X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 21 May 2014 08:54:06 -0400 Message-ID: X-Original-Return-Path: Received: from nm32-vm3.bullet.mail.bf1.yahoo.com ([72.30.239.139] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 6882358 for lml@lancaironline.net; Tue, 20 May 2014 18:57:52 -0400 Received-SPF: pass receiver=logan.com; client-ip=72.30.239.139; envelope-from=n20087@yahoo.com Received: from [66.196.81.174] by nm32.bullet.mail.bf1.yahoo.com with NNFMP; 20 May 2014 22:57:18 -0000 Received: from [98.139.211.196] by tm20.bullet.mail.bf1.yahoo.com with NNFMP; 20 May 2014 22:57:18 -0000 Received: from [127.0.0.1] by smtp205.mail.bf1.yahoo.com with NNFMP; 20 May 2014 22:57:18 -0000 X-Yahoo-Newman-Id: 518990.37430.bm@smtp205.mail.bf1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: hvoGo.kVM1m7NdpEIqtpsM2CIepGgpxTdPzFyzqRg7OHsGR 3YNrmjRyrGLXhgTquYPlNmcCX6fGJ6vkxDDWHrxuWScPSF0FWM_y90eFtkyu yw_NBE4KOoW8oYzNWQGZRqiWdwN8S5hBJ6DvCsHcSAXkVUvrWeeLC0R_268l 0_cJRdEWVwuQufJc.grsb_k6eAZ9e.OMpIHLcRDa07kH7CJxhVKvMT13HbDY .lTKBDHxJDtpmgFRzjVunG2EH0FF_k_F4f9C7RM_P3fcG9AjCVge1c565jjI yNtty0nQFciOWrON1w4Pax9ttCpfRWVQikEIvtE8lqpBKa8mCDxMrZdeLSQf o99Iok.ZwpH0YLoDHHePVmU982F4.BUTWFWqliGnG312Xduj4JlW3mtrysBa z2DUzwgFsBPH2jUUyyUyW_J5jIoscJCleQQjTM8tACuIxbMBpgLOQpqPyzr3 DhC5.emTIXQynwWnZiKwTEGMdaKwDiNtvf_knpvc9uE607Wm7rDGwtk_8KbA zyCMbZUvOi5PE2nyX7.PJvUeP X-Yahoo-SMTP: NQQt3c2swBAKSrExoA1eZuT7_w-- X-Rocket-Received: from [192.168.1.103] (n20087@24.254.184.40 with xymcookie [216.39.61.254]) by smtp205.mail.bf1.yahoo.com with SMTP; 20 May 2014 15:57:18 -0700 PDT Subject: Gear extension failure video References: From: Tom Content-Type: multipart/alternative; boundary=Apple-Mail-3F60356B-A92B-44F9-AC4B-CFDDBBFF448C X-Mailer: iPad Mail (11D201) In-Reply-To: X-Original-Message-Id: <73E93E97-590E-4DBF-BA35-44CEE44D6A5E@yahoo.com> X-Original-Date: Tue, 20 May 2014 18:57:16 -0400 X-Original-To: Lancair Mailing List Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-3F60356B-A92B-44F9-AC4B-CFDDBBFF448C Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable > Just to add to what Chris has presented, I experienced the same issue that= started this thread in the early days of proving out my gear during phase 1= testing. I had two instances of the gear locking up in the air. Funny eno= ugh it never happened while the aircraft was on jacks until I fiddled with t= he pressure switches to prove the point. I did have a few things confoundin= g the problem such as a reversed spool in the pump and one pressure switch w= ith hysteresis all over the map. In any case, the clincher was instrumentin= g the system with pressure gauges on both sides of the circuit as described b= y Chris. Things behaved exactly as demonstrated in the video. I knew my l= ow side pressure setting was off and the root cause but I had not gone into t= he detailed analysis as presented by Chris to figure out what was going on i= nside the pump. Having spent some time around high powered hydraulic servo v= alves and associated systems in my professional career I cannot find fault w= ith Chris's conclusions and am very grateful for his effort and insight Btw.. I did upgrade my pump to the higher flow rate which really speeds up t= he gear cycle. I also installed a quality three way dump valve which was no= t entirely necessary but it gives me piece of my mind that I can relieve pre= ssure under every circumstance but the biggest benefit was from removing the= crappy unit that was part of the kit. =20 In at least 400 gear cycles since dialing in the system I have had only one g= ear retract failure which was due to heat soaking in the florida sun which w= as easily resolved by a quick twist and reset of the dump valve Tom Lnc2=20 315 hrs= --Apple-Mail-3F60356B-A92B-44F9-AC4B-CFDDBBFF448C Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Just to add to what Chris has presented, I= experienced the same issue that started this thread in the early days of pr= oving out my gear during phase 1 testing.  I had two instances of the g= ear locking up in the air.  Funny enough it never happened while the ai= rcraft was on jacks until I fiddled with the pressure switches to prove the p= oint.  I did have a few things confounding the  problem such as a r= eversed spool in the pump and one pressure switch with hysteresis all over t= he map.  In any case, the clincher was instrumenting the system with pr= essure gauges on both sides of the circuit as described by Chris.  Thin= gs behaved exactly as demonstrated in the video.   I knew my low side p= ressure setting was off and the root cause but I had not gone into the detai= led analysis as presented by Chris to figure out what was going on inside th= e pump.  Having spent some time around high powered hydraulic servo val= ves and associated systems in my professional career I cannot find fault wit= h Chris's conclusions and am very grateful for his effort and insight=

Btw.. I did upgrade my pump to the higher flow rate which re= ally speeds up the gear cycle.  I also installed a quality three way du= mp valve which was not entirely necessary but it gives me piece of my mind t= hat I can relieve pressure under every circumstance but the biggest benefit w= as from removing the crappy unit that was part of the kit.  
=
In at least 400 gear cycles since dialing in the system I hav= e had only one gear retract failure which was due to heat soaking in the flo= rida sun which was easily resolved by a quick twist and reset of the dump va= lve

Tom

Lnc2 
315 hrs= --Apple-Mail-3F60356B-A92B-44F9-AC4B-CFDDBBFF448C--