Safe Liftoff Weight

[Hospital_Rocket]

So here is my quandry

I have a project called the Video Viper, its a Viper-4 with an add-on payload containing a Boostervision High Power Camera. It weighs in fully loaded at just over three pounds.

I should not be able to pick this up with 4 BP motors, however somehow RockSim thinks I can.

Would someone please look this simulation over and tell me where I have gone awry?

Thanks

Al

 

[cjl]

Rocksim appears to be just fine - that weight is no more per motor than a stock estes Phoenix, so as long as it is DEAD calm, you'll be fine. However, I would still vote for F24's, because those motors would have so much more flame and noise. Honestly, though, you'd be fine with 4 D12-3's or E9-4's (D12's would only get it 300' or so though).

I still vote for F24-7W's

 

[Stymye]

look at the launch data,it takes 124" of rod to become stable

 

[Hospital_Rocket]

Styme -

Thanks

That was the piece of the puzzle I could not grasp. Looks like E-30's for this beast.

Al

 

[cjl]

Yes, but in reality it should be fine. I've flown rockets that Rocksim said would take >15' to be stable off a 3' rod, and they were fine (in DEAD calm). However, the E30's would be a safer bet (as long as they all ignite).

 

[BobCox]

Originally posted by cjl
Yes, but in reality it should be fine. I've flown rockets that Rocksim said would take >15' to be stable off a 3' rod, and they were fine (in DEAD calm). However, the E30's would be a safer bet (as long as they all ignite).

Agreed. You can fly just about anything in DEAD calm. When RockSim says you need a really long launch rod, believe it. You will get some serious weather-cocking if you have any signficant wind.

 

[cjl]

Absolutely - that's precisely what I meant. If it gets off the pad and is stable, it will go straight no matter what speed it flys at (well, almost). In any wind, it will weathercock though.