Post by Mark on Jan 7, 2009 14:28:05 GMT 1
My brother managed to surprise me for Xmas. A flying model Honest John rocket kit. I flew the 'Estes' type model rockets quite a lot up to a few years ago, having built models as big as you could without having to get an explosives licence to buy the motors. However, the laws have recently changes, and you can now buy much larger motors (net propellant weight up to 1KG) with minimal paperwork. I had been mumbling about rockets and the new laws without giving it too much thought, and more or less forgotten about it. Then out popped this mid powered kit, complete with motor casing on Xmas morn
For those that know, it flies on a F or G engine, whereas up to recently you needed an explosives licence for anything other than an Estes black powder D engine. The engines are rated by total thrust - and a letter increase represents a doubling in power. E.g. an F is twice and big as an E.
This is quite a simple kit to build, but your construction technic needs to be sound as the motor will accelerate the model to several hundred miles per hour in a couple of seconds and get it to a height of over 1000 feet.
5 minute epoxy is the glue of choice for this. I don't normally like 5 minute epoxy as it is slight flexible even after it's set, and doesn't stick to hard surfaces that well. However, as the model is madel of a heavy duty card tube and ply wood it should take the glue well. Also, as the model is subject to quite a lot of stress, landing on the end of a parachute as well as the take off, the slightly flexible nature of the 5 min epoxy will help absorb energy and will hopefully make the model more resilliant.
The nose and tail cones are balsa.
Progress so far. The motor mount has been glued in place, and holes drilled in the nose cone to take several ounces of lead shot.
The balsa is very soft, and quite rough, so the nose and tail cones are getting a good dose of sanding sealer, in an effort to make them a bit tougher, and to get them smooth.
Photos to follow - I haven't got my camera with me at the moment.
For those that know, it flies on a F or G engine, whereas up to recently you needed an explosives licence for anything other than an Estes black powder D engine. The engines are rated by total thrust - and a letter increase represents a doubling in power. E.g. an F is twice and big as an E.
This is quite a simple kit to build, but your construction technic needs to be sound as the motor will accelerate the model to several hundred miles per hour in a couple of seconds and get it to a height of over 1000 feet.
5 minute epoxy is the glue of choice for this. I don't normally like 5 minute epoxy as it is slight flexible even after it's set, and doesn't stick to hard surfaces that well. However, as the model is madel of a heavy duty card tube and ply wood it should take the glue well. Also, as the model is subject to quite a lot of stress, landing on the end of a parachute as well as the take off, the slightly flexible nature of the 5 min epoxy will help absorb energy and will hopefully make the model more resilliant.
The nose and tail cones are balsa.
Progress so far. The motor mount has been glued in place, and holes drilled in the nose cone to take several ounces of lead shot.
The balsa is very soft, and quite rough, so the nose and tail cones are getting a good dose of sanding sealer, in an effort to make them a bit tougher, and to get them smooth.
Photos to follow - I haven't got my camera with me at the moment.