It's official. As of May 2009, I am a Tripoli Rocketry Association member :)
Work has begun on my Level 1 certification rocket. When finished, it will be 4" diameter x 6' tall. I will be using a Hypertek hybrid motor for my attempt (due to the current restrictions on solid propellant in Victoria). RockSim seems to think that the rocket will tip over at about 3,000' on the first fire of the grain and at about 4,000' on the second. The 300cc tank is the smallest in the Hypertek range and is the only tank that allows for two flights on the one grain.
I will undertake my certification flight if I have everything ready at the start of June. As the note included with my membership documentation said "Welcome to High Power!"
Flying on an Aerotech G71R, the boost was very fast (thus resulting in me not getting more than a smoke-trail) and dead-straight with no obvious rotation, the two 18" parachutes popped out right on apogee (10 second delay selected) at about 2200 feet (as estimated using RockSim).
The spike came down without a scratch less than 100m from the launch pad. A perfect flight from what has proven itself to be a fantastic kit. Oh, and this was my first G powered flight!! Amazing stuff :)
Mr Stabby - Scratch-built rocket flying on an Aerotech RMS E18 - Perfect boost, dead staight despite the light winds and recovery was right at apogee. It returned to Earth under two 12" parachutes, landing less than 150m away. Launched at Serpentine, Victoria with Tripoli Rocketry Association Australia. RockSim predicted altitude of about 980'. The motor spat when the ejection charge fired but was recovered less than 20m from the launch site. Very happy to have that back! (Click for bigger images)
Estes Big Daddy kit flying on an Aerotech RMS E18 - Perfect boost and recovery was slightly after apogee. The motor had a 7 second delay and RocSim suggested that a 6 second was more appropriate. Recovery was with the same two 12" parachutes that brought Mr Stabby back down a couple of hours before. Touchdown was less than 100m from launch. RockSim estimated altitude was 1100 feet. Launched at Serpentine, Victoria with Tripoli Rocketry Association Australia. The Big Daddy is a great kit and flew very nicely on top of the reload. After motor burn-out, the rocket continued to coast to apogee, producing an amazing whistling sound! (Click for bigger images)
I've been wanting to try a couple of new techniques with my rockets - zipperless design and boat tails. I decided to build Mr Stabby to see how these worked out.
This was a fairly straight-forward build, starting with the design in Rocksim. The boat tail is actually a BT70-BT50 transition that I drilled out the center. Creating a boat tail this way was a suggestion from Bones at Suburban Rocketry, and it worked out perfectly!
The airframe comprises of 2 lengths of BT70 tube (18" long), a BT70 nosecone (10.5") and the boat tail. The fins are made from 3mm plywood for durability and the zipperless coupler in the middle doubles as an ejection baffle. Mr Stabby stands 48" (123cm) tall.
The nosecone is expoied into the top section of body tube, with a length of Kevlar thread attached.
The 'blood' dripping off the top of the rocket was created with a hand-cut stencil and painted Rustolium Cardinal Red. The rest of the airframe is Rustolium Titanium Silver - I am very happy with the colours as well as the quality of the Rustolium paint :) Two coats of clear were applied to help protect the paintwork and to seal down the decal.
Well, almost. In the next few days I will give it a couple of coats of clear gloss just to seal everything in, but it won't change the look. I decided to go with a very different paint job to the stock rocket, and am happy with the result - nice and bright! I shouldn't lose that now.
I originally thought about painting it yellow from top to bottom, however after a coat of primer, a coat of white and a coat of yellow, the red line for the launch lugs was still bleeding through, so a coat of orange hid that.
At the moment, solid rocket motors with more than 62.5 grams of propellant aren't allowed to be flown in this great state of Victoria. Worksafe are currently reviewing their regulations and are open to submissions on how the explosives act can be updated. The good news is that Tripoli Australia and the Australian Rocketry Association have put aside their differences and are working together to try and get the law updated as quickly as possible. But for now, the Excel may simply sit and look pretty in my lounge room...
Over the last few weeks I have been working on my Binder Design Excel 38mm. I had held off building it until my replacement fins arrived.
Cutting the fin slots was a nerve wracking experience! After getting advice from other builders and reading all I could find on the web, I put knife to tube. I masked out the area to be cut using masking tape and, armed with a brand-new #11 blade and a right-angle straight-edge, slowly cut the slots. They turned out perfect :)
The 10-ply fins are solid. Very solid! So solid that it took ages to sand them down. After sanding, they got a thin coat of finishing epoxy and then more sanding. They've turned out smooth... Ooohhh.. Smooth.
The instructions showed both forward and rear centering rings being glued onto the motor mount tube and then installed in the rocket prior to attaching the fins. I differed from this step by not gluing the rear centering ring - allowing it to be removed. Fins went in next and having access at the rear allowed for the application of internal fillets on all fins as well as attaching the rail button.
Apart from installing the Aeropac motor retainer, The rocket is built!
I'm still debating with the colour scheme - should I go stock or paint something different... I'll make a decision on that after I've given it a spray of undercoat.
At the start of the year I purchased two Binder Design kits - the Excel 38mm and the Spike. Over the last couple of months I have been working on the Spike and am very happy with the end result!
Standing 30" tall (76cm) doesn't make it the biggest in my fleet (that honor goes to the Estes Mean Machine at 6.5" tall!) but I think it's one of the best kits I have put together to date.
The kit comes with a plastic nose cone, ply centering rings, heavy-duty cardboard body tube and motor mount, very nice high-quality plywood fins, rail buttons, tubular nylon shock cord, 18" parachute and detailed step-by-step instructions.
After running the design through rocsim, I added a couple of gramms of weight to the nose (there's a note on the front page of the instructions about this) for stability. I deviated only once from the instructions with regard to building the fins. Instructions call for mounting the two centering rings and then glueing in the fins - I didn't glue in the rear centering ring, allowing me to apply internal fillets to the through-wall fins - I believe that this will make for a more robust rocket.
I also made the decision not to use the rail buttons, instead using a 1/4" rod lug.
Almost 18 months ago I found an old telescoping light stand that was being thrown out. It seemed solid and I figured that I'd put it to use one day... Well, that day has come!
I've removed the telescoping sections and have now turned up a drop-in slug with a 1/8" launch rod fitted in the middle. I am half-way though making a 2nd one that will hold my launch rail as well as one for a 1/4" rod. It was flight-tested last weekend and am very happy with the results :)
Perfect boost! Flying on an Estes C6-5, the joystick leapt off the rod and screamed straight up into the sky. The 2nd flight, however, was somewhat more dramatic!
Rocketry 
