The Joys of Tools

It sure is helpful to have good tools. It's even more important when you have someone who knows how to use those tools!

As yet another diversion in the Saturn V build, I'm working on an interesting two-stage rocket. More on some of the interesting bits later. For now...

The booster will be a D12, the sustainer will use an 18mm blackpowder motor. The booster's body tub is 35cm long, BT-80; the sustainer is BT-60. A transition between the two is needed, with a hole bored through to enable sustainer ignition. I have a 60-80 transition from BMS that just needs the hole.

How to bore the hole? I'd like the hole to be tapered, fairly smooth, dead center, and straight through. I don't have a drill press, a lathe, or a milling machine, and I'm certainly not trusting my hand drilling skills for this. (Yes, in fact, I only really need the two ends to be centered up, and the first, oh, couple of centimeters to be straight along the axis. Still, I'm not trusting this to my hand drilling!)

While checking with various friends, I ended up scheduling a business trip east that included a weekend swing by my parents' place for a visit. Dad has a small workbench drill press. He doesn't have quite the right size drill bits or mills, but he does have a couple of hole saws that are close. To make a long story a bit shorter, between the drill press, the hole saws, and the mill, along with Dad's skill at jury-rigging things and adapting tools and techniques to purpose, we have a hole that's nicely centered up, fairly well tapered, cleaned out of all the excess stuff in and around the edges (hole saws leave a plug in the middle of the work if you don't saw completely through—and the saw, though deep enough for our job, is only about 70% of the length of the transition), and ready for final fitting to the two motor mount tubes.

Pictures coming soon to the Nescorna Rocket Works Web site.

Good tools, good skills.

Cutting Wraps

Minor mistake: I chose the wrong sequence for cutting out the wraps. It should be obvious (shouldn't it?) that you start on the easy one, and work on progressively more difficult ones, not the other way around. Oops. I started on the hardest wrap.

Luckily, that wrap, the Interstage wrap, will likely end up as the fodder to patch the ullage rockets I'll remove from the other Interstage wrap, the one I actually did cut out last.

Would Be Done...

I'd be done cutting out the wraps except that...

I got the extra Interstage wrap, so I could patch over the removed ullage rockets. It makes sense to cut out the extra, use the better for the rocket and cut up the other. So, one more (complicated) wrap to cut, then ullage rocket patching, and then it'll be time to decide whether to try the CA technique for attaching the wraps or the tape technique.

Wraps, Wraps, and More Wraps—and a Launch

I talked with Tony Cooper at today's LUNAR launch; Tony has a built but not-yet painted Apogee Saturn V. He cautioned that many CAs dissolve the thin wraps. I told him about the online cautions about certain brands of paint being incompatible with the wraps.

Punch line: test the CA, test the paint.

As to the launch: 2400' overcast kept temps down, but skies gray. Fun launch nonetheless. I was able to get Alpha 3 to accept a motor (last month, it wouldn't go in), and the ~55th flight was a nice affair on an A8-5. Bertha flew twice, on a D12-5 and on a C6-5; the D flight landed on the runway, chipping and cracking a fin (certainly repairable). 4TNC flew twice, on a C6-5 each time: it's a fun little rocket, though I'm concerned about the tangling parachute shrouds.

Meantime, this afternoon, I've started cutting out the last of the main tube wraps.

I'd Like Paper, Please

Wow: these plastic wraps are a pain. Seemingly pretty fragile, difficult to figure out just where to cut, nerve-wracking while cutting. I remember the paper wraps from the Estes Saturn V: much easier to work with those, and I've not even begun attaching the wraps to the tubes.

Extra Wrap Arrived

Cutting is slow: perhaps this particular wrap came from a mold nearly at the end of its life, and so worn? Sometimes, it's hard to find the little scribe lines that are supposed to be convenient cutting guides. Regardless, the extra wrap's arrived, and once I get the wrap cut out I'll remove the S-II ullage rockets and cut replacement stringers from the second wrap.

Decision to Cut

S-IC retro rocket issues are now sorted out: they were installed on the inside of the S-IC engine fairings, and blew a piece of the fairing off when they fired. One decision down (doesn't have to be made!).

The S-II ullage rockets are a different story: model Apollo 15, for example, and they should come off (the S-II wrap has four of them, Apollo 15 had none). Tim had a suggestion: get a second S-II wrap, cut out the ullage rockets, and cut pieces from the second wrap to replace the stringers.

I'm ordering a second S-II wrap, and I'll cut-and-piece.