Well, the rocket hit the road for Black Rock at 6am this morning. My hands look like they were run through a blender and contracted arthritis all in the same weekend, and it's 9:54am and I'm on my third cup of coffee. I've come this far with this thread, so I'm going to see it through. Here goes.
Friday
I went home from work, still delirious from Thursday's all-nighter vac bagging the fincan. Jim had told me that if I needed to, I could meet him Saturday evening or even at the crack of dawn Sunday morning with the stuff; I was going to try and get it done on Friday night just to get it out of my hair and have some semblance of a normal weekend. Laughable, indeed.
I got home and completely hit a wall. The only thing I absolutely had to do on Friday night was apply the ablative to give it time to cure, so I pulled the can from the bag and removed the peel ply. Good compression, good saturation, no wrinkles, mission accomplished. There was some cotton batting that overlapped the peel ply a bit and got stuck, but the few cotton fibers I wasn't able to pull off will be covered by ablative anyway, so no need to bother with sanding.
Mix up a massive batch of ablative (consistency of spackling putty) and spread it on as evenly as possible, because this stuff is NOT easy to sand:
Put my phone on airplane mode and passed out at 9pm - I remember a time just a few short years ago when I wouldn't have been able to live with myself for wasting a Friday night, but this may have been the most beautiful thing I've ever seen. Woke up 8am Saturday feeling like a new person.
Saturday
Ah, the dreaded "putting it all together" time. Sure, it always takes longer than you think, but each year I temper expectations based on the previous year's gross underestimation, and still, somehow, I'm always off. I think this stems from the fact that rockets are generally built in sections; fincan, motor, etc. "Finishing" each section really means it's about 95% done; final drilling/sanding/gluing/fitting is always left to be done at the end. When you multiply this 5% of outstanding work to be performed over 10 parts of the rocket, that's a bitch of a step and it's all happening at once. "Foreseen unforeseen problems" seems to be the best way to describe it. The solution to almost all of these is an even mixture of 45% elbow grease, 45% hours on hours, and 10% ingenuity. Even if we assume that I'm an endless source of elbow grease - which, not having slept in three weeks, is an extremely dubious notion, but I've got no choice but to be - the hours are going to start to run out on us here. All we can do is get going.
I received the worst good news (or the best bad news) on Saturday morning; Jim was unhappy with the upper level wind forecasts for his flight, and was debating not making the trip. Whatever he decided, it gave me valuable extra time as he delayed his departure by a day to wait for more proximate forecasts. If this hadn't happened, I'd have been **** out of luck. So I put it out of my mind and started tackling the problems, one by one, going as fast as I can and no faster:
Problem 1
I need a forward insulating disk for the head end of my motor and an av bay bulkplate. In both instances, an accurate fit is very important. I don't have any kind of drill press or anything with which to fabricate one of these. I bought a circle cutter jig for my Dremel, only to realize that the cutting bit wouldn't touch the G10. I had to muscle it through, and the result was a very sloppy cut. So I rough cut two blanks with a jig saw and got them as close to circular as possible. My plan had been to get them "close enough" on my disk sander and then concentricize them by chucking them on a hand drill and holding sandpaper around them, but my friend Ryan had a pretty neat idea that I was able to execute on. Set up a rotary station on the disk sander table. Three hours and a bleeding finger later, we're in business:
But it made a mess, of course. So, we pause for an hour to clean up this bad boy:
Problem 1 solved. Problem 2 is the looming sanding of the ablative, but it's now about noon on Saturday and it's not yet hard enough to sand. So I put it in the shotgun seat of my car and left it in a parking lot to bake. Sometimes (sometimes) it's nice living in Texas.
While I waited for this to cure, I decided to work on my av bay. This is the one part of this project that really worked out unexpectedly; I had been worried about the challenges of an off-spec nosecone with a strong enough coupling mechanism and still somehow fitting all the electronics in the RF transparent part of it. Part 1 to the solution of this problem was done a few weeks ago with the coupler, now it's time to build a slick removable bit to keep the electronics in the tip of the nosecone and save us the mass of an allthread, because we already gave up some mass savings to the thick FWFG material (free) and the thick Aluminum coupler (no choice).
Bada bing:
The sled will weigh 1lb or so with everything on it and the flight maxes out at right around 50g. Six x #8 x 1/4" stainless screw tips will absolutely hold a max dynamic load of 50lbs, and we've saved the weight of the allthread.