Notices
Giant Scale Aircraft - General Discuss all other giant scale aircraft here.

1/4 scale chipmunk

Old 01-22-2011, 02:09 PM
  #1  
Junior Member
Thread Starter
 
Join Date: Oct 2004
Location: Warwickshire, UNITED KINGDOM
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
Default 1/4 scale chipmunk

I have just completed a 1/4 scale chipmunk manufactured by an english company from oxford in the uk .
This has been covered in litho with the rivet detail ,in RAF training colours .
Has anyone any ideas where the CofG should be ,I am working around the main wing spar but at 24 pounds dry weight would like to be sure .
Power from a z 38 with a wooden 20/10 prop 108inch span
any info welcome thanks all
Old 01-22-2011, 02:35 PM
  #2  
My Feedback: (159)
 
Join Date: Sep 2010
Location: GLEN ALLEN, VA
Posts: 331
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 1/4 scale chipmunk

As for the cg I would contact the manufacturer or the designer listed on the plans.
As for your engine choice in my opinion the plane will be under powered and heavy do to the engine you have chosen.Check out the weight of a DLE 30 or DLE 55 and you will reconsider. You can achieve a much higher engine to power ratio.The plane will have a signicant drop in its overall weight and actually need less power.
Yes I speak from experience.
I hope you find my comments helpful.
Old 01-22-2011, 04:13 PM
  #3  
 
Join Date: Feb 2003
Location: australia, AUSTRALIA
Posts: 54
Likes: 0
Received 2 Likes on 2 Posts
Default RE: 1/4 scale chipmunk

I have a 101" Super Chipmunk. It weighs 26lb 11oz. The designer recommended a CG of 28% mac. Mine flys very nicely at 31%. Is very aerobatic in the old style of aero's, even knife edge flight.
The engine is a Z 62. On a 21 x 10 prop it flys ok but the blades go ballistic and very noisy at top revs. It is much better on a 22 x 10.
Hope this helps
C de J

Old 01-23-2011, 06:22 AM
  #4  
Junior Member
Thread Starter
 
Join Date: Oct 2004
Location: Warwickshire, UNITED KINGDOM
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 1/4 scale chipmunk

thanks Glen but the manufacturers no longer exist allthough the model is superb
hence the reason for the enquiry
I had thought about another engine but the aircraft was produced before exotic engines like the DLE were available

the engine of choice was the agricultural z38
thanks again Richard
Old 01-23-2011, 09:49 AM
  #5  
My Feedback: (20)
 
Join Date: Oct 2002
Location: Cincinnati, OH,
Posts: 973
Likes: 0
Received 11 Likes on 10 Posts
Default RE: 1/4 scale chipmunk

Richard, plug the numbers for your model into this spread sheet. Use 10% stability margin to start. It has given good results for me.
http://adamone.rchomepage.com/cg_calc.htm
Chuck
Old 01-23-2011, 11:53 AM
  #6  
Junior Member
Thread Starter
 
Join Date: Oct 2004
Location: Warwickshire, UNITED KINGDOM
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 1/4 scale chipmunk

Chuck , you are a god , thank you what a fantastic web page .
Just crunching the numbers in, will keep you informed
thanks again
Richard

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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On


Thread Tools
Search this Thread

Contact Us - Manage Preferences Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.