X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 26 Nov 2006 21:44:05 -0500 Message-ID: X-Original-Return-Path: Received: from mta-out-1.udlp.com ([207.109.1.8] verified) by logan.com (CommuniGate Pro SMTP 5.1.2) with ESMTP id 1604322 for lml@lancaironline.net; Sun, 26 Nov 2006 13:47:10 -0500 Received-SPF: none receiver=logan.com; client-ip=207.109.1.8; envelope-from=Christopher.Zavatson@baesystems.com Received: from mnexch01.MSGDOMAIN.MPLS.UDLP.COM ([10.66.62.99]) by mta-out-1.udlp.com (8.13.6/8.13.6) with ESMTP id kAQHr46h014191 for ; Sun, 26 Nov 2006 11:53:04 -0600 Received: from smtp.udlp.com ([10.66.69.54] RDNS failed) by mnexch01.MSGDOMAIN.MPLS.UDLP.COM with Microsoft SMTPSVC(6.0.3790.211); Sun, 26 Nov 2006 12:39:27 -0600 Received: from DM-MN-06-MTA by smtp.udlp.com with Novell_GroupWise; Sun, 26 Nov 2006 12:46:31 -0600 X-Original-Message-Id: X-Mailer: Novell GroupWise Internet Agent 6.5.6 X-Original-Date: Sun, 26 Nov 2006 12:46:18 -0600 From: "Christopher Zavatson" X-Original-To: Subject: [LML] Re: Electrical /Hydraulic system questionslancair235/320 Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="=__Part4E6A6FEA.0__=" X-OriginalArrivalTime: 26 Nov 2006 18:39:27.0634 (UTC) FILETIME=[33D89720:01C7118A] --=__Part4E6A6FEA.0__= Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Bob, One of the tests I recorded this weekend was for the scenario of pushing the gear up by hand with the spool valve in the down position. It is becoming clear through this hydraulics thread that there exit some internal differences between the early pumps and current models. In this video, I extend a single cylinder on the test bench. The test bench is set up just like the aircraft system. After "extending the gear" I turn off power to the pump and open the dump valve. Next I try to retract the cylinder by hand. You can see the pressure build in both sides of the cylinder. Since the spool valve is still in the "down" position, the back pressure circuit is not active. Attempting to push the rod volume into the fluid system produces the pressure seen on the gauges. Once I bump the pump in the up direction and the spool valve slide over to the "up" posistion, I can push the rod all the way in without pressure build up. Again, this behavior only applies to the most recent configuration. Here is a link. http://www.N91CZ.com/Hydraulics/Push_Gear_Up_Hydr_Lock.WMV Chris Chris Zavatson N91CZ 360std. www.N91CZ.com --=__Part4E6A6FEA.0__= Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Description: HTML
Bob,
One of the tests I recorded this weekend was for the scenario of = pushing the gear up by hand with the spool valve in the down position. = ; It is becoming clear through this hydraulics thread that there exit some = internal differences between the early pumps and current models.
 
In this video, I extend a single cylinder on the test bench.  = The test bench is set up just like the aircraft system.  After = "extending the gear" I turn off power to the pump and open the dump = valve.  Next I try to retract the cylinder by hand.  You can see = the pressure build in both sides of the cylinder.  Since the spool = valve is still in the "down" position, the back pressure circuit is not = active.  Attempting to push the rod volume into the fluid system = produces the pressure seen on the gauges.  Once I bump the pump in = the up direction and the spool valve slide over to the "up" posistion, I = can push the rod all the way in without pressure build up.
Again, this behavior only applies to the most recent configuration.
 
Here is a link.
Chris
 
 
 
 
Chris Zavatson
N91CZ
360std.
 
 
 
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