New Design -- Simple Twin

[CPMcGraw]

A nice, easy design for two-stage action. All simulations are safe using a 36" x 1/8" standard launch rod.

Length: 19.50"
Diameter: 1.04" (ST-10/ST-8)
Fin Span: 4.54"
Weight: 1.27 oz

An image of the simulation runs (24) attached below.

Enjoy!

[nvrocketeer]

Bravo! Next question: Assuming the uppermost tube is a payload compartment, what sort of maximum payload weights would we be looking at?

[JRThro]

Nice one, Craig.

Those are great, consistent deployment velocities. I like the larger forward section transitioning to the aft section.

Are you using friction fit motor retention?

Oh, and do you have any single-stage simulation results?

[CPMcGraw]

Bravo! Next question: Assuming the uppermost tube is a payload compartment, what sort of maximum payload weights would we be looking at?

The attached image shows six runs, using two engine combinations: C6-0/B6-6 and C6-0/C6-7. I selected three payload mass values for comparison: 1/2 oz, 3/4 oz, and 1 oz.

A 48" x 3/16" rod is advised for any payload flights, as nearly all of these runs took 32" of guidance or more.

An interesting observation is that even with the longest delays, the model is still heading upward when the deployment occurs. Perhaps I can tweak the design with the fin sizes to reduce the high Dv numbers... :rolleyes:

[CPMcGraw]

Nice one, Craig.

Those are great, consistent deployment velocities. I like the larger forward section transitioning to the aft section.

Are you using friction fit motor retention?

Oh, and do you have any single-stage simulation results?


I am using friction-fit for this one. Using an engine hook with ST-8 is difficult at best. This model uses butt-joint coupling between the engines, like older Estes designs.

Attached at the bottom are the single-engine results.