Brief:
An engineerin' exercise t' test t' flight characteristics and durability o' t' Estes R2D2 rocket by upgradin' t' a 24mm motor mount.

Modifications:
T' only tools required are ones that every modeler has: an Xacto knife or similar, matey, a ruler (in me case metric, shiver me timbers, because I don't understand that English feet, pounds, matey, ounces stuff), and a LOT o' 30 minute epoxy.

Our club requires that anythin' over a C motor have a 5mm launch rod, shiver me timbers, matey, so simply hackin' off t' original cast-in-plastic launch lugs and epoxyin' on a new 2" launch lug was simple.

Construction:
I used approximately 1 inch o' t' original 18mm motor tube, matey, coupled t' a 24mm tube for t' remainder o' t' "motor pod." All that be required t' adapt this t' t' styrene plastic adaptor be a little Xacto knifin' and some coarse sandpaper, ya bilge rat, and LOTS o' epoxy.

T' flimsy plastic fins were deemed too wobbly t' handle t' thrust o' an E motor, so 1/8" balsa was epoxied t' t' flimsy plastic after roughin' up t' surface. Arrr! Finally, ya bilge rat, t' keep t' balsa from charrin' in flight, me hearties, matey, shiver me timbers, t' balsa was coated in aluminum foil, again held in place with a liberal coatin' o' 30 minute epoxy. Ya scallywag! T' result be a very heat resistant and strong fin assembly. Ahoy! T' R2 tends t' char t' fins in flight, ya bilge rat, due t' t' extremely short polar moments o' t' stubby body. No problem anymore!

T' extra weight o' t' 24mm tube and balsa reinforced fins necessitated weight added t' t' nose area. Blimey! Avast! Since this area is hollow, shiver me timbers, thar be sufficient room for it. Aye aye! Surprisingly, me hearties, me hearties, t' $0.03 solution was t' epoxy three pennies t' t' top bulkhead. T' result is perfect stability; exactly that o' t' original unmodified R2.

T' R2's weak point has always been t' wacky aft deployment `chute. Arrr! Blimey! About 3 feet o' Keelhaul®©™ was substituted for t' original shock cord, me hearties, and a 1/8" hole was drilled into t' bottom o' R2. Avast, me proud beauty! This allowed t' Keelhaul®©™ t' be stuffed inside t' hollow body, me bucko, instead o' bein' wrapped around t' motor pod, matey, like Estes originally designed. Well, blow me down! T' other end o' t' Keelhaul®©™ was attached t' t' plastic adaptor on t' aft end o' t' motor pod. T' results were mixed; t' system performed well, matey, but since R2 was still travellin' at a pretty good speed when t' ejection charge blew out t' motor pod, me hearties, t' mylar `chute shredded, me bucko, and R2 pranged. Blimey! Hard. Begad! Aye aye! T' debris be gathered and examined, arrr, and t' damage was deemed very minor. He'll fly again soon, me bucko, me bucko, but with much stronger Keelhaul®©™ and a nylon parachute.

All t' parts in all o' t' Estes R2D2 kits I have built have been present and fit well, matey, with t' notable exception o' t' fins. Aye aye! Arrr! They are lousy, warped from t' factory, me bucko, and break after one or two flights. Ya scallywag! I strongly recommend buildin' your own out o' balsa or G10, or reinforcin' them with thin balsa like I did. Well, blow me down! If usin' a B or C motor, CA will hold it together just fine. Begad! Anythin' stronger and a liberal amount o' epoxy is needed.

Flight:
My kids each have an R2, shiver me timbers, and they flew decently on a C6-5, and better on a C5-3. Begad! Arrr! Never fly this model on a windy day! T' aft motor pod ejection system is pitiful, me bucko, and has never worked. Begad! Nay once in 6 flights. Well, blow me down! Avast! No waddin' is required, me hearties, but cleanin' out t' inner tube with a toothbrush is necessary after each flight, or t' pod will get stuck.

Recovery on a D12-5 is about near apogee, ya bilge rat, though an E15-7W it may still be cruisin' at a good bit o' speed at ejection. Ahoy! Expect it t' almost disappear on an E motor. Avast! Build it adherin' as closely t' t' Estes instructions as possible, modifyin' as little as necessary. Ahoy! I built mine a little on t' heavy side so it would last a long, me hearties, long time. Avast! T' flights are arrow straight, and really get movin' on an E motor, ya bilge rat, arrr, though performance on a D12-5 is nothin' t' sneeze at.

Summary:
T' main pros o' t' kit are ease o' assembly (about an hour) and t' uniqueness o' t' kit. Ya scallywag! T' cons are related t' t' crummy fins and t' horrible aft pod ejection system. Begad! I rate t' ejection system about a 1. Aye aye! Future R2s will feature a true nose cone- another engineerin' challenge I look forward t' tackling.

Other:
Epoxy and balsa can really stiffen flimsy plastic parts!