Klatuso
Well-Known Member
- Joined
- Jan 18, 2018
- Messages
- 154
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- 18
I cannot run any rocket simulation software because I have a Chromebook. It doesn't run software. So I'm building a 3FNC from Pemberton Technologies. I have two 29mm motors, an Aerotech Econojet F20-7 and G79-14. My BAR novice intuition says that these both should fly the rocket well. The F20 is weak but should get it up and parachute deployed adequately. The G79 will send it high, over 2,000 feet and the 14 second delay will not deploy the parachute at apogee but on the way down. With a padded shock cord a zipper should be prevented and letting it drop a bit could prevent it from drifting too far.
I emailed Pemberton and Apogee rockets about these motors but received rather different responses. Perhaps motor selection is more of an art than a science.
Apogee recommended against both motors. Tim Van Milligan responded personally and how impressed I was by that! I felt honored! He wrote that the F20 hasn't enough thrust and too long a delay. That concerns me. He wrote the G79 motor "would be good off the pad. But the delay is too long." But when I visit their recommended motor page for this rocket it has an Aerotech G54-14 motor. Same 14 second delay.
The Pemberton response from someone named Layne (?) was more enthusiastic. The G79 would "rock the 3FNC's world." asked for videos of the flight. "Now, the F20 may just be sufficient." and did say that he/she would need to run the simulation but was on the road and would need to run the simulation software.
Bottom line, I am pleased by the personal response to a question from a BAR who can't run the simulation software. One is conservative and the other liberal. Given that neither are completely wrong I'm still a bit confused. Obviously, what I should do is purchase an Aerotech F37W-M as recommended on the Apogee website, I don't feel like spending the $18.00. I am inclined to go with the G79, I have 80 acres and more open land around me.
I'm not starting a debate between Pemberton and Apogee, just making an observation about the art of motor selection and wondering if there are other opinions.
I emailed Pemberton and Apogee rockets about these motors but received rather different responses. Perhaps motor selection is more of an art than a science.
Apogee recommended against both motors. Tim Van Milligan responded personally and how impressed I was by that! I felt honored! He wrote that the F20 hasn't enough thrust and too long a delay. That concerns me. He wrote the G79 motor "would be good off the pad. But the delay is too long." But when I visit their recommended motor page for this rocket it has an Aerotech G54-14 motor. Same 14 second delay.
The Pemberton response from someone named Layne (?) was more enthusiastic. The G79 would "rock the 3FNC's world." asked for videos of the flight. "Now, the F20 may just be sufficient." and did say that he/she would need to run the simulation but was on the road and would need to run the simulation software.
Bottom line, I am pleased by the personal response to a question from a BAR who can't run the simulation software. One is conservative and the other liberal. Given that neither are completely wrong I'm still a bit confused. Obviously, what I should do is purchase an Aerotech F37W-M as recommended on the Apogee website, I don't feel like spending the $18.00. I am inclined to go with the G79, I have 80 acres and more open land around me.
I'm not starting a debate between Pemberton and Apogee, just making an observation about the art of motor selection and wondering if there are other opinions.