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  #11  
Old 05-08-2019, 03:08 PM
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Quote:
Originally Posted by timorley
I'm wondering where I'll wind up in total weight for the final rocket. The Estes catalog lists the Pershing 1A at 11.5 ounces (326.03 grams). Anybody have any real world weights for a finished Pershing? My BT-101 tube for this project weighs 88 grams. I'm going to set this up to accept the Estes E12-4, so I know that will require more nose weight than a D12-3 would. I believe there is roughly a 17.1 gram difference between a D12-3 and the E12-4 according to NAR data sheets.

If I don't forget, I'll weigh mine tonight. It's significantly underpowered with a D12-3. It's flight fishtailed and was considerably lower than my Centuri Saturn V, iirc. It was bad enough that I flew it one time and retired it immediately after. Back in those days I didn't fill spirals or prime under dark opaque paints like olive drab or artillery green. There was no heavy finishing work. The nose was just that heavy.
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  #12  
Old 05-08-2019, 03:51 PM
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You will have better flights on a full 40 n-sec E15/18 or E28/30 Aerotech Composite.
All the 24 and 29mm BP SU engines from Estes are what I would call "barely adequate" for anything classified as a "Maxi Brute"; case in point, the 1/45 Little Joe II has ONLY the E30 as a suggested motor; ZERO BP motors.
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  #13  
Old 05-08-2019, 04:07 PM
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I considered something more powerful, but you know, one of the most memorable rockets I had as a kid was my Maxi-Brute Honest John. Yeah, it barely lumbered off the pad under a D12-3, and there was that sometimes sick feeling in the pit of your stomach while you waited for the chutes to barely open just in time (they always did), but I loved it. It was always a crowd pleaser, I think because you could easily watch the whole flight close up. It was a real polar opposite to my desire to put the biggest engine I could fit into the smallest rocket approach.
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  #14  
Old 05-08-2019, 04:24 PM
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Quote:
Originally Posted by tbzep
If I don't forget, I'll weigh mine tonight. It's significantly underpowered with a D12-3. It's flight fishtailed and was considerably lower than my Centuri Saturn V, iirc. It was bad enough that I flew it one time and retired it immediately after. Back in those days I didn't fill spirals or prime under dark opaque paints like olive drab or artillery green. There was no heavy finishing work. The nose was just that heavy.

I appreciate it. I figured a D12-3 would be stretched to it's limits, which is why I'm thinking an E12-4 would be a better choice. I'm not looking to send this into orbit, but I do want to make sure I can have a safe reliable flight. Your data point will help.
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  #15  
Old 05-08-2019, 04:43 PM
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My Maxi-Honest John flew great on Estes D12-3 motors. If one thinks it is marginal on a D12, they haven't seen the Pershing on that motor!
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  #16  
Old 05-08-2019, 04:53 PM
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Quote:
Originally Posted by tbzep
My Maxi-Honest John flew great on Estes D12-3 motors. If one thinks it is marginal on a D12, they haven't seen the Pershing on that motor!

Yeah, I don't think I'd classify the Honest John was marginal to the point of being unsafe or having poor flight characteristics, didn't mean to give that impression. But in comparison it was low and slow compared to most rockets. It always worked and flew up straight as an arrow. But it always did worry me waiting for the chutes to open. :-) Maybe more because it was the pride of my fleet and I didn't want to see it crash versus it being in real jeopardy. I have a Maxi-Brute Honest John in the works on my bench too, but it's an Estes kit, not a clone.
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  #17  
Old 05-08-2019, 04:53 PM
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Quote:
Originally Posted by tbzep
My Maxi-Honest John flew great on Estes D12-3 motors. If one thinks it is marginal on a D12, they haven't seen the Pershing on that motor!


The Pershing sounds about like the Maxi X-Wing on a D12-3. It was a 'lob' at best. No time, really, for chutes to fully deploy before hitting the ground.

Next flight (and that was the last, 30 years ago) was on an Aerotech E. That was workable.


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  #18  
Old 05-08-2019, 04:57 PM
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Mine is 11.8 oz including the OEM recovery system...and a lot of dust from hanging from the ceiling.
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  #19  
Old 05-08-2019, 07:36 PM
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Quote:
Originally Posted by tbzep
Mine is 11.8 oz including the OEM recovery system...and a lot of dust from hanging from the ceiling.

Thank you!
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Tim

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  #20  
Old 05-11-2019, 01:41 AM
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I have all three lower fins printed and one upper fin. I did print the smaller scale version of the fin Leo provided. For better or worse, I decided to go with the larger, it visually looks more proportional with the larger lower fins. The larger version weighs 13 grams and the smaller 11 grams.
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"You know, it, uh, won't fly unless somebody pushes the button." From the movie October Sky.

I am SAM # 0167
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https://www.rocketryohio.com
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