I have just about completed the build of this one. It is a 4.3x upscale of the Estes Super Flea Mini-Brute. It uses Semroc LT-225 for the airframe and stands just about 32.75" tall, and it incorporates a few neat features. These include:
- interchangeable motor mounts
- a removable, replaceable baffle
- zipperless design
- a small payload section, suitable for a video camera or an altimeter.
Semroc doesn't offer couplers specifically for LT-225, but they don't have to - their own BTH-70 tubing works perfectly as coupler stock for it. I took advantage of that fact for the interchangeable mounts; they all fit into sections of BTH-70 that are slid into the tail of the Superior Flea. The mounts are kept from moving forward by the coupler tubing at the top of the lower section of the rocket, along with spacer couplers as needed. The baffle also fits into that section just below the bulkhead, it it is held in place by the motor mount. The mount is kept from being ejected by removable rivets inserted through the airframe near the aft end.
The first RockSim 8 file features a 7x18mm cluster. Somebody forgot to tell me that 7 BT-20 motor tubes can't fit into a BT-70; oh, well, I did it anyway.
I had to fool around with tube wall thicknesses to get RockSim to allow me to put the 7 tubes in there, so the component details will look a little off for the motor tubes in that file. The Superior Flea gets about 1170 feet on seven Estes C6-7's and about 1180 feet on seven mythical Quest C6-7's. (Too bad that Quest doessn't offer them with that delay!) It gets 500 feet on a mix of six B6-4's in the ring tubes and a C6-0 in the core, with an almost perfect DV.
I have RockSim 8 files of it that also feature a 29mm mount and a 38mm mount that I will post tomorrow... or, I should say, later today. I will also pist some pics of the almost completed build. But it's late now, and I need to get some sleep.
Length: 32.7375"
Diameter: 2.34"
Fin Span: 10.34"
Weight: 14.73 oz. (18mm cluster version)
C6-7 (7)...............1171'......Dv 7.6 FPS
B6-4 (6)+ C6-0..........503'......Dv 2 FPS
C6-5 (3)+ B6-0 (4)......714'......Dv 11 FPS
C6-7 (6)+ B6-0.........1058'......Dv 15 FPS
MarkII