What to do with a pink crayon?!?!

[Salvage-1]

My 7 year old wants approached me last week and asked if she could come with me to the desert next time i went camping. I told her that would be an excellent idea, but it would mean that she would be coming with me to launch rockets. To my complete surprise she then informed me that she loved the idea, and could I please make her a pink rocket out of her pink crayon, like I made mine.

Ooooh Kaaay

We sat down in front of Rocksim on Sunday and came up with a few ideas. After plugging some of them through the software, she said that she liked tube fins, and liked the way I had cut some of mine at an angle, so could she have that too. She also said that she would be unhappy if I had to cut any more of her or her sisters crayon banks, and could I do it just with her pink crayon and whatever I had around. Challenge set.
She opted for 3 fins, cut out of MY other yellow crayon body. We then wrapped the tube fins inside and out with thick colored craft card and gave them a pearlescent glitter finish. You cant really see it in these pics because of the clouds, but when the suns out, these glow!

Hope she is happy with it. Fins are now attached with epoxy and have 'fillets' as best as I could give them. Now on to the motor mount. I am going to make the complete 'mount' fit with 3 centering rings, one at the rear of the bottom 'tailcone', one inside the shoulder, and one with slightly less diameter thats going to be fixed to the front of the lip that slides inside the main body tube. This is then going to be fixed to the airframe with 6 removable plastic rivets, so that I can swap the motor mount with others. I am making a single 38mm mount at the mo, which i can used with adapter and 29mm motors, I also want to make a cluster of 29's and one of 24's.

Now that its getting 'finished' there is something familiar looking about it. Daughter has named it "Pink Power", I have named it "Cray-ken".

Just tucked her in bed, and she now informs me that she has 'sharing' tomorrow, and can she please take the rocket. I now have 3 hours to finish it!!


Thumbnails, click for larger.

[o1d_dude]

Defintely a Cray-Ken.

Are you building an internal structure to house the motor mount, that is a rocket airframe inside the crayon outer shell?

Nice color scheme.

[Salvage-1]

Pics works better than words sometimes, so here are a few.


Click for larger

There are 4 centering rings. Two are inside the pink base, one epoxied against the front ledge of the transition, and one against the aft. These are both 4" and so are slightly larger than the crayon ID. The fore one of these will act as the thrust ring for the whole mount, and push against the rear lip of the rocket airframe. Since this will be flown mostly in the H range, I didnt think that this was much of an issue if it came down to structural strength of the material. Inside of aft section of airframe will also be slathered in CA. The two other rings are just to aid with centering the whole thing inside the main tube. There will be a channel dremelled into the front ring to allow it to pass the rear launch lug nut/epoxy blob inside of the airframe. The whole unit will then be secured to the rear of the airframe with 6 removable plastic rivets that will go through the aft section of the airframe and through the front plastic lip of the mount.

To provide a secure attachment point for the recovery system, I took a spare coupler that I had for a 4" tube, and formed it into a 2" 'coupler' for this airframe. Slid it 5" inside the front of the airframe and glued it there with wood glue. I then put baffle piece on the front of it and epoxied that in place with fillets front and back. There is another baffle plate that installs through the rear of the airframe and is a tight friction fit. This can be removed to clean the system out. I am also thinking of being able stick a chore boy in there for a completely removable 'no wadding' baffle. This system also means that the recovery system is moved forward quite a way and is never resting directly on any part of the motor mount.

[fyrwrxz]

Nice engineering S1-even more so is the involvement with your daughter. Cherish these moments as they grow too quickly! Props to you, Pop!

[Pem Tech]

Cray-ken...
I love it!!!

[thobin]

That is awesome!

TA

[UPscaler]

That is awesome! Can't wait to see some flight pictures!

My pink crayon has a motor hole in the plastic base...nothing else...I should fix that.


Braden

[Salvage-1]

It's all together and ready to go. Should be in the air sometime tomorrow.

If this flies well, I can always brazenly steal an idea and add 'squidly bits' to the nose cone.

[Pem Tech]

It's all together and ready to go. Should be in the air sometime tomorrow.

If this flies well, I can always brazenly steal an idea and add 'squidly bits' to the nose cone.

*nuk nuk nuk nuk*

[Sandy H.]

I'm not typically a fan of crayons or most tube fins (some I do like, but not all) but this rocket is cool.

Good one!

Sandy.

[Salvage-1]

Thanks for all the positive comments.

This project got to fly yesterday! First up was my yellow crayon. Straight boost, popped its top just after apogee and came down for a nice landing a few hundred yards away. When we walked the line down to the LCO table, we got quite a few comments on the rocket. I am a little amazed just how much attention it received. A few people lined the novel design of the fins, so i took the opportunity to mention that Pem Tech has a kit that is close to this one, and plugged it a bit.
I had a CTI Pro38 H225 with a 9 second delay. When it lit the crayon rose perfectly straight for an almost textbook boost through turnover and ejection. Ejection was bang on time. All this surprised me, and the people around, as the wind was around 15mph and most of the rockets were windcocking heavily. On the CrayonCam, you can see just how stable this is! Recovery was easy, I had stuffed it with a lime green 36" X Form, which brought it down nicely!

Wind was still nasty and so we packed up early and headed home again. More time was spent in the car traveling than actually spent at the launch. She loved it and wants to go back again!

[Pem Tech]

BRAVO!

[Salvage-1]

more pics