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. 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. Aye aye! Blimey! T' schematics in Joe's post made it easy t' make t' new aft centerin' rin' and I used VCP t' print me templates. Blimey! Blimey! Blimey! Blimey! 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. Avast! Then I bent t' last 1/4" o' t' legs 90 degrees. Well, blow me down! 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, me hearties, 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. I also soaked t' fins with CA and sanded them down t' a streamlined shape. Avast, me proud beauty! Blimey! Arrr! Blimey! I probably won't use t' CA soakin' again as sandin' t' fins afterwards be 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. 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! 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. Arrr! Blimey! T' 1st flight was on a C11-5 and since I didn't use a motor hook, retention was accomplished by friction fit. Begad! Blimey! Begad! Blimey! I used a motor block, but it be positioned for t' E9. Blimey! Blimey! T' model took off and flew a stable flight path. Ejection was after apogee and t' model be pointed straight down. Avast! Blimey! No damage occurred on landing. Blimey! Blimey! For t' second flight I loaded an E9-6 and friction fit t' motor. Ya scallywag! Blimey! T' boost was fast and high, matey, arrr, t' rocket archin' over a bit before ejection. Avast, me proud beauty! Blimey! Because t' rocket was so small compared t' t' altitude, ya bilge rat, I thought it was goin' t' fly outside o' our launch site, me bucko, ya bilge rat, 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. T' streamers made for quick descents, matey, but with no damage. Arrr! 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. Begad! Definitely turned heads as I was buildin' it at club buildin' sessions. Blimey! Easily adapted t' other motor mounts.

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