I posted about this in the Half Baked thread as well as the cluster thread but started to make progress tonight so decided it deserved its own thread.
I am going to try to make the Leonora Christine from the book Tau Zero (well an artists rendition of the spaceship from that book). https://en.wikipedia.org/wiki/Tau_Zero
https://manchu-sf.blogspot.com/2012/04/empire-du-sommeil-tau-zero.html
There was actually a 3D design out there but I decided to redesign from scratch and use that design as well as the pictures as inspiration. As mentioned elsewhere, I set this up to allow for an 8x mini-engine cluster + 24mm/18mm engine in the rear. Planning to use A10-0T engines for the cluster and made rear engine mount to handle 24mm or 18mm engines. That is a BT60 tube in the rear and a BT50 tube inside the big cone giving it structure (w/ 3D printed centering rings). I am pretty happy with the 3D design I came up with for the cluster setup but not as pleased with the rear engine design - may redo that.
I also realized this was something I could actually simulate (more or less) in Open Rocket - been doing lots of ring tails lately so have not even bothered. None of the weights are accurate but it is great to get a sanity check on where CP is with that massive nose cone and other oddball elements. I was really surprised that OR puts the CP so far back in this design. Also nice to see what that mini engine cluster does to this. Those mini engines have a ton of power for a short duration so with 6 of them (it seems like OR maxes out at 6 engines in a cluster) it was going insanely fast off the rail. I dropped down to 4 engines (my thinking is that I can put 4 engines in bays and leave 4 empty bays to eject gas on engine burnout (so my cardstock nose cone does not explode). Still pretty fast off the rod -- 24.5m/s and going to a respectable 114m. Finally, found out is that a C6-3 seems like it will work well in the rear (double the thrust duration + 3 sec delay deploys chute around apogee).
I will mess with OR more once I build this thing and see how much it really weighs.
I am going to try to make the Leonora Christine from the book Tau Zero (well an artists rendition of the spaceship from that book). https://en.wikipedia.org/wiki/Tau_Zero
https://manchu-sf.blogspot.com/2012/04/empire-du-sommeil-tau-zero.html
There was actually a 3D design out there but I decided to redesign from scratch and use that design as well as the pictures as inspiration. As mentioned elsewhere, I set this up to allow for an 8x mini-engine cluster + 24mm/18mm engine in the rear. Planning to use A10-0T engines for the cluster and made rear engine mount to handle 24mm or 18mm engines. That is a BT60 tube in the rear and a BT50 tube inside the big cone giving it structure (w/ 3D printed centering rings). I am pretty happy with the 3D design I came up with for the cluster setup but not as pleased with the rear engine design - may redo that.
I also realized this was something I could actually simulate (more or less) in Open Rocket - been doing lots of ring tails lately so have not even bothered. None of the weights are accurate but it is great to get a sanity check on where CP is with that massive nose cone and other oddball elements. I was really surprised that OR puts the CP so far back in this design. Also nice to see what that mini engine cluster does to this. Those mini engines have a ton of power for a short duration so with 6 of them (it seems like OR maxes out at 6 engines in a cluster) it was going insanely fast off the rail. I dropped down to 4 engines (my thinking is that I can put 4 engines in bays and leave 4 empty bays to eject gas on engine burnout (so my cardstock nose cone does not explode). Still pretty fast off the rod -- 24.5m/s and going to a respectable 114m. Finally, found out is that a C6-3 seems like it will work well in the rear (double the thrust duration + 3 sec delay deploys chute around apogee).
I will mess with OR more once I build this thing and see how much it really weighs.