Thanks again Tapio. I thank I will have a great time with F1M.
James Alderson
To: Indoor_Construction_at_yahoogroups.com
From: tapio.linkosalo_at_iki.fi
Date: Mon, 22 Apr 2013 10:24:01 +0300
Subject: Re: [Indoor_Construction] Re: F1M Design
On Mon, Apr 22, 2013 at 12:50 AM, aldershine <aldershine_at_hotmail.com> wrote:
I'm catching on that getting the CG rearward enough is important with F1M. I may plan to go with a built-up prop to help reduce nose weight and I guess I can plan on a rather large stab.
To assist with design planning I guess my next step is to calculate moment weights for the models various components so that I will not have to put a stinger behind the tail to get the CG right.
I suppose it is. Then again, I have only flown short-fuselage F1M's more than 10 years ago, and without VP, so I cannot really tell what would there performance be.
For the reference, the component weights for my latest model are:
- front fuselage 820mg (plus some added boron later on)
- rear fuselage 400mg
- prop 475mg
- wing (200mm wide) 760mg
- tailplane (140mm wide at root, 430mm span flat) 400mg
- total 2850, but the added boron brought the weight to quite close to 3 grams.
The nose of the model is about 20-25mm long, and my CG lies at 120% of wing chord. Incidence is about 2 degrees (but this is really hard to measure accurately... :-) I started with a tail that was a bit larger in span (same size as my F1D tails), but as my decalage seemed to be too large, I built a new, slightly shorter tail. The stability is now quite on the edge, in heavier turbulence the model may stall both wing and tail and fall (flat) down a meter or more before acquiring forward momentum again. But in steadier conditions it seems to fly OK.
-Tapio-
Received on Mon Apr 22 2013 - 07:06:46 CEST