Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > BARCLONE > Designer's Studio
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 02-19-2010, 11:07 PM
Feyd's Avatar
Feyd Feyd is offline
Master Modeler
 
Join Date: Feb 2010
Location: San Antonio, TX
Posts: 676
Default

Thanks all for your comments. I've been thinking about this design all day (I was bored don't you know) and I'm seriously considering taking it down to 18mm engines. They're cheaper and I'm not ready to try certification yet.

Also, I've written to three rocket companies about the rocket. So far two have responded. Once I get the design solidified I'll post an update.

Thanks again!
Reply With Quote
  #12  
Old 03-03-2010, 10:26 PM
Feyd's Avatar
Feyd Feyd is offline
Master Modeler
 
Join Date: Feb 2010
Location: San Antonio, TX
Posts: 676
Default

No update on the Six-Shooter (I'm redesigning) but I do have something else I'm currently building.

I call it the "Sky Breaker" - terrible name I know - but it's essentially a double-length Sunward SkyBender. It'll be about 70" tall and will fly on three D12-5s. I've run it in Rocksim and it says "overstable" and flies to almost 1000 ft.

As soon as I get it built and flown I'll post pictures.

I'd appreciate any thoughts.
Attached Files
File Type: rkt SkyBender Upscale.rkt (163.2 KB, 68 views)
Reply With Quote
  #13  
Old 03-03-2010, 11:50 PM
mycrofte's Avatar
mycrofte mycrofte is offline
Trust me, it'll work!
 
Join Date: Mar 2009
Location: Illinois
Posts: 1,729
Default

Stability?!?

I consider whirling loops of death part of the design process...
Reply With Quote
  #14  
Old 03-04-2010, 12:16 AM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
Exclamation

Quote:
Originally Posted by Feyd
No update on the Six-Shooter (I'm redesigning) but I do have something else I'm currently building.

I call it the "Sky Breaker" - terrible name I know - but it's essentially a double-length Sunward SkyBender. It'll be about 70" tall and will fly on three D12-5s. I've run it in Rocksim and it says "overstable" and flies to almost 1000 ft.

As soon as I get it built and flown I'll post pictures.

I'd appreciate any thoughts.


Feyd,

I'm looking the "Sky Breaker" design over, and I've altered the file a bit based on what your 2D line drawing indicated. I hope I'm reading this right - The model is supposed to have the three engine tubes exposed between the forward and aft sections, similar to the Custom Landviper. However, RockSim wasn't behaving properly and was showing a solid tube where it should have been just a "filler".

The new drawing rectifies the problem with a pod for the aft section, and three continuous 36.5" BT-50's for the engine tubes. I included a pair of couplers in each tube to trim out the weight (see the new file).

Either you're a time-tested expert in rocket design and just keeping it a secret, or you're one of the luckiest guesstimators I've seen yet! This new design hits the ULTIMATE SWEET SPOTS for each of the engine combinations in a way I've never experienced by ANY design before.

Also, I trimmed out some mass from the nose cone by reducing the wall thickness down to 0.05", which seems more likely than having it 0.125" thick. This brought the calculated weight down to just under your 'user override' weight. It's still a thick-skinned nose cone.

Specs:

Length: 70.15"
Diameter: 2.6" (BT-80)
Weight: 3.74 oz (empty)
Fin Span: 10.60"


(3) A8-3.........193'......Dv <2 FPS......28" launch guide required
(3) B6-4.........396'......Dv <3 FPS......25" launch guide required
(3) C6-5.........759'......Dv <3 FPS......25" launch guide required
(3) D12-5.......1120'......Dv <1 FPS......26" launch guide required
(3) E9-6........1697'......Dv <1 FPS......31" launch guide required
(3) E15W-7......2087'......Dv <3 FPS......13" launch guide required
(3) F21W-8......2391'......Dv <1 FPS......10" launch guide required


Keep tossing up ideas like this, and you'll get recognized very quickly!
Attached Thumbnails
Click image for larger version

Name:  SkyBender Upscale Mk II 2D.jpg
Views: 87
Size:  97.5 KB  Click image for larger version

Name:  SkyBender Upscale Mk II 3D.jpg
Views: 114
Size:  46.7 KB  
Attached Files
File Type: rkt SkyBender Upscale Mk II.rkt (116.3 KB, 94 views)
__________________
Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635
Reply With Quote
  #15  
Old 03-04-2010, 10:07 PM
Feyd's Avatar
Feyd Feyd is offline
Master Modeler
 
Join Date: Feb 2010
Location: San Antonio, TX
Posts: 676
Default

Well I've been dreaming up rocket ideas for quite a long time and even entered the Estes contests a *really long time ago* (never won anything) but I wouldn't call myself anything like time-tested :-)

Essentially I took the Sunward Skybender and doubled everything so I had a really good base to start with. My Skybender has flown a couple of times and I really like it alot. I've built most of the new rocket already, just need to finish the top and cut out the fins. Then paint.

I do have a question though.... how far does an ejection charge travel? The rocket is about 5' 8" tall. Since there are several regular model rockets out there that are much taller, I assume I won't have a problem with the ejection charge ejecting the parachute. I was thinking of putting a BT-80 baffle in there, but wasn't sure if it was necessary.

Thanks!
Reply With Quote
  #16  
Old 03-04-2010, 11:32 PM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
Default

Quote:
Originally Posted by Feyd
Well I've been dreaming up rocket ideas for quite a long time and even entered the Estes contests a *really long time ago* (never won anything) but I wouldn't call myself anything like time-tested :-)

Essentially I took the Sunward Skybender and doubled everything so I had a really good base to start with. My Skybender has flown a couple of times and I really like it alot. I've built most of the new rocket already, just need to finish the top and cut out the fins. Then paint.

I do have a question though.... how far does an ejection charge travel? The rocket is about 5' 8" tall. Since there are several regular model rockets out there that are much taller, I assume I won't have a problem with the ejection charge ejecting the parachute. I was thinking of putting a BT-80 baffle in there, but wasn't sure if it was necessary.

Thanks!


If you were trying to get by on just one charge, you might be in trouble. But you have three charges going off in this design. It ***should*** be enough to pressurize the tube and toss the laundry. Also, since the model has such a low Dv, the aerodynamic resistance to the ejection is much less. This is one of the important reasons we stress keeping the Dv (Velocity at Deployment) as low as possible. You did good, Feyd! All of these combinations are less than 5 FPS at deployment, meaning it's just barely moving when it blows. Little to no resistance at all.

Baffles have their place, but so does a good handful of dog barf (shredded newspaper insulation)...

Keep up the design work!
__________________
Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635
Reply With Quote
  #17  
Old 03-05-2010, 11:45 PM
Feyd's Avatar
Feyd Feyd is offline
Master Modeler
 
Join Date: Feb 2010
Location: San Antonio, TX
Posts: 676
Default

Thanks.

One final problem / request. I need to put 5 fins on the BT-80 at the base of the Sky Breaker. Does anyone have a template/wrap I can use? Maybe a location where such things are kept?

Almost ready for paint!
__________________
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Dale Marshall, San Antonio Texas
NAR #90990
Semroc SAM #083

BAR Since 2008
Enjoying model rocketry since 1977.
The Spotted Dragon
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Reply With Quote
  #18  
Old 03-06-2010, 09:23 AM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
Default

Quote:
Originally Posted by Feyd
Thanks.

One final problem / request. I need to put 5 fins on the BT-80 at the base of the Sky Breaker. Does anyone have a template/wrap I can use? Maybe a location where such things are kept?

Almost ready for paint!


I draw up my own patterns for each model using Corel Draw. What I like are patterns that allow me to hold the fin in place while the glue dries. These patterns have a slot for the fin to fit inside, and it takes two to keep the fin aligned correctly.

The general arrangement is a circle with fin slots radiating outward...
__________________
Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635
Reply With Quote
  #19  
Old 03-06-2010, 11:35 AM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
Default

Feyd,

Would you mind if I posted this design in our "official" BARCLONE lineup?
__________________
Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635
Reply With Quote
  #20  
Old 03-06-2010, 02:50 PM
Feyd's Avatar
Feyd Feyd is offline
Master Modeler
 
Join Date: Feb 2010
Location: San Antonio, TX
Posts: 676
Default

Sure, no problem. Thanks!

I'm hoping to finish the fins at least this week (out of town right now) and hopefully fly it soon. I'm really looking forward to seeing if it'll fly like it's supposed to.
__________________
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Dale Marshall, San Antonio Texas
NAR #90990
Semroc SAM #083

BAR Since 2008
Enjoying model rocketry since 1977.
The Spotted Dragon
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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 11:12 PM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe 1998-2020