Hi guys
This is my first post here on TRF. My name is Andrej and I'm from Slovenia (small country in central-eastern Europe). Here is a short description of my latest project that was launched a few days ago. The purpose of this project was to get some experience with making larger motors and some new building techniques (for me at least) that are required for higher performance rockets.
The entire rocket was built from aluminum and steel except for the nosecone which had to be RF transparent and was made from fiberglass. Since I know ex motor construction is not a welcomed theme here, I'm not going to go into much detail regarding motor itself, except for some very basic information. The entire rocket is actually just a rocket motor with a welded fin can attached on the aft end and a lenght of aluminum tube on the forward end which houses electronics and a parachute.
Rocket motor is 100 milimeters in diameter, has aluminum casing (EN AW 6060 alloy), steel nozzle (42CrMnO4 alloy) and aluminum head-end (EN AW 6082 alloy) with integrated pyrogen igniter. Sugar propellant is cast into five BATES grains, which are inhibited and insulated with an organic fibre/rubber composite. Motor is ignited with a head-end pyrogen igniter which is actually a small rocket motor with four sonic nozzles that shoot the hot gas down the core. When this igniter lights motor is up and running at full thrust in about 300 miliseconds.
Nosecone (3:1 ogive) was made from several layers of glass fibre/epoxy composite in a silicone rubber mould. Plug for a mould was machined from an aluminum bar stock on a CNC lathe.
Fins were cut from a 4,0mm thick plate (AlMg3 alloy), beveled and TIG welded to a short lenght of aluminum tube. Fincan screws on to the casing, entirely covering the nozzle. Aluminum coupler is used to connect the motor with the payload bay.
Avionics used was ARTS2 as a main flight computer and a Perfectflite Stratologger as a backup (set with 2 sec delay). Each altimeter had it's own power supply, switch and a 2,5 gram BP charge.
Recovery was done with a single 48 inch X-form chute deployed at apogee. Target descent rate was 60ft/s.
Nosecone housed a BigRedBee 2M GPS tracker running at 1Watt. Power was provided by lithium batteries. In addition to GPS a ComSpec AT-2B transmitter was attached to tubular nylon shockcord in case the GPS would malfunction. Nosecone was retained to the body tube with three 3,0mm diameter plastic shear pins.
Rocket was launched from a 3 meters long aluminum rail (45 x 45mm). Launch lugs were made from polyamide.
Motor was ignited with a wireless launch controler over a secure radio link.
The rocket was tracked with a Kenwood TM-D710E transceiver connected to AvMap G5 road navigator, as well as with ComSpec R-300 receiver.
The flight was nominal. Everything worked as planed. Rocket was recovered 2km away, thanks to light winds and small chute.
Some photos from the launch can be seen bellow including launch video (which is not very good, but is the only one, since two other cameras died due to very cold weather).
https://www.youtube.com/watch?v=JJlIXvbbtNA&feature=plcp
Andrej
This is my first post here on TRF. My name is Andrej and I'm from Slovenia (small country in central-eastern Europe). Here is a short description of my latest project that was launched a few days ago. The purpose of this project was to get some experience with making larger motors and some new building techniques (for me at least) that are required for higher performance rockets.
The entire rocket was built from aluminum and steel except for the nosecone which had to be RF transparent and was made from fiberglass. Since I know ex motor construction is not a welcomed theme here, I'm not going to go into much detail regarding motor itself, except for some very basic information. The entire rocket is actually just a rocket motor with a welded fin can attached on the aft end and a lenght of aluminum tube on the forward end which houses electronics and a parachute.
Rocket motor is 100 milimeters in diameter, has aluminum casing (EN AW 6060 alloy), steel nozzle (42CrMnO4 alloy) and aluminum head-end (EN AW 6082 alloy) with integrated pyrogen igniter. Sugar propellant is cast into five BATES grains, which are inhibited and insulated with an organic fibre/rubber composite. Motor is ignited with a head-end pyrogen igniter which is actually a small rocket motor with four sonic nozzles that shoot the hot gas down the core. When this igniter lights motor is up and running at full thrust in about 300 miliseconds.
Nosecone (3:1 ogive) was made from several layers of glass fibre/epoxy composite in a silicone rubber mould. Plug for a mould was machined from an aluminum bar stock on a CNC lathe.
Fins were cut from a 4,0mm thick plate (AlMg3 alloy), beveled and TIG welded to a short lenght of aluminum tube. Fincan screws on to the casing, entirely covering the nozzle. Aluminum coupler is used to connect the motor with the payload bay.
Avionics used was ARTS2 as a main flight computer and a Perfectflite Stratologger as a backup (set with 2 sec delay). Each altimeter had it's own power supply, switch and a 2,5 gram BP charge.
Recovery was done with a single 48 inch X-form chute deployed at apogee. Target descent rate was 60ft/s.
Nosecone housed a BigRedBee 2M GPS tracker running at 1Watt. Power was provided by lithium batteries. In addition to GPS a ComSpec AT-2B transmitter was attached to tubular nylon shockcord in case the GPS would malfunction. Nosecone was retained to the body tube with three 3,0mm diameter plastic shear pins.
Rocket was launched from a 3 meters long aluminum rail (45 x 45mm). Launch lugs were made from polyamide.
Motor was ignited with a wireless launch controler over a secure radio link.
The rocket was tracked with a Kenwood TM-D710E transceiver connected to AvMap G5 road navigator, as well as with ComSpec R-300 receiver.
The flight was nominal. Everything worked as planed. Rocket was recovered 2km away, thanks to light winds and small chute.
Some photos from the launch can be seen bellow including launch video (which is not very good, but is the only one, since two other cameras died due to very cold weather).
https://www.youtube.com/watch?v=JJlIXvbbtNA&feature=plcp
Andrej
