So this past Wednesday I got a package from the wonderful people at Balsa Machining Service (BSM) which contained everything I needed to build Two rockets that I have been looking forward to building for some time now. The first is the Classic Orbital Transport.
I have wanted one for along time. Orbital Transport is probably the rocket that got me interested in rockets in the first place. I used to spend hours down in the crawl space playing with my dads model and just imagining it fly. Then I found the instructions and decals for it on line so I bought the stuff my dad needed to fix his, (I was not the one that broke it in case you were wondering) printed a new sheet of decals and finally got to see it fly. Then I found out that BSM sold the fins for it laser cut and everything so I decided I would build my own. I bought the fins well over a year ago when I got the parts to build The Dart and have been waiting for the next time I ordered to get the nose cones and other things which I needed. It just didn't make much sense to pay $6.00 shipping for $2.00 Nose cones. Anyway the result is below, ready for sanding sealer and paint. The above picture is of my jig to keep the fins straight while the glue dried. I knew those old text books would come in handy.
My second project is the rear ejection design mentioned in my last post. It was a good build that I wish I had taken more pictures of because certain aspects of it would be difficult to just explain.
The first step wast to cut the tubes to length and mark them and then cut out the slits for the ejection gases. Once that was done I realized that there would be a lot more to building this rocket than I had originally anticipated. The most significant challenges was how to mount the shock cord and then there was no room for recovery wadding. So I could make the rocket go up but the landing part wouldn't be pretty.
So here is my solution put a screw eye in the forward bulkhead attach the shock cord to that and then stick a BT-5 body tube around it until it is into the recovery payload tube. The above picture shows how I used a spent 13mm motor to attach the body tube. By the way if you like to design and build your own rockets I recommend keeping your spent motor casings and investing in a miter box and razor saw. They make great centering rings and tube couplers and thrust blocks and are a lot cheaper, but I digress. I then had to figure out a way to get the thing into position without gluing the shock cord to the side of the body tube. This involved another BT-5. The recovery wadding problem I solved by using a baffle made out of stainless steel kitchen scrubby pad stuff. Again I wish I had taken a picture.
Keeping the fins on the rocket and straight has always been a challenge. Again the text books came in handy. As a random side not I used my Statics &Dynamics, Space systems elements, Propulsion, Mechanics of Flight and Numerical methods books. To mark the tube I drew the angles on a pizza box and cut out a hole for the body tube.
And here is the final product. Ready for sanding sealer and paint. All in all it was a good build and I am excited to finish and fly it.
Length: 21"
And I beheld that I had the components for such a rocket. Therefore, I did open the program Rocksim and did create a new file. And I beheld the file that it did bring exceedingly great joy to me. Therfore I began to lay out the rocket and to cut the centering rings and to trace the fin templates onto balsa. And the workmanship was exceedingly fine for it was mine, or in other words it was good enough for who it was for. Wherefore it did enter into my heart to finish building this rocket that it may one day ascend to heaven and there deploy its parachute and descend slowly again unto the earth from whence it was taken and to then rise again and again and bring joy to all who behold it. And again I say unto you that if your faithful unto the hobby of model rocketry that this rocket will bring you joy and rejoicing all the days of your life. And thus it is. Amen.
