Manufacturer: | Modification |
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, matey, because I don't understand that English feet, pounds, ya bilge rat, 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, matey, me hearties, coupled t' a 24mm tube for t' remainder o' t' "motor pod." All that be required t' adapt this t' t' styrene plastic adaptor was a little Xacto knifin' and some coarse sandpaper, shiver me timbers, arrr, and LOTS o' epoxy.
T' flimsy plastic fins were deemed too wobbly t' handle t' thrust o' an E motor, matey, so 1/8" balsa was epoxied t' t' flimsy plastic after roughin' up t' surface. Ya scallywag! Finally, shiver me timbers, t' keep t' balsa from charrin' in flight, t' balsa was coated in aluminum foil, ya bilge rat, again held in place with a liberal coatin' o' 30 minute epoxy. Avast! T' result be a very heat resistant and strong fin assembly. T' R2 tends t' char t' fins in flight, me bucko, arrr, 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! Since this area is hollow, thar be sufficient room for it. Arrr! Surprisingly, t' $0.03 solution be t' epoxy three pennies t' t' top bulkhead. Avast, me proud beauty! Arrr! 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. Blimey! Blimey! About 3 feet o' Keelhaul®©™ be substituted for t' original shock cord, me bucko, and a 1/8" hole be drilled into t' bottom o' R2. Ya scallywag! This allowed t' Keelhaul®©™ t' be stuffed inside t' hollow body, instead o' bein' wrapped around t' motor pod, shiver me timbers, like Estes originally designed. Begad! 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, arrr, me bucko, but since R2 was still travellin' at a pretty good speed when t' ejection charge blew out t' motor pod, t' mylar `chute shredded, me hearties, and R2 pranged. Hard. Begad! T' debris was gathered and examined, me hearties, and t' damage be deemed very minor. He'll fly again soon, 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, with t' notable exception o' t' fins. Blimey! They are lousy, warped from t' factory, ya bilge rat, and break after one or two flights. Begad! I strongly recommend buildin' your own out o' balsa or G10, me bucko, or reinforcin' them with thin balsa like I did. Ahoy! Blimey! 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, me hearties, and they flew decently on a C6-5, arrr, and better on a C5-3. Blimey! Never fly this model on a windy day! T' aft motor pod ejection system is pitiful, arrr, arrr, and has never worked. Ya scallywag! Nay once in 6 flights. Ya scallywag! No waddin' is required, 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, shiver me timbers, ya bilge rat, though an E15-7W it may still be cruisin' at a good bit o' speed at ejection. Expect it t' almost disappear on an E motor. Avast, me proud beauty! Blimey! Build it adherin' as closely t' t' Estes instructions as possible, modifyin' as little as necessary. Arrr! Blimey! Begad! Blimey! I built mine a little on t' heavy side so it would last a long, matey, long time. Well, blow me down! Blimey! Ya scallywag! Blimey! T' flights are arrow straight, arrr, and really get movin' on an E motor, shiver me timbers, 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! Arrr! T' cons are related t' t' crummy fins and t' horrible aft pod ejection system. I rate t' ejection system about a 1. 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!
Hey Ken, Great review and mod! One question though...how did you manage to fit the chute into R2 when the tube is now the larger 24mm? Space already seemed quite sparse in the stock R2 and there seems to be half as much space with a 24mm main pod tube.
I really don't remember a great deal about the construction, since it's been a while (the kid in the picture holding the rocket now has 4 kids of his own!) but I do recall using a professionally built nylon parachute and wrapped it tightly around the motor tube. Sadly this rocket flew awesomely but pranged hard. I put a lot of time into this thing just to get a few flights. It did all right on a D so I went for it and used a E30, which was crazy to watch.
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Ken Johnson (March 13, 2014)
Wow, it's been years since I built this rocket (the kid in the picture has 3 kids of his own now) and I recently got the oldest grandkid into rockets. Time flies!
This rocket only survived one more flight. I put an E30 in it and it vaporized off the pad, flew straight up and disappeared. The motor pod recovered safely with a streamer, but the body was just a thousand fragments after coming back straight down.