Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > Work Bench > Projects
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 05-10-2005, 03:02 PM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,355
Talking Cherokee Double-D

All,

Back in August of 2004, on the OldRockets list, we had this discussion about a two-stage version of the Cherokee-D. Our general consensus was to start with the C-C Express...

I've sent Scott a set of modified decals and a set of fin templates to build one version of this model. This version has the booster fins reduced in size to 85% of the originals. The booster fin decals on the new sheet are reduced accordingly.

Thanks to James Gartrell for his original "Cherokee DD" name decal. The decal sheet I created borrows from his pattern, but uses the "D" of the original Cherokee-D. Since I can now post the images here on the Forum, I'll attach them to this message so anyone who wants a set can try it out...

The decal sheet here is in JPG format, but the version I sent to Scott is a TIF, with perhaps a bit more resolution.

Also included is a copy of an alignment guide that works well. Attach the pattern to a thicker piece of cardboard and remove everything inside the outline (you may have to use some sandpaper to adjust the opening...), and it will hold the fins in their correct positions while the glue dries.

Enjoy!


Craig McGraw
Attached Thumbnails
Click image for larger version

Name:  Cherokee DD Alignment Guide.jpg
Views: 345
Size:  75.6 KB  Click image for larger version

Name:  Cherokee DD Decal Sheet.jpg
Views: 320
Size:  436.5 KB  
Attached Files
File Type: tif Cherokee DD Fins.tif (65.3 KB, 320 views)
Reply With Quote
  #2  
Old 05-10-2005, 03:21 PM
Eagle3's Avatar
Eagle3 Eagle3 is offline
Administrator
 
Join Date: Jun 2004
Location: Manchester,MI
Posts: 1,242
Default

Why are the booster fins reduced and not the upper stage? I don't recall the discussion on oldrockets, so I don't know the history.
__________________
Quando Omni Flunkus Moritati
Reply With Quote
  #3  
Old 05-10-2005, 03:42 PM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,355
Talking

Quote:
Originally Posted by Eagle3
Why are the booster fins reduced and not the upper stage? I don't recall the discussion on oldrockets, so I don't know the history.


I had to look hard to find the thread, myself. Mid-August, message numbers between 21500 and 22000...

There were several suggested fin patterns in the discussions, but the thread died out without a final accepted booster pattern. One plan version used a set of fins similar to the main fins of the #2174 Polaris, while another suggested enlarging the original fins to use for the booster.

The reduced-area "booster" fin idea is not uncommon, and has been used by several Estes' kit designs, including the Clipper, the SARK, and the Guardian. I saw this version as just one more design in the list of possible solutions.


Craig...
Reply With Quote
  #4  
Old 05-10-2005, 03:47 PM
Eagle3's Avatar
Eagle3 Eagle3 is offline
Administrator
 
Join Date: Jun 2004
Location: Manchester,MI
Posts: 1,242
Default

Gotcha. The SARK and Clipper came to mind when I visualized this. I just thought that with two 24mm Ds that one might want the added fin area aft, especially if you build the original shorter tube Cherokee D. I'll have to rocksim it and see how it looks. Thanks for the image uploads!
__________________
Quando Omni Flunkus Moritati
Reply With Quote
  #5  
Old 05-10-2005, 03:56 PM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,355
Talking

Quote:
Originally Posted by Eagle3
Gotcha. The SARK and Clipper came to mind when I visualized this. I just thought that with two 24mm Ds that one might want the added fin area aft, especially if you build the original shorter tube Cherokee D. I'll have to rocksim it and see how it looks. Thanks for the image uploads!


Since we started with the CC Express kit, this offered the chance to do a long-body version (full 18" BT-55 tube), so the reduced fin area really shouldn't be a problem. The decal I sent uses the modern Estes logo, making this version more like an extension of the #1247 version rather than the "K" version.

I need to sim up the short-body version with this booster, but I still think the stability is OK. At the very least, the short-body version might need some weight added, but probably not much. The original Cherokee-D is a very stable design as-is...


Craig...
Reply With Quote
  #6  
Old 05-10-2005, 10:10 PM
ScaleNut's Avatar
ScaleNut ScaleNut is offline
Craftsman
 
Join Date: Apr 2005
Location: Heart of the South
Posts: 269
Default

either way , I like to make sure the booster is unstable enough to tumble ,
Reply With Quote
  #7  
Old 05-11-2005, 12:39 AM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,355
Thumbs up

Quote:
Originally Posted by CPMcGraw
I need to sim up the short-body version with this booster, but I still think the stability is OK. At the very least, the short-body version might need some weight added, but probably not much. The original Cherokee-D is a very stable design as-is...

Craig...


OK, the sim is in! (AGAIN)

In fact, if you've already read this message once, I've updated the RKT file. Found something out that I didn't notice before, and had to correct it. The design is NOT naturally stable in two-stage mode, and DOES need some weight in the nose (0.25 oz at the tip). This gives the full-up rocket a 1.0 calibre margin.

The new RockSim 8 [Beta 3] gives me a 2155' altitude for this bad boy, using a D12-0/D12-7 combination. This is for the LONG-BODY version. Deployment is within a foot or two of apogee!

I'd say this confirms the stability of the (corrected) design...

ZIPped RKT file is attached...

Craig McGraw
Attached Files
File Type: zip CDD Project.zip (6.1 KB, 277 views)

Last edited by CPMcGraw : 05-11-2005 at 01:07 AM.
Reply With Quote
  #8  
Old 05-11-2005, 11:19 AM
Tweener's Avatar
Tweener Tweener is offline
Out To Launch
 
Join Date: Mar 2005
Location: Ottawa, Ohio
Posts: 281
Default

Quote:
Originally Posted by CPMcGraw
The decal sheet I created borrows from his pattern, but uses the "D" of the original Cherokee-D. Since I can now post the images here on the Forum, I'll attach them to this message so anyone who wants a set can try it out...

Craig,

Just so Marvel Comics doesn't see the sheet. Those D's look very similar to the front of the costume on a certain blind lawyer's red, horned alter ego. They might make you put a TM or something on it.
__________________
John Lance Ladd
Yoyodyne Propulsion Systems
Grovers Mill, NJ
Established 1938
lladd.netau.net
Reply With Quote
  #9  
Old 05-11-2005, 12:22 PM
CPMcGraw's Avatar
CPMcGraw CPMcGraw is offline
BARCLONE Rocketry
 
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,355
Lightbulb

Quote:
Originally Posted by Tweener
Craig,

Just so Marvel Comics doesn't see the sheet. Those D's look very similar to the front of the costume on a certain blind lawyer's red, horned alter ego. They might make you put a TM or something on it.


Lance,

That would be a coincidence, believe me. I'm not a comic book collector, so I wouldn't be familiar with the character you've described. I was simply using the existing "D" insignia from the original decal. Overlapping "D"s are seen in other artwork, so I think the context has a lot to do with it...


Craig...
Reply With Quote
  #10  
Old 05-11-2005, 07:35 PM
Tweener's Avatar
Tweener Tweener is offline
Out To Launch
 
Join Date: Mar 2005
Location: Ottawa, Ohio
Posts: 281
Default

Quote:
Originally Posted by CPMcGraw
That would be a coincidence, believe me. I'm not a comic book collector, so I wouldn't be familiar with the character you've described. I was simply using the existing "D" insignia from the original decal. Overlapping "D"s are seen in other artwork, so I think the context has a lot to do with it...

I was refering to DareDevil, good logo shot here: http://www.emerchandise.com/product...0003/s.LhsTx4hg . I didn't think it was intentional, it just immediately brought him to mind for me. (I was also attempting to make fun of copyright and trademark holders overzealous tendencies to litigation as well. Watch out for the brassiere manufacturers! )
__________________
John Lance Ladd
Yoyodyne Propulsion Systems
Grovers Mill, NJ
Established 1938
lladd.netau.net
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 11:33 AM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe 1998-2019