I've been itching to build a "tuffie", so I slit open a FlisKits Alien8.

As with all other Flis Kits I've built the fins have to be cut out from 3/32" balsa (no problem, its better than "die crushed".)

The kit is complete and all parts are perfect. The instructions are nice, and with a little bit of humor hear and there.

I'll knock out the engine mount first.

Because I can't help myself, I deviated slightly from the instructions and added a Mylar EH retainer--instead of using tape. When I'm never going to see a component again (except under the worse of circumstances) I always try to over-engineer it.

Now for some technique: the solid (non-slotted ) 50/20 CR is very tight on the BT20, so rather than sanding or delaminating the ID, I press the CR down on a "mandrel" that is the scrap piece of an Apogee PNC80 nose cone that I had cut to make a V2 boattail long ago. I actually use this VERY often. Just a couple of pushes and twists is all it takes to size the ID of almost any CR.

In another deviation from the instructions, I've attached the Kevlar shock cord leader to the engine mount instead of to the coupler at the top of the bottom BT. This makes it a lot easier to "hook" the Kevlar from inside the engine mount if the elastic shock cord needs replacing.

TBC

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__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

Now to fabricate the (3) ping pong balls. The last time I built a rocket that had a ping pong ball was a Custom P.O.N.G. (the fantasy-fleet rocket that resembles the spaceship from the "Josie and the Pussycats in Outer Space" cartoons.)

All of the balls have a defined equatorial seam. I pencil a line around each ball on the seam. I then center a very short piece of BT50 at the "pole" and adjust it until the distance to the equatorial line appears the same all around. I then draw a line around the BT50 and verify the spacing at several points with a dressmaker's tape. I then make a circle on the other "pole" of the same ball and on the "poles" of the other (2) balls.

Hey! Wake up! This gets better! (or not)

Now for the cut. USING A FRESH #11 BLADE I make several passes around the polar circle of the ball until I feel the blade insert itself into the ball's interior. I then apply pressure on the cut with my thumb and this causes the cut to "run" like scored glass and the divet pops right out. I repeat the same cut for all (3) balls and then sand the ID's of the cuts gradually until a BT50 just passes through.

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__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

and........Voila!

TBC

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__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

After marking the BT50, gluing the engine mount into it, and cutting out the balsa fins from the supplied patterns, I use Titebond Red label to attach the #4 fins to the BT50. Before the adhesive hardens I lay the assembly down onto the fin alignment jig where it will remain until the adhesive is completely set.

TBC

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__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

Now the fin #1 and pod assembly is glued onto the corresponding line.

TBC

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__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

All of the lower fins are now glued on.

The next steps involve placing the ping pong balls onto this same BT and I won't be doing that until the lower fins are epoxy filletted.................

..............tomorrow.

Time for a Scotch and an IPA. Good night. TBC

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__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

Jeff, could you tell me what the length's are of the BT50 tubes? I have an original I'd like to build, but it's missing them. Thanks!

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www.wooshrocketry.org NAR Sec. 558
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unstable by design

18", 18", and 4".

__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

The balsa fins are now filletted with epoxy. The first prepped ping pong ball is tacked in place.

To prepare the "hoop" for attachment, I first sand the ash from the root edges using the Corain slab covered with 220 and slightly round the outer edges by hand.

After attaching the "hoop" with Titebond, I make up a totally ugly yet functional brace from long pieces of absolutely flat 1/8" balsa scrap and clothespins.

Laugh if you want--but it works like a charm!

After the Titebond has dried on the "hoop" and the first ball I fillet them with epoxy. It looks like the worst is over!

I have to leave right now and take care of a "situation" in Birmingham, AL.

TBC

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__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

JJ,

I get an invalid attachment message when I click on the last batch of pic's.

Never mind, they are working now, IDK?

Nice build.

__________________
If it flies, I can crash it!