Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > Weather-Cocked > Mission Control
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 10-24-2011, 04:38 PM
int3grate int3grate is offline
Junior Rocketeer
 
Join Date: Sep 2011
Posts: 6
Default D-Region Tomahawk Launch

Pictures:
http://gallery.kylenandnick.com/var...PG?m=1319492154
http://gallery.kylenandnick.com/var...PG?m=1319492241
http://gallery.kylenandnick.com/var...PG?m=1319492185

Video: http://www.youtube.com/watch?v=aDYSKT0dwcc

I launched my D-Region Tomahawk yesterday. Other than the 13 gram keychain camera attached, the rocket was a complete stock build, launched using an E9-6 engine.

I'm upset because the cheap rubber shock cord broke during ejection and the rocket careened into the ground. The believe an E9-6 engine is not the correct one to use for this model (although that's what the instructions said to use). I believe with an E9-4 engine, I would have had a better flight and the ejection charge would have fired closer to the apex of the flight.
Reply With Quote
  #2  
Old 10-24-2011, 07:02 PM
A Fish Named Wallyum A Fish Named Wallyum is offline
BP Mafia
 
Join Date: Mar 2005
Location: Ft. Thomas, KY
Posts: 8,596
Default

Looked like a great flight until ejection. I think you're right about the E9-4. Pretty big bird for a 6 second ejection charge. You might consider contacting Estes customer service about this.
__________________
Bill Eichelberger
NAR 79563

http://wallyum.blogspot.com/

I miss being SAM 0058

Build floor: Centuri Design Contest F-150 Hurricane Estes - Low Boom SST Semroc - Gee'Hod, Shrike, SST Shuttle

In paint: Canaroc Starfighter Scorpion Estes F-22 Air Superiority Fighter, Solar Sailer II Semroc Cyber III

Ready to fly: Estes - Multi-Roc, Solar Sailer II Semroc - Earmark, Snake Jumper
Reply With Quote
  #3  
Old 10-24-2011, 07:59 PM
blackshire's Avatar
blackshire blackshire is offline
Master Modeler
 
Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 6,507
Default

Quote:
Originally Posted by int3grate
-SNIP-
I'm upset because the cheap rubber shock cord broke during ejection and the rocket careened into the ground. The believe an E9-6 engine is not the correct one to use for this model (although that's what the instructions said to use). I believe with an E9-4 engine, I would have had a better flight and the ejection charge would have fired closer to the apex of the flight.
-SNIP-
Get thee some Kevlar cord! For a rocket of that weight, I'd use 400# Kevlar cord for the lower section of the shock cord, with 1/4" fabric/rubber elastic cord for the upper section of the shock cord. Kevlar and elastic are available from these rocket vendors (among others):

Apogee Components (see: www.apogeerockets.com )
Semroc Astronautics (see: www.semroc.com )
__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

Last edited by blackshire : 10-24-2011 at 08:00 PM. Reason: This ol' hoss done had to correct a typo.
Reply With Quote
  #4  
Old 10-24-2011, 09:10 PM
int3grate int3grate is offline
Junior Rocketeer
 
Join Date: Sep 2011
Posts: 6
Default

Quote:
Originally Posted by blackshire
Get thee some Kevlar cord! For a rocket of that weight, I'd use 400# Kevlar cord for the lower section of the shock cord, with 1/4" fabric/rubber elastic cord for the upper section of the shock cord. Kevlar and elastic are available from these rocket vendors (among others):

Apogee Components (see: www.apogeerockets.com )
Semroc Astronautics (see: www.semroc.com )


What do you mean? I should tie the elastic directly to the kevlar cord? Should I separate them with a swivel?

How should I attach the kevlar cord to the rocket? Using the same type of glue on mount Estes uses? I already removed the damage portion of the tube...
Reply With Quote
  #5  
Old 10-24-2011, 09:18 PM
A Fish Named Wallyum A Fish Named Wallyum is offline
BP Mafia
 
Join Date: Mar 2005
Location: Ft. Thomas, KY
Posts: 8,596
Default

Quote:
Originally Posted by int3grate
What do you mean? I should tie the elastic directly to the kevlar cord? Should I separate them with a swivel?

How should I attach the kevlar cord to the rocket? Using the same type of glue on mount Estes uses? I already removed the damage portion of the tube...


Tie the Kevlar around the motor tube behind the forward centering ring, then put a notch in the centering ring and glue the Kevlar loop to the motor tube and the point where it passes through the centering ring. Then knot the end together with the elastic. You can use a swivel to attach the elastic to the nose cone.
__________________
Bill Eichelberger
NAR 79563

http://wallyum.blogspot.com/

I miss being SAM 0058

Build floor: Centuri Design Contest F-150 Hurricane Estes - Low Boom SST Semroc - Gee'Hod, Shrike, SST Shuttle

In paint: Canaroc Starfighter Scorpion Estes F-22 Air Superiority Fighter, Solar Sailer II Semroc Cyber III

Ready to fly: Estes - Multi-Roc, Solar Sailer II Semroc - Earmark, Snake Jumper
Reply With Quote
  #6  
Old 10-25-2011, 02:23 AM
blackshire's Avatar
blackshire blackshire is offline
Master Modeler
 
Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 6,507
Default

Quote:
Originally Posted by int3grate
What do you mean? I should tie the elastic directly to the kevlar cord? Should I separate them with a swivel?

How should I attach the kevlar cord to the rocket? Using the same type of glue on mount Estes uses? I already removed the damage portion of the tube...
What Bill Eichelberger said above. These two-part Kevlar/elastic shock cords are standard in Quest Aerospace's kits (see: www.questaerospace.com [Quest President Bill Stine invented this shock cord in 1991]) and in Semroc Astronautics' kits (see: www.semroc.com ).
__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

Last edited by blackshire : 10-25-2011 at 02:24 AM. Reason: This ol' hoss done forgot somethin'.
Reply With Quote
  #7  
Old 10-25-2011, 05:49 PM
int3grate int3grate is offline
Junior Rocketeer
 
Join Date: Sep 2011
Posts: 6
Default

Quote:
Originally Posted by A Fish Named Wallyum
Looked like a great flight until ejection. I think you're right about the E9-4. Pretty big bird for a 6 second ejection charge. You might consider contacting Estes customer service about this.


I did, and they're sending my the parts I need to fix the rocket. Hopefully, with a little Kevlar and a different engine - it will fly perfectly
Reply With Quote
  #8  
Old 10-25-2011, 06:54 PM
PaulK PaulK is offline
BAR
 
Join Date: Nov 2005
Location: WI
Posts: 1,847
Default

Looked like it weather cocked quite a bit, that'll require a shorter delay. Was it windy? Was there rod whip?
__________________
Paul
If we weren't all crazy, we would go insane - Jimmy Buffett
NAR #87246 www.wooshrocketry.org
Reply With Quote
  #9  
Old 10-25-2011, 08:29 PM
int3grate int3grate is offline
Junior Rocketeer
 
Join Date: Sep 2011
Posts: 6
Default

Quote:
Originally Posted by PaulK
Looked like it weather cocked quite a bit, that'll require a shorter delay. Was it windy? Was there rod whip?


There was no wind. I didn't see any rod whip.
Reply With Quote
  #10  
Old 10-26-2011, 01:36 AM
blackshire's Avatar
blackshire blackshire is offline
Master Modeler
 
Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 6,507
Default

Quote:
Originally Posted by int3grate
I did, and they're sending my the parts I need to fix the rocket. Hopefully, with a little Kevlar and a different engine - it will fly perfectly
Excellent! Estes has exemplary customer service; I just note that Estes would avoid the necessity of "making it good" in cases like yours if they would just use Kevlar/elastic shock cords in their model rocket kits in the first place. Their rubber shock cords are okay in smaller, lighter rockets as long as they're provided in sufficiently long lengths (which Estes failed to do for many years, although they are providing longer shock cords in new-production rocket kits now that they are under new management), but Kevlar is more heat-resistant. Also, Kevlar can be used without the elastic cord in lightweight rockets that use BT-5/Series #5 and BT-20/Series #7 body tubes, as long as the Kevlar cord is long enough (18" - 24" or so).
__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR
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 12:49 AM.


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