Crayon build - Posthumously

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gdjsky01

Kim's Rocketeer
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Yes this crayon is an ex-crayon, it has ceased to exist, gone to meet its maker, passed on, bereft of life, run down the curtain and joined the choir invisibile. :rofl:

But I thought I show how I built it anyway because, well, I can.

These pictures were taken over ten years ago! They are scans from who knows what and/or where. So bear with the size and quality, you'll get the idea.

Pic #1 Crayon bank, and lexan or polycarbonate, or acrylic sheet fins (you can see I had already done some work slotting.

Pic #2 Split the rear plastic tail cone for the four fins. The fin planform is shown in the another picture. Notice the centering ring and the two nuts. Both make a mechanical connection from the tail cone to the motor mount, and one can all have your retention clip.




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Sorry for the quality,

But now you can see the motor mount and the TTW acrylic fins. They have holes drilled in TTW tab near the root to let the Liquid Nails run through to the other side. The plastic wrap is to keep from scratching the fins now that the protective cover is off for gluing.

You can see the slots cut in the tail cone and the body tube to accomodate the fins. You may also see the countersunk, CA strengthened, holes on the side of the body tube for securing the tail cone to the body tube joint. It's right on the lowest black line.

Next terrible picture shows everything pretty much ready to assemble. You can see the bulkheads for the nose cone. One is small enough to get wedged in the inner lip of the nose cone the other fits over the end of the shoulder, but is small enough to fit in the body tube. Drawn together by an eyebolt they jam, and stay put. That said, I never attached the chute to the eyebolt, always to a loop in the bungie cord (yes bungie cord).

The last tiny picture shows the tube slots and countersunk holes.


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Crayon29-TubeSlots.jpg
 
So for the finale, I have nothing. Back then I think all the pictures I had were scans of photos, or came on Kodak Picture disks.

So words will have to do.

1) Slide the mount mount/fin assembly up into the tube and into the slots in the tube
2) Line up the holes on the plastic tail cone with the tee nuts on the bottom centering ring and slide the tail cone on. Screw the tail cone to the rear centering ring, and use short stubby wood/machine screws to lightly secure (in those countersunk holes in the body tube) the tail cone lip to the rear of the tube. This will hold using 29mm H's for sure.

You were pretty much read to go. I used a LOC style shockcord mount.

And you'd break fins. Right at the tube. :no::y::mad: With 36 inch (91cm) chute it made no difference. Even a 48 could not assure no breakage. Not with hard playa and any horizontal drift component.


 
So after replacing two or three fins, I got an idea. One per decade; That must have been the one for the 90's.

I bolted an eyebolt (cause what else would you do with an eyebolt) to the rear of the tailcone, through the aft centering ring.

Take a look at exhibit one. You can see the bungie peeking out from the bottom right and top left. It entering the tube through a deep slot cut in the upper lip of the nose cone. At ejection the body hung from the shock cord upside down. (You can also see one of the four machine / wood screws at the base of the tube. Those draw the tail cone lip flush to the tube.)

Now the first thing to hit the ground was the upper body tube and not the fins! That cut down fin breakage to almost nil! No one cared as you could barely see it from a distance. The cord ran the same side as the launch lugs not the side that face the crowd. So I had the look I wanted (no fins), without having to make a new fin every @%#% flight!

The End.


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:clap: Very nice Show and Tell. My sister stopped a DT for me.Picked up 6 more of them thar little crayons.
 
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