Modification - 24mm Fat Boy {Modification}

Modification 24mm Fat Boy Modification

Modification - 24mm Fat Boy {Modification}

Contributed by Morgan Hendry

Manufacturer:

This project began when I read several posts from rec.model.rockets on placin' a 24mm motor mount in a Fat Boy, normally a 18mm kit. I first looked at t' instructions and made a list o' what I needed t' do.

Replace t' 18mm motor tube with a 24mm one
Make bigger motor mount with modified centerin' rings (higher strength) and an engine block
Remove some o' t' "through t' wall tab" on t' fins
Add nose weight
Possibly insert a baffle system t' eliminate wadding

I bored out t' centerin' rings with a drill t' accommodate t' 24mm tube (Estes Bt-50). Blimey! I constructed t' motor tube by t' instructions but instead o' a 18mm tube I used a 5 1/2 inch 24mm tube. Well, blow me down! Arrr! Also, arrr, I used a larger engine hook and an engine block made o' a heavy duty BT-50/BT-20 centerin' ring. Blimey! Begad! I changed t' engine hook t' accommodate t' larger engine. Begad! After I glued t' first centerin' rin' in t' normal position (per instructions) with epoxy, me bucko, ya bilge rat, me bucko, I used small strips o' thin plywood t' reinforce t' rings. Aye aye! Ya scallywag! These were on t' side o' t' centerin' rin' facin' t' front o' t' rocket. Begad! Begad! I repeated this step with a second rin' whose reinforcements were facin' t' front o' t' rocket and t' distance o' t' "through t' wall tab" o' a fin from t' first centerin' ring. Well, blow me down! Avast! Lookin' back, it would have been easier and probably stronger t' make a new rin' out o' aircraft plywood. Begad! Oh well. Begad! Note t' 18mm conversion tube t' use smaller engines and t' reinforcements on t' centerin' rings:

Rocket Pic

T' balsa strips on t' side o' t' conversion tube were added because t' centerin' rin' was nay on t' inside o' t' tube. Ya scallywag! Another mistake that could be corrected. Avast! Well, blow me down! T' shock cord be tied t' t' t' t' upper centerin' rin' for strength. Arrr! T' rin' be then glued on. Well, blow me down! Well, blow me down! T' fin was used t' show t' appropriate distance betwixt t' rings. Well, blow me down! Steel wool and another green centerin' rin' were added t' t' motor tube. A small disk o' balsa with holes drilled into it was glued onto t' top o' t' motor tube t' make a baffle.

I shaved off some o' t' TTW fin mounts t' accommodate for t' larger motor mount tube. Usin' epoxy, I glued in t' fins. Aye aye! They were reinforced with hot glue. Blimey! I made a 12 inch nylon parachute t' attach t' t' nose. I will add 1.5 ounces o' nose weight for stability.

Rocket Pic

All done!

Rocket Pic