Building the Semroc Sprite (part 6)

Sorry about the radio silence. I’ve been procrastinating a lot on the Mega Sprite and anything else rocketry related, and busy sick out of town and so on. This week I went into last second rush mode, which always works out well, to get ready for tomorrow’s launch. (Oh yes, I do go to launches.…

Building the [scratch] Mega Sprite (part 9)

Sorry about how long it’s been since I updated you on this project. Here’s where it’s progressed to: So yeah. Into the trash with it. I did such a sloppy job making and mounting the fins that I decided to go right back to square two. Square one being the ring fin, which is round,…

E9 demise

There’s been news recently about Estes, like that a new owner will be buying it from bankrupt Hobbico, but also that they’re discontinuing the C11 and E9 motors. Well hm. I’ve seen some comments like this: “the E9 was noted for its unpredictability – you never knew whether the rocket was going to have a…

Building the [scratch] Mega Sprite (part 8)

I trimmed the tabs on the fins, and then trimmed the fins themselves. The former I did with a hobby knife. The latter, due to the CA I’d put on the tip edges, I shaved off with a band saw. Might still need a bit of sanding but it’s close. And I think the new…

Building the [scratch] Mega Sprite (part 7)

Perhaps you noticed my blunder before I did. By treating the tip edges of the fins with CA, I ended up with non porous surfaces where the tip pieces are supposed to be glued on. Oops. I also discovered a bubble on one of the fin papers which I’ll have to address somehow. Later. For…

Building the [scratch] Mega Sprite (part 6)

The fin centers aren’t papered (I guess that’s kinda obvious) so were done a bit more conventionally. The one unusual thing was that I cut the interior weight reducing holes by hand, that is, without a straightedge. There’s nothing critical about their size or appearance, so why bother — less clumsy than trying to hold…

Building the [scratch] Mega Sprite (part 5)

I’m reasonably happy with the ring fin. There were some little gaps along the edges between layers but some yellow glue seems to have filled those pretty well. Now the flat fins. Normally when I paper fins, I cut out the fin, round the leading edge, then wrap a single piece of paper over the…

Building the [scratch] Mega Sprite (part 4)

I bought a piece of balsa. It came from Michael’s and I’m not terribly impressed with it; it’s rather warped. Still, it’s only going to be a thin skin on a thicker, flatter piece, so I think it’ll be all right by the time I’m done. I’m doing the fins like the Mega Mosquito. A…

Fives

The NAR is talking about having local clubs across the country do well-publicized launches, particularly of Saturn V models, on July 20, 2019 — the 50th anniversary of the Apollo 11 landing. We discussed it at our club and we’ll probably do it, especially since the third Saturday is a usual launch day for us.…

Building the [scratch] Mega Sprite (part 3)

Here’s the body tube with cardboard mock fins taped on, and the ring fin around that. Fin size looks pretty near perfect. Could stand to cut them a bit more generous I guess. I trimmed the plywood to size, having initially cut it about a half inch wide before gluing it on. One end isn’t quite…