Recommended Engine for my rocket?

[blike]

Next weekend I plan on flying my Aerotech initiator. I've modified the nose cone to carry a small digital movie camera. The nosecone itself weighs 173g (camera, nosecone, battery) and the rocket body weighs 332g. This puts the total rocket weight at 505g or around 17.81 oz.

What engine do you recommend I fly on. I'm thinking about starting with an F, then flying it on a G.

What do you all think?

 

[blike]

btw, i'm looking for single use, not reloads.

 

[MarkABrown]

You could probably get away with an F25W but it'd be safer with an F50T. Any of the 29mm G's should work fine.

 

[gothique_97]

An F20 is going to be on the heavy side. Definitely start with an F50, like Mark said.

 

[Missileman]

Rule of thumb. average thrust should be 5 times the weight of your rocket, Minimum.
17 oz. rocket or to make it easy 1.1 lbs. x 5 = 5.5 lbs of thrust
5.5 lbs of thrust x 4.45 = 25.475 ns.
so an F25 would work but it is marginal.
Remember we are refering to launch weight (including motor chute ect...)
I would use at least a 30 ns average motor or higher.
We will see pics from the onboard camara right?

 

[rocwizard]

Even an F20 is fine, heck, this weekend i saw a guy fly his initiator successfully on a D12-3. can you say low and slow?:kill:

 

[blike]

Thanks so much guys! What do you think I should do as far as delay? Would 6 seconds be too long?

Next weekend I'm planning on launching the initiatorcam on an F50 and a G80, should be fun :}

I'll post pics and videos soon after.

 

[hokkyokusei]

Originally posted by blike
Thanks so much guys! What do you think I should do as far as delay? Would 6 seconds be too long?

Next weekend I'm planning on launching the initiatorcam on an F50 and a G80, should be fun :}

Using the Initiator rocksim file from EMRR, it looks like you want a F50-6, and a G80-10

 

[gothique_97]

Originally posted by blike
Thanks so much guys! What do you think I should do as far as delay? Would 6 seconds be too long?

6 second delay on an F50 is just right. As for the G80, that really depends on the wind and the trajectory. Use a 10 second delay strictly for no-wind, azimuth flights; 7 second delay for breezier days.

 

[Stones]

An F20 pushes my 22.6 oz. (dry) V2 with no problem.
Video:
V2 on an F20-4

 

[blike]

What do you all suppose will be the best view? Outward at the horizon or downward towards the motor?

Also, can anyone run a simulation for estimated altitude? See above for the specs on the rocket. I'm going to fly it on an F50 and a G40W.

 

[hokkyokusei]

How about a compomise angle, looking out & down?

F50-6 ~ 2250'
G40-7 ~ 1500'

 

[blike]

Wierd? An F50 powering it higher than a G40? Thanks!

 

[hokkyokusei]

Aaargh! Whoops, good catch, I put those the wrong way around!

F50-6 ~ 1500'
G40-7 ~ 2250'

Very sorry about that!

 

[scm86]

scroll to the bottom of the page and there is a picture that shows the field of view for the newtons third video system, ive played with it a bit, and the angle they have there gives great video. https://www.newtons3rdrocketry.com/products.htm

be sure to post anything you get from the flight!

Scott McNeely

PS: if you can find an Ellis G35-6, it should provide good video. its a long burn white lightning type motor.