appreciated
. Probably would only apply to flying REAL trees AFTER Christmas, which nobody should do anyway.with all due respect to those who subscribe to the “In Thrust We Trust”, with the exception of tractor motors, since I started scratch building I have always been dubious about solving every problem with added nose weight and added thrust.
you add nose weight and definitely makes it more stable by pulling CG forward
but if the added nose weight precludes you from get a draggy OddRoc off the rod or rail with sufficient velocity, you have to add more motors in the tail, which brings the CG backward
so you add MORE nose weight……but then……
you can see how this may end up both literally and figuratively having your rocket design chasing its tail.
my go to solution for instability has usually been to increase the tail feathers AND the thrust. Agreed the added fin surface area does have a cost in both weight and drag, but particularly for rockets that start with a far forward CP, it seems more efficient than just throwing in more nose weight.
Last edited:
The Kringle 3000 is placed well to offset asymmetric drag but is a real problem for that CP- CG relationship. You then need a really big, heavy and powerful Rudolph up front...and Dasher and Dancer and Pranced and Vixen, Comet and Cupid and Doner and Blitzen. All canted tractors out of Rudolph's collar and kiesters of the other Reindeer team. Plenty of tinsel following behind Santa's sleigh for added base drag. A true RSO frightening machine.
Similar threads
