Building the Estes Xarconian Cruiser (part 2)

I’ve never been particularly careful about paying attention to weight during a build (mine or the kit’s); this time I think I’ll try going to the other extreme. I weighed all the parts in the kit, as well as the parts I intend to use instead of some of the kit parts. As mentioned before, I’ll be redshifting this with a 24 mm motor mount; I’ll also use a Kevlar + braided elastic shock cord instead of the supplied rubber band. (Probably 1/4″ elastic, but I don’t have enough, so I weighed a piece of 1/2″ elastic for the heck of it.)

And I doubt I’ll ever launch this on an Estes plastic parachute.

I didn’t want to cut the 2055 centering rings or the fins out of their respective sheets, so I weighed the whole sheets. I also weighed the decal sheets. The centering rings don’t matter much; I’m not using them. The fins will get weighed on their own later. The decals, well, probably not much of a weight factor… though in principle I can deduct the weights of the scraps and backings when I’m done to figure out what their weight is.

To weigh the 24 mm motor mount, first I had to cut a piece of the right length. That marked the start of actual construction, I suppose. I made it 2 3/4″ long so I won’t be tempted to try launching this on an E. Well, not a black powder E.

Xarconian Cruiser [Estes #3223]
Weights (ea) at outset
Included kit parts qty (g) (oz) Notes
Engine mount tube (18 mm) 1 1.3 0.05 To be replaced w/ 24 mm
Card containing both centering rings 1 2.6 0.09 Rings are probably about 1/3 of card weight. To be replaced w/ 5055
Mylar engine hook retainer ring (19 mm) 1 0.2 0.01 Not used (Kapton tape instead)
Engine hook 1 1.4 0.05
Engine block 1 0.3 0.01 To be replaced w/ 24 mm
Tail cone 1 3.8 0.13
BT55 body tube 1 21.9 0.77
1090 body tube 2 13.9 0.49
Wood dowel 1 0.3 0.01
Balsa sheet, fins J-L 1 15.6 0.55
Balsa sheet, fins M-O, S-T 1 7.4 0.26
Balsa sheet, fins P-Q, U 1 5.5 0.19
Plastic nose cone 1 15.8 0.56
Launch lug 1 0.2 0.01
Shock cord 1 4.4 0.16 To be replaced w/ Kevlar + elastic
Parachute 1 7.4 0.26 To be replaced on per flight basis (e.g. Top Flight chute + snap swivel)
Waterslide decals (large sheet) 1 6.8 0.24
Waterslide decals (small sheet) 1 5.5 0.19
Additional parts
Engine mount tube (24 mm) 1 1.7 0.06
Centering ring (5055) 2 0.3 0.01
Engine block 1 0.7 0.02
Kevlar (36″) 1 0.3 0.01
Elastic (1/2″ x 6′) 1 12.3 0.43 Use 1/4″ instead

I didn’t include the trifold mount.

For what it’s worth, if I weigh all the kit parts together (or if I add up all the individual weights) — including balsa scraps, decal backing, etc. — I get 4.5 oz.

Also note that the 24 mm engine mount tube and engine block weigh more than the 18 mm one, but the 5055 centering rings weigh less than the 2055 ones, with the result that the new motor mount will weigh just a little more than the old one. Of course the motor going in it will weigh more than a C6-3, so that will have to be adjusted for in the nose weight.


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