Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > Work Bench > 3D Printing Asylum
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #11  
Old 05-08-2019, 02:08 PM
tbzep's Avatar
tbzep tbzep is offline
Dazed and Confused
 
Join Date: Mar 2005
Location: TN
Posts: 11,610
Default

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.
__________________
I love sanding.
Reply With Quote
  #12  
Old 05-08-2019, 02:51 PM
ghrocketman's Avatar
ghrocketman ghrocketman is offline
President, MAYHEM AGITATORS, Inc.
 
Join Date: Jul 2005
Location: Nunya Bizznuss, Michigan
Posts: 13,443
Default

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.
__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL
, if you have to ask what is "NORMAL" , you probably aren't !

Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !
Reply With Quote
  #13  
Old 05-08-2019, 03:07 PM
timorley's Avatar
timorley timorley is offline
That 70's Rocketeer
 
Join Date: Jan 2007
Location: Bright, Indiana
Posts: 397
Default

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.
__________________
Tim

"You know, it, uh, won't fly unless somebody pushes the button." From the movie October Sky.

I am SAM # 0167
NAR 98303 Southwestern Ohio Rocketry Association (SORA) #624
https://www.rocketryohio.com
Reply With Quote
  #14  
Old 05-08-2019, 03:24 PM
timorley's Avatar
timorley timorley is offline
That 70's Rocketeer
 
Join Date: Jan 2007
Location: Bright, Indiana
Posts: 397
Default

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.
__________________
Tim

"You know, it, uh, won't fly unless somebody pushes the button." From the movie October Sky.

I am SAM # 0167
NAR 98303 Southwestern Ohio Rocketry Association (SORA) #624
https://www.rocketryohio.com
Reply With Quote
  #15  
Old 05-08-2019, 03:43 PM
tbzep's Avatar
tbzep tbzep is offline
Dazed and Confused
 
Join Date: Mar 2005
Location: TN
Posts: 11,610
Default

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!
__________________
I love sanding.
Reply With Quote
  #16  
Old 05-08-2019, 03:53 PM
timorley's Avatar
timorley timorley is offline
That 70's Rocketeer
 
Join Date: Jan 2007
Location: Bright, Indiana
Posts: 397
Default

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.
__________________
Tim

"You know, it, uh, won't fly unless somebody pushes the button." From the movie October Sky.

I am SAM # 0167
NAR 98303 Southwestern Ohio Rocketry Association (SORA) #624
https://www.rocketryohio.com
Reply With Quote
  #17  
Old 05-08-2019, 03:53 PM
Earl's Avatar
Earl Earl is offline
Apollo Nut
 
Join Date: Dec 2006
Posts: 4,894
Default

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.


Earl
__________________
Earl L. Cagle, Jr.
NAR# 29523
TRA# 962
SAM# 73
Owner/Producer
Point 39 Productions

Rocket-Brained Since 1970
Reply With Quote
  #18  
Old 05-08-2019, 03:57 PM
tbzep's Avatar
tbzep tbzep is offline
Dazed and Confused
 
Join Date: Mar 2005
Location: TN
Posts: 11,610
Default

Mine is 11.8 oz including the OEM recovery system...and a lot of dust from hanging from the ceiling.
Attached Thumbnails
Click image for larger version

Name:  20190508_155149.resized.jpg
Views: 60
Size:  252.4 KB  
__________________
I love sanding.
Reply With Quote
  #19  
Old 05-08-2019, 06:36 PM
timorley's Avatar
timorley timorley is offline
That 70's Rocketeer
 
Join Date: Jan 2007
Location: Bright, Indiana
Posts: 397
Default

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!
__________________
Tim

"You know, it, uh, won't fly unless somebody pushes the button." From the movie October Sky.

I am SAM # 0167
NAR 98303 Southwestern Ohio Rocketry Association (SORA) #624
https://www.rocketryohio.com
Reply With Quote
  #20  
Old 05-11-2019, 12:41 AM
timorley's Avatar
timorley timorley is offline
That 70's Rocketeer
 
Join Date: Jan 2007
Location: Bright, Indiana
Posts: 397
Default

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.
Attached Thumbnails
Click image for larger version

Name:  Pershing1AUpperFin.jpg
Views: 51
Size:  120.4 KB  
__________________
Tim

"You know, it, uh, won't fly unless somebody pushes the button." From the movie October Sky.

I am SAM # 0167
NAR 98303 Southwestern Ohio Rocketry Association (SORA) #624
https://www.rocketryohio.com
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -5. The time now is 06:36 AM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe © 1998-2024