[NSRCA-discussion] Rudder mix instead of right thrust?

[vicenterc at comcast.net]

Thanks Dean that was very good information.

Actually, I do the reverse as Chip Hyde explained (RCU).  I am copyin and pasting his mail below.  This has been working for me in several planes.  The Focus I was the one that got more benefits doing this.  I still leave the right right trust as it was before.  Any other got the same experience?  Here is:

"I run almost no right thrust in my planes and use the thottle to rudd mix at 2% left rudd. to throttle at idle. Thottle is the master rudd the slave. This makes the planes fly so much better when inverted at idle, they do not have that funny yaw through the corners. I have all but stopped using right thrust and do it all with the mix. What happens is the fin moves to the opposite side when inverted but the engine and prop don't know it, so the plane starts to yaw really bad due to spiraling slip stream. 

To set this up just go out and fly the plane straight away from yourself at full throttle and then go to idle and watch to see which way it yaws start with 2% and start it from half throttle on down. 

Trim it a full throttle with you rudder trim, and when you go to an idle if the plane yaws left you have to much mix, yaws right there's not enough. Have this screen up at take off and a buddy that can adjust it for you. Once you have it going nice and straight at idle and full go out and do a stall turn at the end of the box, on your way down do a half roll and exit inverted, you will be amazed how well it will go through that corner. 

Do that first before any other trimming. After that go with CG(45 degree upline 1/2 roll and it should stay on that line with little or no down elev.) then ail differential(1 Degree More up the Down) verticals(wing incidence .5-1 degree positive, then put the stab where ever it needs to go get the elevators to be neutral, you will at this time mix 1-2% down elevator with throttle for your down lines), and knife edge last (start with 5% up elevator with rudd.) 

Let me know how it goes and remember trim smarter not harder<G>        
 
                                             Chip Hyde"

Vicente



-------------- Original message -------------- 
From: "Dean Pappas" <d.pappas at kodeos.com> 

Hello Vicente,
The trimming adjustment procedure for right rudder with throttle couple I will describe was developed with the Excelleron that I reviewed for Model Aviation. I synthesized this method, based on the several different methods I heard described. As Jason said, some of them did not fly right. The Excelleron is a very good flier, and with a dependable muffled 120 two-stroke I would use it a low-hassle practice ship. Like most airplanes, it required about 2-3/4" of right thrust and a small amount of right rudder to make the plane trim normally. The predictable unwanted effects in spin entries and loops (especially the outsides) were present but not unusually bad.

So what I did was 
1) Set the rudder dead straight and not touch the rudder trim lever again.
Confirm that this is really the middle with repeated upright and inverted stalls/spin entries, to make suer the plane does not have a bias to either side.
2) reduce the right thrust to a "guess" setting that is enough for whatever throttle setting and speed you fly your normal level lines.
You test this with shallow climbs at 2/3 throttle,  and small loops at that same throttle. I ended up with about 1-3/4 degrees. 
3) Set up a throttle into rudder curve mix and keep the percentages at zero from idle up to 2/3 throttle. Then add a slop from there to full throttle,
and adjust those upper coupling ratios to get a straight vertical line.


Limitations: 
Never fly above 2/3 throttle in level flight.
Never push the throttle up too soon before pulling or pushing to a vertical.
Avoid sudden throttle changes

In other words, this is not appropriate if you have not mastered purposeful throttle management.

Hope this helps,
Dean P.


Dean Pappas 
Sr. Design Engineer 
Kodeos Communications 
111 Corporate Blvd. 
South Plainfield, N.J. 07080 
(908) 222-7817 phone 
(908) 222-2392 fax 
d.pappas at kodeos.com 
-----Original Message-----
From: vicenterc at comcast.net [mailto:vicenterc at comcast.net]
Sent: Monday, February 20, 2006 4:58 PM
To: NSRCA Mailing List; NSRCA Mailing List
Cc: Dean Pappas
Subject: Re: [NSRCA-discussion] Rudder mix instead of right thrust?


Dean,

Could you paste the article here?

Thanks,

Vicente Bortone

-------------- Original message -------------- 
From: "Dean Pappas" <d.pappas at kodeos.com> 

> I wrote about the throttle-rudder couple trimming procedure in FM about nine 
> months ago. 
> I also described the shortcomings for those pilots still learning optimal 
> throttle use. 
> Dean Pappas 
> 
> -----Original Message----- 
> From: nsrca-discussion-bounces at lists.nsrca.org on behalf of George 
> Miller 
> Sent: Sun 2/19/2006 11:08 AM 
> To: NSRCA Mailing List 
> Cc: 
> Subject: [NSRCA-discussion] Rudder mix instead of right thrust? 
> 
> 
> Somewhere I've seen a description of Jason's technique to set up rudder 
> mix instead of right engine thrust, but I can't find it. Could someone please 
> re-post this or re-iterate it. I can't believe I didn't save the message!-DOH! 
> 
> I can set up the mix in the transmitter...what I really want to know is 
> what starting percentages are reasonable, and how to fine tune the mix. 
> 
> thanks, 
> 
> George 
> 
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