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, 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. Begad! I then glued t' motor mount in place and attached t' fins just like on t' sustainer. Avast! Blimey! I made a tube coupler usin' a 1 inch section o' t' remainin' BT, slit and overlapped t' fit inside t' BT-80. Arrr! 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, just takes some care in makin' sure your cuts are straight, shiver me timbers, 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. Begad! I wanted a cool name for the two stager without havin' t' cut up t' decals too much. Avast, me proud beauty! OY! look at that rocket! seemed like t' sentiment I was lookin' for. All I had t' fabricate was t' exclamation point, shiver me timbers, and that be pretty easy. Arrr! Avast, me proud beauty! I didn't have any light blue paint for t' fins, 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, shiver me timbers, 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. Avast! 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. Avast, me proud beauty! Arrr! 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! They don't burn, matey, shiver me timbers, are light and fill BT's from 13mm on up and melt almost instantly when water hits them. Well, blow me down! Arrr! I put about 7-8 in t' tube, folded t' chute on top o' them and set t' nose cone in place. Ahoy! T' shock cord was t' standard Estes paper mount and elastic that came with t' kit. Avast! I cut t' spill hole out o' t' supplied chute.. Aye aye! I didn't want too much drift. Avast, arrr, me proud beauty! T' rocket left t' pad much like a standard Fat Boy, arrr, then arced over up wind slightly. Begad! Stagin' be shipshape and t' sustainer kept on headin' up and up wind. Avast, me proud beauty! Begad! Ejection was good and t' rocket drifted back down close t' t' pad.

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