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. Aye aye! Begad! 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). Avast, ya bilge rat, me proud beauty! 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! Blimey! Also, I used a larger engine hook and an engine block made o' a heavy duty BT-50/BT-20 centerin' ring. Aye aye! Well, shiver me timbers, blow me down! Blimey! I changed t' engine hook t' accommodate t' larger engine. Avast, me proud beauty! Arrr! Blimey! After I glued t' first centerin' rin' in t' normal position (per instructions) with epoxy, matey, I used small strips o' thin plywood t' reinforce t' rings. These were on t' side o' t' centerin' rin' facin' t' front o' t' rocket. Aye aye! Begad! Blimey! 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. Arrr! Blimey! Lookin' back, ya bilge rat, it would have been easier and probably stronger t' make a new rin' out o' aircraft plywood. Avast, me proud beauty! Arrr! Blimey! Oh well. Ya scallywag! Ahoy! Blimey! 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. Begad! Another mistake that could be corrected. Aye aye! T' shock cord was tied t' t' t' t' upper centerin' rin' for strength. Begad! T' rin' was then glued on. T' fin was used t' show t' appropriate distance betwixt t' rings. Begad! Avast! Steel wool and another green centerin' rin' were added t' t' motor tube. Aye aye! Begad! 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. Begad! Usin' epoxy, I glued in t' fins. They were reinforced with hot glue. Avast! 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