Building the Estes Xarconian Cruiser (part 10)

If you’ve been reading these posts with bated breath, waiting in dreadful anticipation of the moment when I screw up royally, you can relax now.

I applied fillets where I didn’t earlier: along the outboard pod joints, under the transverse top fin thing, along the intake tubes. Then I epoxied in the motor mount.

Oops.

The Estes instructions, in their terse, near-wordless way, didn’t make clear how far into the body tube the motor mount should go, so I put it where I usually do: tube flush with tube. Wrong. There’s a tail cone, remember? I did… after the epoxy cured. It should have gone in about a half inch less — just far enough in to accommodate the tail cone shoulder, putting the motor mount tube about flush with the tail cone.

Look, I’ve never built a rocket with a tail cone like this before, okay?

So what to do? I considered trying to cut/scrape/pound/Dremel/vaporize the motor mount out of the body tube and replacing it with a new one, but I had little confidence I could do so without seriously damaging the rocket. I did give it a couple good whacks just in case I’d used inadequate amounts of epoxy for a secure hold, but no go.

(And of course, had I done what I usually do and glued the motor mount in at the beginning, I could’ve just tossed it and the body tube in the trash and started over. But no, I had to convince myself dry-fitting it for fin mounting and gluing it later was the best of both worlds. Well, it is, if you don’t screw up the position when you glue it.)

Probably the smartest option would have been to just leave the tail cone off, but I couldn’t bring myself to do that.

In the end I decided to just go with it. I can get the motor in with no trouble, Getting it out will almost undoubtedly require poking it from the front with a dowel, but that’s no biggie — good thing there’s no baffle. And I don’t think the tail cone’s in danger of melting even with the motor nozzle slightly inside it.

(Hmm. I just this moment had another idea. I don’t know if it’ll work, but I can try it. Can I straighten out the motor hook and then bend over just the tip of it, to effectively make it a half inch longer? If so then I can glue in a second thrust ring, and problem solved. I’ll try it with a spare hook first.)

Anyway, there’s my grand goof. Like I said, you can relax now. I’m done with the mistakes.

Because I redshifted this thing to a 24mm mount, I needed to modify the tail cone. I used a razor saw, some small files, and a Dremel to cut a notch right down to the tail cone shoulder for motor hook movement.IMG_3303

I used tube plastic cement to glue the tail cone on. Wait, wasn’t I going to spray it black first? OK, now I’m done with the mistakes. Anyway, if masking for tail cone painting is the hardest part of the paint job, I’ll be shocked.

I still need to get rid of the seams on the nose cone and scuff it for painting, add nose weight, oh, and fill and sand the tube spirals on the outboard pods. You may be asking, Rich, wouldn’t that last item have been easier before you glued the pods on? And my response is, Shut up. OK, now I’m done with the mistakes.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s