E9-0 and the rocket sled

Iv'e had one launch using an E9-8 with my rocket sled which is the perfect thrust I've found (video to follow). I called me local hobby store to see if they could get in E9-0 motors for staging. They told me the E9 series has been discontinued. Does anyone know anything about this and if there is something I could substitute it with? I think the sled could reach 500ft or close to with E9s.

You need an E12 0 and those are available. A D12 0 would also work.

Probably poor communication. The current Estes E impulse BP motors are listed here. https://www.estesrockets.com/rockets/engines/e-engines

You asked for the Estes E9-0 motors which were certified but never put into production because the thrust is too wimpy to use as a booster for a 2-stage rocket so the information you received is technically correct. The other Estes E9-4, -6, and -8 motors were put into production and are still in production. These motors have a longer burn but lower thrust than the Estes D12 motors so they work best in lighter rockets.

Later Estes put a higher thrust E12 series of motors into production in addition to the older E9 series. The Estes E12-0 motors are certified and in production. They have much more thrust than the E9-0 and are suitable as boosters for a 2-stage rocket. The Estes E12-4, -6 and-8 have the same thrust as the D12 motors but have a longer burn. They are in production and are suitable for heavier rockets than the E9 motor line.

Bob

Thanks for the info. Unfortunately for me E12s will have to much thrust for my rocket sled. I've launched it with 2 D12s staged which once it got up to speed caused it to go air airborne. I guess I could stage multiple E6s into an E9-8 or I'll have to figure out a way to use a spoiler to keep it on the ground.

Through out out your ideas for me to ponder. Thanks

mbecks,

At the bottom of this thread, there should be a list of related threads which are actually really interesting.

Shouldn't you be able to keep the speed down by trimming with mass?

More m for the 12/9 increase in thrust. But in this case, drag (sliding friction) is also proportional to m.