Birthday Candle Speed Build...

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snrkl

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OK: so to see what happens with a 6m streamer, I decided to build a birthday candle (we have a birthday girl in the family next weekend at my local launch)...

Initially designed for BT60, I decided it was a little heavier than I was happy with for a streamer recovery...


OR downscaled to BT55, and we are off to the races...
View attachment Candle_2_BT55 Scale.ork
OpenRocket024.jpg
OpenRocket026.png
 

snrkl

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So I've built the MMT, the beginnings of the transition can and the transitions.

ImageUploadedByRocketry Forum1504259616.751580.jpg

I'm a little worried about the strength of the bt5 candle wick, and was trying to figure out what I could strengthen it with, when I had a brainwave: the wax paper drinking straws I use for launch lugs:

ImageUploadedByRocketry Forum1504259703.898275.jpg
A triangle of three of them fits perfectly, so once the can is assembled, I'll glue the trio into the inside of the wick BT.

I'm also going to use a 24mm punch out left over from a laser cut CR to bulkhead seal the bottom of the bt5.
 

snrkl

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One small modification I'm thinking of - making the fins perfect semicircles.

The thought of having to curt circles tonight in balsa pains me as my circle cutter is out of blades....

This way I can use a handy coffee can as a template...
 

dhbarr

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This is very clever, nice!
 

Gary Byrum

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Here's an idea to strengthen tubes that I used that makes them nearly as stiff as plastic. I mopped the inside with a sponge on a dowel until it was saturated. You can be pretty certain that BT-5 will will be strong enough. POST #21.

As for the fins, have you considered using old CD's or DVD's split in half?
 

snrkl

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Here's an idea to strengthen tubes that I used that makes them nearly as stiff as plastic. I mopped the inside with a sponge on a dowel until it was saturated. You can be pretty certain that BT-5 will will be strong enough. POST #21.

As for the fins, have you considered using old CD's or DVD's split in half?
I considered it - but CA is expensive and fumey - these straws were free (someone I know's kid dropped a whole packet in the dirt - no good for drinking, plenty good for rockets!)

Also, CA can make stuff brittle - these will make the wick neck more stress resilient. And I'm not worried about the extra 6g of weight... 😉
 

snrkl

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Update: had to remake the transitions - hand cut was just too wonky and they didn't fit well - tried to CA the narrow ends to allow some sanding and they split on attempted installation.

I managed to resuscitate my circle cutter (the tip snapped and I found a sharp bit of the blade again)

New transitions are much more cleanly cut... we'll see how they fit in the morning.
 

snrkl

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Nice fit on the transitions.

I realised I needed to add a shoulder to the top of the wick can. The 5mm piece of BT was too hard to slide due to its size, so I sliced, wrapped, glued it.

There was a small gap when I put the nosecone BT on the wick - whether glue locked up or there was glue from the can creation that made it too tight is unknown.

I also accidentally bruised one of the transitions in a dry fit.. doh!

ImageUploadedByRocketry Forum1504320121.562524.jpgImageUploadedByRocketry Forum1504320135.632672.jpg

No matter - nothing CWF can't fix:

ImageUploadedByRocketry Forum1504320155.608638.jpg

Once it's dry, sand 98% of it off, then I'll be CAing the red coupler shoulder to make it the nose cone.

Still haven't gotten around to cutting fins - full 1/2 circles don't look as good (root chord is too long) and making them the same root cord length reduces stability too much.

I'll probably keep them as ellipsoid but I'm resisting cutting just now while I ponder in the background.

I've also done the math for painting the spiral - I'll make two lines on opposite sides of the BT and I'll divide the line into 5 segments - I'll use the lines as line up points for the masking tape spiral wrap when I paint the pink.
 

Tonimus

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Why not just follow the spiral in the body tube for the paint job?
 

snrkl

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Two reasons:

1) not enough turns to look good
2) only one spiral visible - I need Two, each on opposite sides.
 

snrkl

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CWF sanded and CAd

ImageUploadedByRocketry Forum1504360666.732942.jpg
 

snrkl

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Fins on... 5min epoxy as I've CA'd the paper on the fin all the way down to the root edge (but not the actual root edge)

Fillets being done two at a time.

ImageUploadedByRocketry Forum1504533759.009809.jpg
 

Micromeister

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Well Shoot! When I saw this post I thought we had another Odd-Roc builder. Alas it's another cute by simple 3F&NC rocket.

Good looking paint pattern and concept although I think it would have been a better looking candle if the fins were made of Clear Polycarbonate instead of painted wood.

I've been flying a couple Christmas Candles with Holders Odd-Rocs for several years. Original flys on the Oop 10.5mm apogee A2 motors, the smaller is a T2+ minimum dia. Micro-Maxx powered Christmas theme Micro Odd-Roc.

Both Fly very nicely on their respective motors , However I'm neally out of A2's.

Yours looks to be a very nice flying rocket.

610a01-sm_10.5mm-Candle&Holder_12-23-00.jpg


267a-sm_MM CandleStick & Holder OddRoc_11-24-02.jpg


267Lp08a_MM Christmas Candle on pad_12-18-10.JPG


Christmas Theme Odd-Rocs & Weather-b_Narhams SportLaunch_12-18-10.JPG


Christmas Theme Micro Odd-Rocs(7of8)_12-21-13.JPG


MM 267Lp14a_MM Christmas Candle on Pad(14th flt)_12-12-15.JPG
 

snrkl

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Two quick items to add:

1) when designing our own nose cone, remember to put something to attach it to the rocket when it goes "pop"... (retrofit being pondered right now...)

2) paint! ImageUploadedByRocketry Forum1504676066.168887.jpg
 

les

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Looking good. Nice blend of the yellow and orange
 

Tonimus

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I dig the paint on the nose cone. Looks good.
 

snrkl

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Wrapping tape in a spiral is harder then it seems!

Progress update
ImageUploadedByRocketry Forum1504777036.507410.jpg

Pink is in demand for another furniture project for the 7yo step daughter' upcoming 8th birthday so green it is!

Left to do: fins, wick and figure out some method of NC attachment (design / construction oversight...)
 

GlenP

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Well Shoot! When I saw this post I thought we had another Odd-Roc builder...Alas it's another cute [but] simple 3F&NC rocket...
is this just a backhanded compliment? Or are you starting a FLAME war? :)

I have heard of flame fins on a Dr. Zooch kit, but never have seen a flame nose cone before. These candle stick rockets are really cool, must be hard work to come up with these clever concepts, burning the candle at both ends, I see.

A fin profile in the shape of a cupcake on that candle would be neat:
Screen Shot 2017-09-07 at 6.20.06 PM.png
 

snrkl

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I considered the cake fin profile, but the time required trying to get this for launch this weekend made the decision for me.

Plus, I didn't want brown fins... ;-)
 

BABAR

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Wrapping tape in a spiral is harder then it seems!

Progress update
View attachment 327569

Pink is in demand for another furniture project for the 7yo step daughter' upcoming 8th birthday so green it is!

Left to do: fins, wick and figure out some method of NC attachment (design / construction oversight...)
Colored electrical tape works great for putting a spiral tape design, as it is malleable and will adapt to the curve nicely.
 

snrkl

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NC retainer retrofit:

Carefully removed the bulkhead over the structural drinking straws

ImageUploadedByRocketry Forum1504912069.289930.jpg
ImageUploadedByRocketry Forum1504912106.744176.jpg

Sanded inside them to improve glue bite
ImageUploadedByRocketry Forum1504912133.428675.jpg

Notches on some light disposable chopsticks and some Kevlar tied:

ImageUploadedByRocketry Forum1504912143.692892.jpg

ImageUploadedByRocketry Forum1504912185.910992.jpg

Used an emery board to make angled glue retention abrasions on the chopsticks.

Then I injected 5min epoxy into each straw, carefully turned the chopstick/shock cord combo into each straw then let dry.

I was able to use the emery board as a careful saw to trim the excess chopsticks once dry ( carefully using my nail to cover the shock cord lest I saw through it)

Then the whole thing was coated with another layer of epoxy.

Tested the strength - I couldn't pull it out with everything I had - it's not going anywhere.

ImageUploadedByRocketry Forum1504912397.974493.jpg
 

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