2 x UPSCALE DELTA CLIPPER (Mark1) BUILT BY DAVE THOMSON ROCKET CONSTRUCTION UPSCALE ESTES DELTA CLIPPER (Mark I) This rocket was designed around the Estes Delta clipper but upscaled to around 2x the original design. The idea was to also make it 2 stage as the original. Staging would be done by burn out of the first stage igniting the second stage. The major problem would be the fact that the distance between the first and second stage to match the original design would mean that the engines would not but up to each other. I decided to not use D12-0 boosters to ignite the second stage but D12-3 instead. This would give a 3 second coast before second stage ignition and hopefully a least one of the second stage D12-5 motors would ignite! AIRFRAME The body is made from 2inch diameter postal tubing slotted together for the correct length. Cyno and PVA glues where used. The Fins are balsa and are through the wall mounting onto the motor mount tubes. 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 used silicone sealant tube cut to the correct length with around 2 inches overlap onto the body tubes. The transition tube is permanently fixed to the first stage and a snug fit to the second to ensure no 'slop' but loose enough to be blown off during second stage ignition. Weight without motors was 20oz. Overall length is 68inches. NOSECONE The nose cone is home-made and turned on a Dlack and Decker drill from solid balsa. This is glued to a section of tubing making the nose cone and payload section around 12inches 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. RECOVERY SYSTEM The rocket has two recovery systems. The first stage has its own parachute that is contained in a small housing that is moulded into the side of the second stage. When the first stage ejection charge fires and the stage falls off, the parachute is automatically pulled out from this housing from the upper stage. The system works well and doesn't get burnt from the second stage ignition. The second stage uses two three feet diameter plastic parachutes. FLIGHTS First flight First flight was at Broken Bank flying site on the Wirral (Heswall Model Flying Club). The weather was calm and very clear. The booster was loaded with 3xD12-3 Estes motors and the second stage with 3xD12-5 motors. The rocket was loaded onto the launch rail and ignitors wired up in parallel. A 12v car battery was used to ensure a good ignition. The countdown was given and the motors kicked in. The 3xD12's lifted the rocket straight and at a fair rate. There was what seemed a long time before the first stage ignited the second. When it did a plume of smoke emerged in the sky on its own and a distant sound of the motors could be heard. Second stage seemed to be around 1000 feet. The second stage carried on way up to around 2000 feet and the two three feet parachutes where only small dots in the sky. It took a long while to reach the ground and only landed some 30 feet from the launch pad!! All 6 motors had ignited and the recovery was complete. A brilliant flight, and one to remember. Above images show the first launch. In the third image you can see the to theright centre of the image the plume of smoke given out by the first stage ejection charge. Adjacent to it slightly down and right is the first stage coming down by parachute. To the left you can see the smoke trail of the second stage with a small black dot to the left of that. This is actually two small parachutes of the upper stage coming down. Above image shows my son David inspecting the rocket for damage. All was ok and no damage sustained. Last flight The rocket had flow a few more times until the fateful day. It was a clear but slightly windy day. Some others where flying at the field so it was decided to move the launch site away and behind the cars and site hut. The rocket was aimed slightly into wind and towards the Dee estuary. Motors where loaded as before and the countdown began. The first stage went well until it weather cocked quite a lot into wind. The delay of the D12-3's was too much and the rocket was heading for the ground when the second stage ignited!! The acceleration was very apparent when the second stage ignited as it accelerated into he ground with a 'thump'. The ejection charge could then be hear going off. But was buried deep into the ground so did not push off the main body. The rocket was damaged too much and never flew again. Cardboard tubing design for this size was then replaced by lightweight plastic tubing for other designs. RETURN TO THE MEMBERS ROCKET PAGE RETURN TO THE MAIN HOME PAGE