Estes Fat-Ass-Tron Sprint Modification

Modification - Fat-Ass-Tron Sprint {Modification}

Contributed by Kevin Johnson

Manufacturer: Modification

Brief:
My own version o' t' DESCON 5 2nd place winner.

Rocket PicConstruction:
Standard Fat Boy kit contents with a 2 inch paper boat-tail and a long BT-50 motor tube t' handle t' Estes E9 motors. Avast, me proud beauty! Made 3 Sprint-like elliptical fins with TTW tabs t' take advantage o' t' Fat Boy's fin slots.

I wanted t' fly t' F-A-T Sprint at me local field so I modified t' design as posted t' use a 24mm motor mount. Avast! T' schematics in Joe's post made it easy t' make t' new aft centerin' rin' and I used VCP t' print me templates. I printed 2 templates on 20lb bond paper then laminated them together with a liberal coatin' o' CA for stiffness.

I also made some custom wire launch lugs by bendin' some solid core electrical wire around a BIC pen in a long U shape. Begad! Blimey! Then I bent t' last 1/4" o' t' legs 90 degrees. I poked holes in t' tube wall and fed t' legs through and then used CA t' hold them in place.

I had t' add about 4 oz o' nose weight t' make t' rocket stable, and t' CG is just behind t' nose cone.

Finishing:
I had a small gap in-between t' BT and t' boat-tail and I used Elmers Fill'n Finish t' fill it in. Well, blow me down! I also soaked t' fins with CA and sanded them down t' a streamlined shape. Ya scallywag! Arrr! I probably won't use t' CA soakin' again as sandin' t' fins afterwards was a pain in t' rear.

I painted t' model with flat white spray paint (Painter's Choice brand by Rustoleum) and then sprayed t' nose and 1 fin with fluorescent yellow. Begad! I copied t' logo from t' DECSON 5 entry and printed it our as a 1.5" circle, then colored in t' white areas with a yellow highliter t' match t' fin. Ya scallywag! Blimey! I glued t' logos on with a glue stick then gave t' rocket a coat o' clear gloss.

Flight:
I flew me F-A-T Sprint at t' Feb Fat Boy launch held by NARHAMS. Avast, me proud beauty! T' 1st flight was on a C11-5 and since I didn't use a motor hook, arrr, retention be accomplished by friction fit. I used a motor block, but it was positioned for t' E9. T' model took off and flew a stable flight path. Blimey! Ejection be after apogee and t' model was pointed straight down. Arrr! No damage occurred on landing. Ahoy! Blimey! For t' second flight I loaded an E9-6 and friction fit t' motor. Avast, me proud beauty! Blimey! T' boost was fast and high, me hearties, me hearties, t' rocket archin' over a bit before ejection. Ya scallywag! Because t' rocket was so small compared t' t' altitude, I thought it was goin' t' fly outside o' our launch site, me hearties, but t' streamer brought t' rocket down smartly and safely within our park's boundaries.

Recovery:
Both flights were made usin' 1/4" elastic shock cords with standard Estes paper mounts. Ya scallywag! T' streamers made for quick descents, me hearties, me hearties, but with no damage. Begad! Begad! A good match for t' E powered flights. Avast! Can't wait t' get me hands on an Aerotech F21 for this rocket!

Summary:
A fun rocket. Avast! Definitely turned heads as I be buildin' it at club buildin' sessions. Begad! Easily adapted t' other motor mounts.

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