In case anyone is still following, here's another weekly update:
Weekly Summary:
It’s been a very busy week, yet the visual indications of progress on rocket construction is minimal! In short, the bulk of efforts were devoted to fine tuning the simulations, Class 3 Submissions, and motor work.
Rockets in a hypothetical world:
As indicated above, much time was spent in the simulation world. Many hours were spent working with Rogers Aeroscience, RASP, Burnsim, “Research Notebook”, Black Rock “Airframe data page”, CAD, Adobe pdf, and Class 3 Word Submissions as they were populated and revised. Trying to integrate some accuracy into the simulation of the 2 stage project through the current version of RASAero has been an adventure; a great many thanks to Jim Jarvis for sharing his time, experience, and knowledge with me throughout the process! Nevertheless, the paperwork has been submitted and an initial conversation with Kent Newman, who is the head of the C3RC was promising. Without going into too much detail, the sustainer of the
September Fate-Carbon Slipper project sims to a significant altitude. I won’t disclose the projected altitude because A) I don’t believe it myself B) those that know me understand that I value simulations to a some degree; but I’m a much bigger fan of practical experience, and C) flying to such altitudes is a tall task; I would be downright ignorant to believe success is a given and downright flattered if the project successfully made it to even half of the simulated altitude!
The consequence of producing an ambitious simulation is that a few steps will need to be taken to keep the rocket on track (within a few degrees of vertical). In short, the launch tower will be extended from 12’ to 16’, the fins airfoiled such that a spin is induced, and lastly, the delay between booster motor burnout and sustainer ignition reduced by a few seconds.
When I escaped the confines of a computer, I was able to do some work to September Fate and a decent amount of work to the motors for Balls and Hamster Dance.
Booster lamination
I’ll admit that
September Fate has sat idle for some time… about 3 years since I last worked on it. When we planned on going to Balls 19, I layed up the airframe, tacked and filleted the fins, and completed tip to tip lamination on two of the three sides. It looked something like this:
And this:
The dull look is from the peel-ply. The smoothness and associated sheen shall return as the rocket gets closer to completion (though don't expect a Jarvis-like piece of artwork here!)
Let’s cover up the G-10 cores, shall we? Using few words and a couple of pictures, here we go:
No touching the carbon fiber with grubby, oil laden hands now! Cotton gloves keep the oils off the fibers; we'd much rather have the fibers absorb resin than oil. Fiber orientation is important; figure out what you're trying to accomplish, then orientate the fiber direction(s) to achieve your desired result.
All layers are laminated, then carefully covered with peel ply. Epoxy is added to the top of the peel ply until most of the air bubbles are gone; we should see a uniform colored layer without little to no white spots (voids).
Not saying it wouldn't be beneficial, but vacuum was not used here as the booster will not be traveling fast enough to warrant the extra effort.
Work remaining to be done to the booster fin can: trim the edges, sand airfoil into fins, cover the leading edges, bevel the leading and trailing edges, make it pretty.
Sconnie Motor Works
On the motor side of things, it was a good week for progress. We mixed the *final* batch of propellant for Balls and I completed much of the cutting, coring, facing of the grains. Liners were cut, single use motors assembled, and a pair of static test motors prepped.
Here's the pile o' propellant as I begin assembling motors. From Left to Right: 114-8 grain O4400, 98-7G N2488, 75moon M825, 75-5G M1060, 54-7G L900, 54-7G L900, 38-6G J220, 29-7G static and flight, 29-5G, 29-3G flight and static, 19-4G F38. All motors are my "Superballs" flavor.
Static testing two 29mm motors at lunch today and making smoke grains tonight. To be continued….
-Eric-
?
