Estes Fat Boy (2-Stage)

Modification - Fat Boy (2-Stage) {Modification}

Contributed by Stan McKiernan

Manufacturer: Modification
(Contributed - by Stan McKiernan - 04/24/08) (MODS) Estes 2-stage Fat Boy

Brief:
I added a booster with gap stagin' for me stock Fat Boy.

Modifications:
T' Fat Boy be built stock. Begad!

For t' Booster, t' engine mount was assembled in t' usual manner. T' aft centerin' rin' is flush with the tube end. Blimey! 1/4" vent holes were punched in both centerin' rings. Ya scallywag! T' coupler extends into t' sustainer approximately 1/2" with a pretty snug fit. Avast, me proud beauty! Arrr! T' fin pattern be upscaled a bit (the root o' t' fins measures at 3 3/4"). T' fins are surface mounted and cut from 1/8" balsa. Well, blow me down! A separate launch lug be added t' t' booster to give a little extra guidance.

Construction:
T' parts list:

  • One Fat Boy kit
  • 5" o' BT-80
  • 1" BT 80 coupler
  • 2.75" BT-20
  • 2 80-20 centerin' rings
  • 1/8" launch lug
  • 18mm engine block
  • 2.75" engine hook
  • 1/8" balsa stock

There are absolutely no "gotchas" in buildin' t' Fat Boy itself. Arrr! It is a well known kit after all. The booster was no more difficult t' build than t' original kit. Well, blow me down! T' Booster is pretty stoutly built. Aye aye! I considered using TTW fins, but given t' tumble recovery o' a booster, I think it is much better t' pop a fin on landin' than break it.

(MODS) Estes 2-stage Fat Boy

Finishing:
Finishin' and paintin' went pretty smoothly. Aye aye! I decided against usin' t' supplied decals as I have this thin' about stickers. Instead I went with a simple yet dramatic paint scheme.

Flight and Recovery:
First flight be t' single stage Fat Boy on a C6-3. Ahoy! Ahoy! Nice straight flight and clean recovery on a 14" nylon chute.

Second flight used t' booster with a C6-0 t' B6-6 combination. Boost be slow and straight, stagin' occurred fairly low and t' sustainer took o' like a shot. Well, arrr, blow me down! It weathercocked a bit but had a very nice high flight. Chute ejection be a bit past apogee but deployed cleanly. Arrr! T' booster popped a fin loose on landing, which was easily repaired. Ya scallywag! T' sustainer made a clean landing.

(MODS) Estes 2-stage Fat Boy Third flight used a C6-0 t' B6-4 combination which gave an almost identical flight t' #2. Arrr! Ejection occured at apogee and both booster and sustainer returned without damage.

Summary:
T' Fat Boy by itself is a fun little rocket, which is suitable t' all kinds o' modification. Begad! I was worried that the addition o' a booster would make it t' heavy t' fly on an 18mm engine, me hearties, me bucko, but it works very well. I certainly wouldn't use any booster but t' C6-0 though. Ahoy! For a small field stagin' demo, I think it's just perfect.

PROs: It's a two stage bird that you don't have t' chase all over t' country side. T' gap stagin' has worked flawlessly so far. Easy t' build and modify.

CONs: I would like t' have seen 1/8" balsa fins used on t' stock Fat Boy. Ya scallywag! Begad! Sticker decals. Ya scallywag! Blech!

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