I posted a comment on George's original August thread about how clever it was to use the 3 booster elements, effectively as an airborne launch tower for the sustainer. I was so impressed, that I decided to have a go at using that principle myself.
There is a bit of a difference, of course. His is an artwork masterpiece of intricate and ingenious construction in carbon magnificence ( Just watch some of the youtube construction videos, it's next level stuff. Whereas mine is a pale imitation in cardboard wood and glue powered by conventional composite motors.
Mine has a lower central core the same diameter as the sustainer surrounded by 3 slightly narrower boosters, bonded onto the lower core, to provide an interference fit for the sustainer.
The central core has no motor in it. Instead, it contains only a control sled and battery to ignite the sustainer. The wiring goes through a bulkhead into a small space that contains a connector for the upper stage fuse. Upon ignition it leaves behind the e bay still attached to the boosters and core. The upper motor mounts are partially contained in the coupler between the 2 stages. Apart from that, the sustainer is entirely conventional. The motor ejection and deployment is from below a small section below the nose, that contains an mf radio/GPS transmitter and altimeter. The chute has a JLCR. The motor is an F25 aerotech.
The boosters each have 2D9- 5 20 ns 18 mm Klima motors and 1 D9 plugged for 9 in total.Not sold in the US, I m afraid ,but a little smaller and more powerful than estes D s. Each booster has a 15 inch chute.
On the day we had perfect flying weather with 2 to 4 mph!
The launch is not quite vertical, as one of the nine motors did not ignite.
As it was a first flight, I set the timer control for the sustainer to ignite fractionally before burn out on the boosters, for zero coasting, to avoid any risk of arcing over before upper stage launch.
I got all of it back, flyable again with zero damage to fins etcetra, which just proves the soundness of George's concept.
Vid attached, hopefully.
In the background, you can hear the range safety officer saying " you lucky lucky expletive deleted", which has become a kind of in joke, every time I have a successful cluster.
View attachment VID_20241013234514.mp4
There is a bit of a difference, of course. His is an artwork masterpiece of intricate and ingenious construction in carbon magnificence ( Just watch some of the youtube construction videos, it's next level stuff. Whereas mine is a pale imitation in cardboard wood and glue powered by conventional composite motors.
Mine has a lower central core the same diameter as the sustainer surrounded by 3 slightly narrower boosters, bonded onto the lower core, to provide an interference fit for the sustainer.
The central core has no motor in it. Instead, it contains only a control sled and battery to ignite the sustainer. The wiring goes through a bulkhead into a small space that contains a connector for the upper stage fuse. Upon ignition it leaves behind the e bay still attached to the boosters and core. The upper motor mounts are partially contained in the coupler between the 2 stages. Apart from that, the sustainer is entirely conventional. The motor ejection and deployment is from below a small section below the nose, that contains an mf radio/GPS transmitter and altimeter. The chute has a JLCR. The motor is an F25 aerotech.
The boosters each have 2D9- 5 20 ns 18 mm Klima motors and 1 D9 plugged for 9 in total.Not sold in the US, I m afraid ,but a little smaller and more powerful than estes D s. Each booster has a 15 inch chute.
On the day we had perfect flying weather with 2 to 4 mph!
The launch is not quite vertical, as one of the nine motors did not ignite.
As it was a first flight, I set the timer control for the sustainer to ignite fractionally before burn out on the boosters, for zero coasting, to avoid any risk of arcing over before upper stage launch.
I got all of it back, flyable again with zero damage to fins etcetra, which just proves the soundness of George's concept.
Vid attached, hopefully.
In the background, you can hear the range safety officer saying " you lucky lucky expletive deleted", which has become a kind of in joke, every time I have a successful cluster.
View attachment VID_20241013234514.mp4
