Modification - Two-Stage Fat Boy

Modification Two-Stage Fat Boy Modification

Modification - Two-Stage Fat Boy

Contributed by Kevin Johnson

Manufacturer:

Brief:
Kit bashed two Fat Boys into one two-stage rocket.

Modifications:
After buildin' t' sustainer per t' instructions, ya bilge rat, me hearties, I started t' booster by buildin' t' motor mount/center rings. Begad! Usin' t' completed mount as a guide, I marked t' aft end o' t' second BT and cut it down just in front o' t' fin slots. Arrr! Arrr! I then glued t' motor mount in place and attached t' fins just like on t' sustainer. Arrr! I made a tube coupler usin' a 1 inch section o' t' remainin' BT, slit and overlapped t' fit inside t' BT-80. Avast! Blimey! This was glued t' t' top o' t' booster.

Construction:
Sustainer is a regular Fat Boy built t' t' plans, minus t' engine hook. T' booster be t' fin can and motor mount from t' second kit.

This is a fairly simple mod, ya bilge rat, just takes some care in makin' sure your cuts are straight, matey, and t' booster's fins are securely glued. You want t' make sure that t' sustainer's motor sticks out at least 1/2 inch if you use an engine block for good contact with t' booster motor for staging. Aye aye! Ahoy! I wanted a cool name for the two stager without havin' t' cut up t' decals too much. Begad! OY! look at that rocket! seemed like t' sentiment I was lookin' for. Well, blow me down! All I had t' fabricate was t' exclamation point, and that be pretty easy. I didn't have any light blue paint for t' fins, matey, arrr, but t' fluorescent yellow makes a nice contrast t' t' stock fin decals.

Flight:
I probably should have thought a little more about t' stagin' and used a 24mm mount for D12-0 grunt off t' pad, but t' boost looked ok (if a little off vertical) with a C6-0. Well, blow me down! I prepped by insertin' t' sustainer motor, securin' it down with a couple o' turns o' maskin' tape. Aye aye! I then taped t' booster motor t' it with scotch tape. Aye aye! Then I slid t' booster section over t' motors and taped t' overhangin' motor t' t' booster's motor tube. Aye aye! I have started t' use t' biodegradable packin' peanuts made o' corn starch for recovery waddin' (cause ran out o' t' normal stuff! it worked very well on me test flights). Ahoy! They don't burn, are light and fill BT's from 13mm on up and melt almost instantly when water hits them. Begad! Well, blow me down! I put about 7-8 in t' tube, arrr, folded t' chute on top o' them and set t' nose cone in place. Avast! T' shock cord was t' standard Estes paper mount and elastic that came with t' kit. Begad! Well, me hearties, blow me down! I cut t' spill hole out o' t' supplied chute.. Avast, me proud beauty! I didn't want too much drift. T' rocket left t' pad much like a standard Fat Boy, then arced over up wind slightly. Begad! Stagin' be clean and t' sustainer kept on headin' up and up wind. Ejection be good and t' rocket drifted back down close t' t' pad.

Summary:
This is a pretty easy mod. Begad! I guess t' con is that I had t' use 2 kits t' get 1 rocket, me bucko, shiver me timbers, but what t' heck.. Blimey! Avast, me proud beauty! it was fun. Blimey! Might consider makin' t' booster a 24 mm mount for more thrust on lift off.