X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 19 Mar 2014 08:07:55 -0400 Message-ID: X-Original-Return-Path: Received: from nm36-vm2.bullet.mail.bf1.yahoo.com ([72.30.238.138] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 6786233 for lml@lancaironline.net; Tue, 18 Mar 2014 20:40:43 -0400 Received-SPF: none receiver=logan.com; client-ip=72.30.238.138; envelope-from=n20087@yahoo.com Received: from [66.196.81.172] by nm36.bullet.mail.bf1.yahoo.com with NNFMP; 19 Mar 2014 00:40:07 -0000 Received: from [98.139.213.10] by tm18.bullet.mail.bf1.yahoo.com with NNFMP; 19 Mar 2014 00:40:07 -0000 Received: from [127.0.0.1] by smtp110.mail.bf1.yahoo.com with NNFMP; 19 Mar 2014 00:40:07 -0000 X-Yahoo-Newman-Id: 679675.1654.bm@smtp110.mail.bf1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: qMGZgwUVM1m44Otc_Wc4tl8tSIEBJPRHE.N6qZf30QSQ8IE bwcxLgDJi_e7ueRfM2GI3IdvLXCa0rJA.lOYHUmnR9iXGD3IAOYZZQDyhALN JCO0A0TdU7sJeXjZ1p8UgpMAWR1ptp12FpXhaAA.y8g6yYcy5RxiO.YB5y_p BvTfIVEr7Omx6zMtvZ6D.Kq1CeuU7H4sOT0otXUy3_1DEu39NKH_lH7RZYfk u_hpaTbiZaVY16JYYW8XPv0Ub8zPYgOAi0pUxN5KjGjqqZeCZiB3.0n5vz_d O7blWWCThqITlLv5PwAuWijwISxbKAsM5D11obVs828a7AwYMmDShHFrxXzS iKQ.yPYxzT3FOSS.Yvzo4kBnRzZSECBsMs3FLi7_sVas9jwV0hspIq.XI7d2 AsNAa5sLm0nunurDR2VAPXZIgwIWE5IQej8uskjp0MnBp.wq9EdNd5v8mc3_ OzJo4ERHQY_.0uqxRC9v7dieBu2k165C6.mDaOvND42ZLBBdgFROx0tKS3Iz Jmrc4neOd3jL1rh1Ykf.eR6TtghUxoyXUVuoiXAYzgRWgMXQJD676n98JS12 JOfK5.1K1t9KwVMQ7Lcd972X3AJZgB18ktyj5vTzRhKZp0YbKppDICgidk0j iDsa8tWz8SmiTtFu35NdybjaSXA-- X-Yahoo-SMTP: NQQt3c2swBAKSrExoA1eZuT7_w-- X-Rocket-Received: from [192.168.1.105] (n20087@24.254.183.50 with xymcookie [216.39.61.254]) by smtp110.mail.bf1.yahoo.com with SMTP; 18 Mar 2014 17:40:07 -0700 PDT Subject: Re: [LML] Re: Autopilot servos and L360 bobweight References: From: Tom Content-Type: multipart/alternative; boundary=Apple-Mail-CBDF5E8E-225B-4A29-8791-C24E16DD7CAE X-Mailer: iPad Mail (11B511) In-Reply-To: X-Original-Message-Id: <20332D07-C688-401D-80AA-1B436E9D74CC@yahoo.com> X-Original-Date: Tue, 18 Mar 2014 20:40:08 -0400 X-Original-To: Lancair Mailing List Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-CBDF5E8E-225B-4A29-8791-C24E16DD7CAE Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable John As Chris points out, the servo may need a little tuning to your mechanical s= ystem. Recently while installing/testing the g3x servos I found the default g= ain was set too high and with a little trial and error it was not too diffic= ult dial in. There are more scientific methods to achieving the same result= and having quite a good deal of experience at tuning control systems in a p= rofessional capacity I can say the trial and error method is probably the mo= st efficient in this particular setting. =20 I would not remove the bob weight, the 360 has lousy "feel" in pitch. As Ch= ris also points out the g force vs stick force curve is really horrible with= out it and you need the most cues at a time when you least expect it Tom Sent from my iPad > On Mar 18, 2014, at 3:14 PM, Chris Zavatson wro= te: >=20 > John, > I think you are mixing up the counterweight and the bob-weight. The count= erweight is indeed there to prevent flutter by mass balancing the control su= rface. Removing the bob-weight will reduce the stick force/g. Lancair expe= rimented with reducing or eliminating the bob-weight many years ago. I don'= t recall the details however. > Chris Zavatson > N91CZ > 360std > http://www.n91cz.net/=20 >=20 >=20 > On Tuesday, March 18, 2014 10:33 AM, Chris Zavatson wrote: > Jack, > The bob-weight changes the slope of the stick force gradient. It is alrea= dy very shallow. Removing the weight would make it even more so. =20 > What is the nature of the 'inconsistent' altitude hold, a long and slow me= andering (likely a static source lag issue) or a short and quick movement (l= ikely a gain or sensitivity issue). >=20 > Chris Zavatson > N91CZ > 360std > http://www.n91cz.com/ >=20 >=20 > On Tuesday, March 18, 2014 6:55 AM, Jack Dysart wrot= e: > My Tru Trak autopilot altitude hold is inconsistent, and opinions are that= the servo had difficulty working properly because of the mass of the bobwei= ght on the elevator idler arm. One possibility is to remove the weight and e= xpect more pitch sensitivity (lighter stick force) in turns. Has anyone fou= nd other alternatives? > What if the mass of the bobweight is reduced? > =20 > My servo is behind the seat and connected to a ring clamp on the elevator c= ontrol tube with a smaller, roughly parallel, rod with bearing ends. > =20 > Jack Dysart =20 >=20 >=20 >=20 >=20 --Apple-Mail-CBDF5E8E-225B-4A29-8791-C24E16DD7CAE Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
John

As Chris= points out, the servo may need a little tuning to your mechanical system. R= ecently while installing/testing the g3x servos I found the default gain was= set too high and with a little trial and error it was not too difficult dia= l in.  There are more scientific methods to achieving the same result a= nd having quite a good deal of experience at tuning control systems in a pro= fessional capacity I can say the trial and error method is probably the most= efficient in this particular setting.  

I wou= ld not remove the bob weight, the 360 has lousy "feel" in pitch.  As Ch= ris also points out the g force vs stick force curve is really horrible with= out it and you need the most cues at a time when you least expect it

Tom

Sent from my iPad

On Mar 1= 8, 2014, at 3:14 PM, Chris Zavatson <chris_zavatson@yahoo.com> wrote:

John,
I think you are mixing up the counterweight and the bob= -weight.  The counterweight is indeed there to prevent flutter by mass b= alancing the control surface.  Removing the bob-weight will reduce the s= tick force/g.  Lancair experimented with reducing or eliminating t= he bob-weight many years ago.  I don't recall the details however.=
Chris Zavatson
N91CZ
360std


On Tuesday, March 18, 2014 10:33 AM, Chris Zavatson <chris_zavatson@yahoo.com> wrote:
<= div style=3D"color: rgb(0, 0, 0); font-family: times new roman, new york, ti= mes, serif; font-size: 14pt; background-color: rgb(255, 255, 255);">
Jack,
The bob-weight changes the slope of the stic= k force gradient.  It is already very shallow.  Removing the weigh= t would make it even more so.  
What is the= nature of the 'inconsistent' altitude hold, a long and slow meandering= (likely a static source lag issue) or a short and quick movement (like= ly a gain or sensitivity issue).

<= /span>
Chris Zavatson
N91CZ
360std<= /div>


On Tuesday, March 18, 2014 6:55 A= M, Jack Dysart <jldysart1@gmail.co= m> wrote:
My Tru Trak autopilot altitude hold is incons= istent, and opinions are that the servo had difficulty working properly beca= use of the mass of the bobweight on the elevator idler arm.  One possib= ility is to remove the weight and expect more pitch sensitivity (lighter sti= ck force) in turns.  Has anyone found other alternatives?
What if the mass of the bobweight is reduced?<= /div>
 
My servo is behind the seat and connected to a ring clamp o= n the elevator control tube with a smaller, roughly parallel, rod with beari= ng ends.
 
Jack Dysart    


=20


=
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