Re: Re: 40% Stab size or 20%?

From: Bill Gowen <wdgowen_at_gmail.com>
Date: Sat, 23 Oct 2010 20:27:31 -0400

Kang and I have been kicking around the motor weight problem in the spreadsheet. My version started out as June, 2000 and came from Bernie. In the Hunt program the optimum motor weight is 1.4 x model weight which was good for 65cm F1D. This seems to be used in unusual ways in the program. I haven't gotten very far with the change yet.

One thing that I have done is alter the way the CG is calculated by letting you input MS length and CG so that a MS that is longer than the hook to hook distance gets its effect on the model CG calculated correctly. I've done the same sort of thing fpr the prop, rudder (if any) and the tailboom. Also the CG will be shown with and without rubber.

For my last round of motor testing (LPP and F1L) I figured out a work around for varying the motor weight's effect on flight time but it would be great to be able to do this directly in the program. I'm actually not so much interested in the flight time prediction being accurate. I just want a number - any number - that tells me whether a design change has a positive or negative effect on duration. (and of course stability)

----- Original Message -----
  From: Don Slusarczyk
  To: Indoor_Construction_at_yahoogroups.com
  Sent: Saturday, October 23, 2010 6:11 PM
  Subject: Re: [Indoor_Construction] Re: 40% Stab size or 20%?


    
  The wing Cl is fixed in the sheet I posted the link to, it is 0.8 You
  have to monitor the stab CL if it gets above ~0.5 then you will most
  likely not have a flyable model configuration. I did find another
  version where I made wing Cl a variable.

  Don

> Which row is Cl in? I see Coeff of lift for the stab in row 36, but I assume you are talking about the Cl for the wing, or maybe even the total Cl?
>



  
Received on Sat Oct 23 2010 - 17:27:38 CEST