Not being a big Star Wars fan, I would not have sought out an R2D2 model rocket kit. However, my family loves it, and got me an Estes Fifteenth Anniversary R2D2 for Father's Day 1999.
This is sort of a goofy rocket, but not completely absurd: R2D2 did fly on occasion in the movies. And, folks, I've had so much fun with this thing that I just had to write about it.
The 15th Anniversary R2D2 is a reissue of the biggest one they ever made, based on the 4" BT-101 body tube. It features a printed body wrap, lots of blow-molded and/or vacuum-formed white styrene parts, and injection-molded clear styrene fins for flight. (They're in place in the above photo, believe it or not.) It's designed to use a single C6-3 motor (more on that later) and has an 18" printed plastic parachute, standard Estes style.
Assembly was not difficult, with one possible exception. Others have reported that the body wrap didn't fit too well, and my experience was that it's a fraction of an inch too short. In addition, the adhesive is very permanent: once it touches the tube, it's there for the duration. In my case, I got it on a bit crooked, as you can see in the picture. Finishing required blue, silver, and black paint; I used blue in place of black for R2's "eye," which was a mistake.
This thing has been engineered to "just barely fly," so on many counts, it's a good idea to follow instructions exactly. Two areas of special concern: (1) the instructions are very explicit about the attachment of the parachute near the base end of the shock cord. That seemed unbelievable but it is right. (2) Those big, thick paper centering rings are stronger than they look, but be sure to glue them very firmly to the outer body tube. Their only likely failure point is to fold into a cone and pull away from the BT-101.
I made two subtle mods. I replaced the shock cord with a better quality elastic (and a foot longer at that) and I increased the nose weight slightly because I was advised that R2 is none too stable and sometimes hangs a left. I would have liked to replace the questionable recovery wadding arrangement with a Nomex shield, but in fact it worked.
That nose weight was interesting to begin with. The kit includes three of the lead disks I remembered from 1966-era kits and haven't otherwise seen since. I kept them, and replaced them with a coil of lead wire that totaled just a few grams more. In retrospect, I think the designers deliberately used the least they could justify in order to bring the thing up to minimum performance with a C6-3.
One clear plastic fin unit in my model was warped to the point that I would have been justified to return it. I solved the problem in a way not for the weak of heart: I heated it by holding it 2" from a red hot electric range burner and gently bending it back into shape. This worked, but I knew it would have been easy to (1) burn myself, or (2) watch the thing droop irreversibly onto the hot burner.
The package card lists C6-3, C5-3, and B6-2 as recommended engines. The instruction sheet says "C6-3 only." It took a while to understand why. The instruction sheet is an edit from the original, which was issued before C5-3 or B6-2 were available from Estes. However, the B6-2 would never have been enough motor for this beast. The package card was probably printed before production kits were tested, suggesting that the prototypes had some lighter parts.
My R2's first flight was perfectly straight, very slow, not very high, and once up there, it headed for the ground like a homesick rock. The ejection charge went off halfway down. The parachute opened fully just about 15 feet off the ground. One of the clear plastic fins was broken. For the first of several times, I resolved that R2 had seen its air time and would be retired to the bookshelf where it now resides. Testor's Cement for Plastic Models healed the fin unit, but it could no longer be considered invisible.
But I couldn't resist trying to cluster it. I had used a pair of A10's to supplement C and D motors before, and there was room, so it seemed like the thing to do. Cutting openings on either side of the motor mount tube, I glued in a pair of BT-5 tubes. One had to be slotted to allow for the C6's motor hook. The C6 went in first, then the A10-3's. The A10's would be allowed to eject themselves. When I was happy with it, out we went to launch.
All three motors fired, and the flight was much stronger than the first. The added power did seem to be just what R2 needed. But if the first flight was a heart-stopper, the second carried a hint of caution. Near the end of the burn, it hung a 30 and headed south. Fortunately, it was well off the ground, and ended up ejecting and fully opening the parachute at apogee. I considered this a much better flight, but even so, it broke the clear plastic fins on landing. More Testor's.
Meanwhile, I realized what the mid-course correction meant. One of the A10's had burned out before the other, and had given R2 a good dose of rotation, because they're right alongside the CG. I was concerned that it could be more serious, and decided not to recommend this modification. Once again, R2 was declared retired and placed on the shelf. But I couldn't resist flying it at our club meet in September.
This time, one motor lit far enough ahead of the other so that the thrust curves were not at all in synch. R2 wandered all over the sky in front of the LCO's table, ejected both A10's in different directions, and finally bit the dust at the very moment of ejection. Dome in the dirt, he jumped another six to ten feet and rolled like a bad punt. There was a gasp from the crowd followed by gleeful laughter. A fellow flyer helped me find the many pieces of clear plastic that had been R2's fin unit. In addition, a leg was peeled off the body, and the leading edge of the body tube separated a couple of inches along the spiral groove. Repairs were not too difficult, btw.
So, folks, let it be known: I do not recommend this cluster arrangement. I do recommend more power if it can be had.. In retrospect the proper modification would be a BT-50 motor tube to use a D12-3.
Mine will fly again with an Aerotech 18mm D composite, at some unspecified future date. The motor is exactly on the CG, so there is no worry about stability changes with added motor weight. I do think that the added weight of the extra motor mount tubes makes single C6-3 flight very iffy for mine now. The clear plastic fin unit has a nice decorative crackle effect throughout, but it seems serviceable.
This kit sat in the store for several years, and might be scarce now. That said, some may say it's a collector's piece and I'm a fool to fly it. Nonsense.
This is a model rocket. Its printed wraps are a compromise to light weight to allow flight; they are not as detailed or as contoured as a plastic body could be for shelf display. You get the feeling that some engineer spent some up close and personal time with the prototype before this one was kitted, working out the details so it could possibly fly. Does that still happen at Estes Industries? This model (and the designer's work) is completed by flight, just as a Saturn V would be.