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, a ruler (in me case metric, me bucko, because I don't understand that English feet, me bucko, matey, arrr, 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, 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, shiver me timbers, arrr, ya bilge rat, coupled t' a 24mm tube for t' remainder o' t' "motor pod." All that was required t' adapt this t' t' styrene plastic adaptor be a little Xacto knifin' and some coarse sandpaper, 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! Avast, me proud beauty! Finally, t' keep t' balsa from charrin' in flight, arrr, t' balsa be coated in aluminum foil, arrr, again held in place with a liberal coatin' o' 30 minute epoxy. Avast! T' result was a very heat resistant and strong fin assembly. T' R2 tends t' char t' fins in flight, 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. Since this area is hollow, thar be sufficient room for it. Aye aye! Avast, me proud beauty! Surprisingly, shiver me timbers, t' $0.03 solution be t' epoxy three pennies t' t' top bulkhead. Blimey! 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. About 3 feet o' Keelhaul®©™ was substituted for t' original shock cord, and a 1/8" hole was drilled into t' bottom o' R2. Avast! This allowed t' Keelhaul®©™ t' be stuffed inside t' hollow body, shiver me timbers, instead o' bein' wrapped around t' motor pod, like Estes originally designed. Well, blow me down! Avast, me proud beauty! T' other end o' t' Keelhaul®©™ be attached t' t' plastic adaptor on t' aft end o' t' motor pod. Begad! T' results were mixed; t' system performed well, matey, but since R2 be still travellin' at a pretty good speed when t' ejection charge blew out t' motor pod, t' mylar `chute shredded, and R2 pranged. Arrr! Hard. Ya scallywag! T' debris was gathered and examined, me hearties, and t' damage be deemed very minor. Begad! Ahoy! He'll fly again soon, ya bilge rat, 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, with t' notable exception o' t' fins. Ahoy! Begad! They are lousy, warped from t' factory, and break after one or two flights. Begad! I strongly recommend buildin' your own out o' balsa or G10, or reinforcin' them with thin balsa like I did. Avast! If usin' a B or C motor, arrr, CA will hold it together just fine. Anythin' stronger and a liberal amount o' epoxy is needed.

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

Recovery on a D12-5 is about near apogee, though an E15-7W it may still be cruisin' at a good bit o' speed at ejection. Blimey! Ahoy! Expect it t' almost disappear on an E motor. Well, blow me down! Build it adherin' as closely t' t' Estes instructions as possible, modifyin' as little as necessary. Begad! Aye aye! I built mine a little on t' heavy side so it would last a long, long time. T' flights are arrow straight, and really get movin' on an E motor, me bucko, 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. Begad! T' cons are related t' t' crummy fins and t' horrible aft pod ejection system. Begad! I rate t' ejection system about a 1. Arrr! 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!