SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Dec 28, 2012, 09:24 PM
Registered User
United States, TX, League City
Joined Jun 2008
368 Posts
Wings got new AoA
hi2nr is offline Find More Posts by hi2nr
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 28, 2012, 10:58 PM
Registered User
maurice076's Avatar
United States, MI, Warren
Joined Aug 2011
642 Posts
Hi2nr coming along nicely you'll be done in no time.
maurice076 is offline Find More Posts by maurice076
Reply With Quote
Old Dec 29, 2012, 12:01 AM
Registered User
United States, TX, League City
Joined Jun 2008
368 Posts
I might have hit a wall, how much aileron surface do I need? Lol
I think I will have to do a mixing like rudder to aileron or something
hi2nr is offline Find More Posts by hi2nr
Reply With Quote
Old Dec 29, 2012, 12:22 AM
Registered User
maurice076's Avatar
United States, MI, Warren
Joined Aug 2011
642 Posts
I found that mixing them results in a better turn than me trying to do it.
maurice076 is offline Find More Posts by maurice076
Reply With Quote
Old Dec 29, 2012, 12:56 AM
Registered User
United States, TX, League City
Joined Jun 2008
368 Posts
I guess I'll try scale ailerons and elevators and enlarge as needed
hi2nr is offline Find More Posts by hi2nr
Reply With Quote
Old Dec 29, 2012, 01:49 AM
Registered User
United States, TX, League City
Joined Jun 2008
368 Posts
Glide test went exceptionally well, much better than expected so from what I see, it'll need very little throttle to stay afloat
hi2nr is offline Find More Posts by hi2nr
Reply With Quote
Old Dec 29, 2012, 05:12 AM
Registered User
Zurich
Joined Apr 2006
4,012 Posts
da Vinci

Quote:
Originally Posted by hi2nr View Post
Wings got new AoA
Pretty, but you've apparently only adjusted the roots! The TIPS need to be at the [even approx.] right AoA for them, smoothly changing from the roots on out. Normally when you hand-twist the wing, the structure itself will create the right transition along the entire wing. Just look at the side view photos I posted above and twist your wings ....

If you don't, or are afraid to try [the process can be done in steps, each of which is reversible], the wing-tail system will average-out the AoA, and the roots will be at too LOW an AoA for optimal L/D [+ power req., stability & maneuverability] and the tips will be at too HIGH an AoA, and will like to tip-stall unless you fly faster than needed at a then higher minimum speed.

With even approx. correct AoA's throughout the wing [they MUST vary smoothly from root to tip!], the low end speed will be lower and the high end, higher.

You can use less powerful motors, smaller LIPO, etc.

L. da Vinci said, in presumably Medieval Italian, "Flying is not particularily difficult ... but it is intolerant of the slightest mistake".

He knew something ....


Lee
xlcrlee is offline Find More Posts by xlcrlee
Reply With Quote
Old Dec 29, 2012, 05:20 AM
Registered User
Zurich
Joined Apr 2006
4,012 Posts
Boeing

their engineers know something too

reposting photos [re: washout NECESSARY for best flight, in ANY scale]


xlcrlee is offline Find More Posts by xlcrlee
Reply With Quote
Old Dec 29, 2012, 11:04 AM
Registered User
United States, TX, League City
Joined Jun 2008
368 Posts
I guess let the twisting begin lol
hi2nr is offline Find More Posts by hi2nr
Reply With Quote
Old Dec 29, 2012, 01:22 PM
Registered User
Zurich
Joined Apr 2006
4,012 Posts
Quote:
Originally Posted by hi2nr View Post
I guess let the twisting begin lol
"Good Answer"


hints, re: washout or any wing adjustment-check >

1. stand in a direct line behind the plane and use ONE eye to make sure both wings are exactly the same

2. heat both the top and bottom surfaces, either quickly from top to bottom & back, or head-on, and/or in flying airflow direction, and hold in position till cool > when at the melting point [dangerous ground], you'll get the distinct Styrene smell!

an advantage of heating the surface is that it toughens the skin like a factory heat-formed part, adding strength
xlcrlee is offline Find More Posts by xlcrlee
Reply With Quote
Old Dec 29, 2012, 05:19 PM
Registered User
United States, TX, League City
Joined Jun 2008
368 Posts
Maiden was a success! It didn't like the wind much but flew. So now it's time to make adjustments as needed to get more performance
hi2nr is offline Find More Posts by hi2nr
Reply With Quote
Old Dec 29, 2012, 05:30 PM
Registered User
Zurich
Joined Apr 2006
4,012 Posts
Quote:
Originally Posted by hi2nr View Post
Maiden was a success! It didn't like the wind much but flew. So now it's time to make adjustments as needed to get more performance
Let us know the effect of any washout you will put in, and if the CG can then be moved back. Washout adds stability fore-aft also and moving the CG rearward in a stable aircraft increases L/D and wind penetration [note: if the horizontal tail was trimmed perfectly before, for dead air, you might have to reset it, depending on where the plane was, relative to min sink and max L/D].

Awaiting your results ....

xlcrlee is offline Find More Posts by xlcrlee
Reply With Quote
Old Dec 29, 2012, 05:33 PM
Registered User
United States, TX, League City
Joined Jun 2008
368 Posts
Quote:
Originally Posted by xlcrlee View Post
Let us know the effect of any washout you will put in, and if the CG can then be moved back. Washout adds stability fore-aft also and moving the CG rearward in a stable aircraft increases L/D and wind penetration [note: if the horizontal tail was trimmed perfectly before, for dead air, you might have to reset it, depending on where the plane was, relative to min sink and max L/D].

Awaiting your results ....

Your advice helped a lot, I was out at the field twisting the wings and ended up following the air foil similar to my larger 737, elevators I had to change the angle a bit as it kept flying as if it was nose heavy but it was just the elevator. Power off glides were pretty awesome. WOT speeds were running speeds so its no speed demon
hi2nr is offline Find More Posts by hi2nr
Reply With Quote
Old Dec 29, 2012, 05:49 PM
Registered User
Zurich
Joined Apr 2006
4,012 Posts
Try adding downthrust!

The airflow in front of the motors in this position comes up from the bottom, so downthrust actually increases effective power in this case.

.... also means you can move the CG even farther back while maintaining stability and increasing L/D

Note the goose's head/neck below > it is following the airflow
xlcrlee is offline Find More Posts by xlcrlee
Reply With Quote
Old Dec 29, 2012, 06:02 PM
Registered User
Zurich
Joined Apr 2006
4,012 Posts
re: downthrust

Look at the jet engine intake angles, and note that the outboard engines are set to take in air approaching from a steeper up-angle [outboard inlets more downturned > relates to my washout "tirade" ].

Your small model should need even more downturn [higher AoA].


L
xlcrlee is offline Find More Posts by xlcrlee
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log 747-8i Build rlebaron RC Airliners (Commercial, Cargo, Troop Carrier) 210 Feb 25, 2014 06:45 PM
Gallery Ultra micro 5g Boeing 747 mrexcel Scratchbuilt Indoor and Micro Models 17 Oct 02, 2013 04:50 PM
Discussion Late 747 JAL cargo build w747 RC Airliners (Commercial, Cargo, Troop Carrier) 26 Dec 18, 2012 11:04 PM
Idea Dual Thrust IR Micro Boeing 747 Electronick RC Airliners (Commercial, Cargo, Troop Carrier) 19 Oct 24, 2012 02:26 AM
Discussion Build micro-quad from micro-heli spare parts midelic Multirotor Talk 1 Apr 26, 2012 04:46 PM