2+inch+(2+stage)

2inch EXPERIMENTAL 6xD12 BUILT BY DAVE THOMSON

EXPERIMENTAL 2inch DIAMETER ROCKET
 * ROCKET CONSTRUCTION**
 * This rocket is designed to fly two stage on 3xD12-0 Estes motors for the first stage and 3xD12-5 for the second stage. This rocket directly replaced the Mark I delta clipper. It also got rid of the problems associated with the first stage being too far away from the second. The first stage was butted right up to the second stage and was not designed to be recoverable.

BODY TUBE This is made from 2inch diameter lightweight drainpipe. It is easy and cheap to buy (B&Q) and does not weigh much more than the cardboard postal tubes. The main advantages over cardboard are a) Easier and quicker to prepare and get a much better finish b) Stronger for more powerful motors c) More durable than cardboard (especially if it gets wet in grass etc.) d) More easily repaired if damaged (shock tends to stay around the damaged area and not be transmitted through the whole body. i.e. Spiral tubes collapse) || I have now been using this material for a number of years and made numerous rockets out of it. You can use epoxy, cyno and PVA glues to build them. Neater edges can be made so long as you use sharp instruments. The most difficult part with this material is cutting the slots for the through the wall fins. A combination of Solar-Trim and painting was done to decorate the model. The rocket was base coated in white. The black portions are Solar-Trim. This material is easy and quick to work with (No mess and masking). It also gives a great finish. Weight is around 24oz without motor. NOSECONE The nose cone is home-made and turned on a Black and Decker drill from solid balsa. This is glued to a section of tubing making the nose cone and payload section around 14inches long. The nosecone is smoothed on the drill with fine sandpaper and then sealed with PVA glue before final coating/filling etc. Done carefully no balsa grain is visible.

FINS Fins are made from 1.5mm formica. This material is a little brittle but this nad very strong giving very little drag. Fins are through the wall onto the motor mount tube.

MOTOR MOUNT The motor mount tubes are made from standard Estes BT50 tubing. Three tubes can be mounted into the base of these tubes for a 3xD12 cluster. Scrap balsa is then used to fill in the gaps that are left. Care has to be taken to ensure the motor tubes do not twist when mounting into the airframe. The second stage was made separately in a similar way. The transition coupling was made from a short piece of 2inch tube with a 1 inch overlap onto the body tube (slots cut part way to locate over lower secion of the fins) and is a snug fit to the second to ensure no 'slop' but loose enough to be blown off during second stage ignition.

RECOVERY SYSTEM I use a 24inch diameter home-made parachute made of red ripstop nylon.

FLIGHT



First flight was at a SERFS Yatesbury meeting in 1996. The rocket boosted on the 3 D motors and the second stage kicked in at the end of the first stage burn out (no delay). The nose cone ripped off during deployment and the rocket came in hard! But the rocket only suffered slight damage to its upper section. This was cut off on the field and the rocket flew again an hour later! Image above shows the lower first stage extending beyond the lower fins