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, I started t' booster by buildin' t' motor mount/center rings. Aye aye! Arrr! 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. Avast, me proud beauty! I then glued t' motor mount in place and attached t' fins just like on t' sustainer. Avast! I made a tube coupler usin' a 1 inch section o' t' remainin' BT, slit and overlapped t' fit inside t' BT-80. Blimey! This be glued t' t' top o' t' booster.

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

This is a fairly simple mod, me bucko, just takes some care in makin' sure your cuts are straight, matey, and t' booster's fins are securely glued. Ya scallywag! 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! I wanted a cool name for the two stager without havin' t' cut up t' decals too much. OY! look at that rocket! seemed like t' sentiment I be lookin' for. All I had t' fabricate be t' exclamation point, arrr, and that be pretty easy. Begad! Well, matey, blow me down! I didn't have any light blue paint for t' fins, ya bilge rat, shiver me timbers, me bucko, 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. I prepped by insertin' t' sustainer motor, securin' it down with a couple o' turns o' maskin' tape. I then taped t' booster motor t' it with scotch tape. 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). Blimey! Ahoy! They don't burn, shiver me timbers, me hearties, are light and fill BT's from 13mm on up and melt almost instantly when water hits them. Well, blow me down! Begad! I put about 7-8 in t' tube, folded t' chute on top o' them and set t' nose cone in place. Aye aye! T' shock cord be t' standard Estes paper mount and elastic that came with t' kit. Avast! I cut t' spill hole out o' t' supplied chute.. Ahoy! I didn't want too much drift. T' rocket left t' pad much like a standard Fat Boy, then arced over up wind slightly. Aye aye! Stagin' be clean and t' sustainer kept on headin' up and up wind. Begad! Ejection was good and t' rocket drifted back down close t' t' pad.

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