Possible Star Ship kit in development

Neat.

E12-4, Steve, E12-4......

This has been great fun to follow.

I have one of your V-2 kits and all of this is encouraging me to move it from the stash to the active build queue.

Glad to hear that Bernard. Hopefully the vendors on site will have those. I could only find E12-6 hear. As it is I'm cutting it close according to the sims. I just got the CG right on this bird and it took 1.5 of weight in the nose bringing the total weight with motor to 16.oz. I may be able to shed an 1 oz. off yet. it's now twice the weight of a Bigdaddy I'll be luck to see 400 ft. Next one will be lighter.

Is there a more potent 24 mm I can but it this? Say an Aerotech of some kind?

An Aerotech single-use E15 would be perfect for that rocket (probably -4). If you want it to scream off the pad then an E30 or even an F44. All those motors will cost about $10 each in a 3-pack.

Neil thanks for that. You made me happy. Was worried about the weight.

Yeah, the single use motors are a good option. (single use). There are also E&F reloads for the 24/40 case, they're a dollar or two less per load, but you've got to buy a 24/40 case. (reloads)

I may have been a bit too optimistic. Here's what thrustcurve.org says, assuming a 4-foot rod:


I highlighted (messily) the most inexpensive single-use motors. I chose the E20 instead of the E15 because... well, they're the same, but they're really the E20, and blah blah don't worry about it; today if you buy and E15 you get the motor shown up there as an E20 (same as if you buy an E20).

Anyway.

The F44 should work well. The E30 IMHO would be fine at 45 ft/s (thrustcurve is pretty conservative), and I'd fly the E20/E15 cautiously in very low wind conditions. The E12 shows as being pretty slow here, but Estes lists max take-off weight at 17 oz, so you're right on the edge by that measure at least. I'd stick with the composites for this model at the moment, until you can put it on a diet.

E30 and F44 are best choices right now. Note that the E30 will weigh a bit less than the Estes E12, so you also might be able to take out a bit of nose weight.

Would you consider a 29mm mount? That would open up a lot of options, and one could always adapt down to 24mm. Although if you think you could shave off a few ounces, that would probably help.

Thanks again Neil. The sim showed good results with the E15 nearly 500 ft. The plot was good too. Much better than the E12-6.

Marten yes I would concider that of course. However I'm locked in with 24mm size for this weekend. Not enought time to build a second rocket by then.

If you just go to rail buttons and forget launch rods, you can use a 6' rail and probably be fine with an E-30.

Frank I thought of that but ran out of time to change them over. Next one. This is the banger tester. Plus I need to source them.

SteveNeill said:

The sim showed good results with the E15 nearly 500 ft.

Click to expand...

Just remember that the apogee is less important than the speed at the end of the launch rod. High altitude is nice; high rod speed is safe.