Thursday, May 8, 2008

First Launch in several years.


I will be attending a launch this weekend, for the first time since NYpower 2004. This is going to be a low power, notification launch. That means there are some limitations - the rocket has to be under about 3 lbs, the motors installed must be under 80 newtons of thrust, max motor power is a G, there is also a propellant limit and a materials limit (no large metal parts), and there is a fairly low max altitude. But because I am planning on sticking to low and mid power, this is the kind of launch I will be doing for the foreseeable future (I sold some of my 38mm cases so I am really committed to lower power).

Pictured above is part of my collection as it was at the start of this rocketry page. Some of the rockets are gone, some are in deep storage. The three rockets highlighted with numbers are those that will make the trip this weekend.

Number 1 is the all time classic, the LOC Graduator. My oldest active rocket by far, and probably the best mid power rocket ever made. Just a simple 3FNC classic. This rocket has seen some heavy use, and it is nearing twice the production weight due to layers of paint and epoxy. But it still works, flying on as little as an E30 to as much as an H238. This weekend it will go up on F motors (I will discuss the motors below).

Number 2 is the Estes Super Nova Payloader. This is a great kit, made for motors from C to E power. Best on slower motors like the D12, E15, and others. This weekend it will fly on several different motors, probably some BP Ds and F12s. This kit has a clear plastic payload section, and is pretty big for an Estes kit. The SNP in the image is actually my old model, it is now gone and replaced with a new kit. (I did a better job this time...)

Number 3 is my LOC viper 4 - a cluster rocket with 4 24mm motor tubes. This rocket has never flown, so I hope to test it starting with 4 D motors. I will eventually (maybe this weekend, maybe next time) cluster two composite motors as well using my 24mm reload hardware. Two F39s, for example, would give nice power. Actually 78 newtons of thrust would just fit under the max for this launch... pretty nice to sneak that under the wire if I can. But I need to use two spent D motor cases as plugs before I use the two motor cluster - because the two unused tubes cant be left open; that would allow ejection gasses to escape and maybe prevent recovery. Why not 4 24mm reload motors? I cant afford that much hardware! Thats almost $200!

So I will be bringing a ton of black powder (BP) motors, including about 10 D motors. Great to cluster, as well as fly my SNP kit. I also have my 24mm composite reloads and they are:

D15-4T (3)
E11-3J (2)
F12-3J (3)
F39-9T (3)

The D, E, and F motors are right now only going to work in the SNP kit - they simply dont have the power or thrust to fly any other kit, and wont cluster very well either (J type motors, smoky formulation are hard to ignite reliably). I plan on building a new 24mm kit to take advantage of the full 24mm range of motors, something light and fairly small. The F39 will power the LOC graduator, as it requires this amount of thrust due to its increasing weight in old age. But note, the 9 sec delay is clearly wrong. I will have to replace with a shorter delay if flying the graduator, probably a 4 from the D15 if that seems to work. I also want to cluster the F39s as mentioned above. The E11s and D15s are also quite old - several years old. I have some concerns that they may be more likely to fail.

I will report back after the launch, and try to take some pictures or videos if I can.

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