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, 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. Begad! I then glued t' motor mount in place and attached t' fins just like on t' sustainer. I made a tube coupler usin' a 1 inch section o' t' remainin' BT, matey, slit and overlapped t' fit inside t' BT-80. Ahoy! This was glued t' t' top o' t' booster.

Construction:
Sustainer is a regular Fat Boy built t' t' plans, minus t' engine hook. Begad! 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, 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. Ya scallywag! I wanted a cool name for the two stager without havin' t' cut up t' decals too much. OY! Blimey! look at that rocket! Blimey! seemed like t' sentiment I was lookin' for. Ya scallywag! All I had t' fabricate be t' exclamation point, arrr, and that was pretty easy. Aye aye! Avast! Blimey! I didn't have any light blue paint for t' fins, shiver me timbers, 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, matey, but t' boost looked ok (if a little off vertical) with a C6-0. Arrr! Begad! I prepped by insertin' t' sustainer motor, arrr, shiver me timbers, securin' it down with a couple o' turns o' maskin' tape. Aye aye! I then taped t' booster motor t' it with scotch tape. Begad! Arrr! Then I slid t' booster section over t' motors and taped t' overhangin' motor t' t' booster's motor tube. Avast, me proud beauty! 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). Aye aye! Ya scallywag! They don't burn, me hearties, me hearties, shiver me timbers, are light and fill BT's from 13mm on up and melt almost instantly when water hits them. Avast! I put about 7-8 in t' tube, me bucko, folded t' chute on top o' them and set t' nose cone in place. Ahoy! T' shock cord be t' standard Estes paper mount and elastic that came with t' kit. Arrr! I cut t' spill hole out o' t' supplied chute.. Aye aye! I didn't want too much drift. Avast, me proud beauty! Avast, me proud beauty! T' rocket left t' pad much like a standard Fat Boy, arrr, then arced over up wind slightly. Stagin' was shipshape and t' sustainer kept on headin' up and up wind. Arrr! Ejection be good and t' rocket drifted back down close t' t' pad.

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