Return-Path: Sender: "Marvin Kaye" To: lml@lancaironline.net Date: Thu, 03 Mar 2005 17:07:25 -0500 Message-ID: X-Original-Return-Path: Received: from imo-d21.mx.aol.com ([205.188.144.207] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 769101 for lml@lancaironline.net; Thu, 03 Mar 2005 17:01:27 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.144.207; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-d21.mx.aol.com (mail_out_v37_r3.8.) id q.9e.21705b77 (16633) for ; Thu, 3 Mar 2005 17:00:35 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <9e.21705b77.2f58e303@aol.com> X-Original-Date: Thu, 3 Mar 2005 17:00:35 EST Subject: Re: [LML] Re: 360 Hydraulics Problem X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1109887235" X-Mailer: 9.0 Security Edition for Windows sub 5000 -------------------------------1109887235 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 3/3/2005 3:04:43 P.M. Central Standard Time, Michael.S.Reinath@nasa.gov writes: Remember, more fluid volume has to return to the pump, and the tank, than is being pumped out to the cylinder, during a retraction. This difference occurs because the cylinder shafts displace fluid on the high side only........................ Mike, Gerard, et al Very interesting point. Let's see, if the piston is 1 5/16" and the shaft is 5/16", the retract force has to be about 6% higher to move the same weight since the shaft reduces the area acted on by the hydraulic fluid pressure. More interesting, when I next go to the airport, I will measure the door actuator piston and shaft and see why it takes so much more pressure to snug everything up - especially the doors that have now almost fully compressed the springs on the actuators by then. My spool is correctly oriented yet sometimes (usually in the winter), there is a hiccup after no more than a second or two to finally tuck everything away after the takeoff retract. Another thing I have noticed is the wear on the legs (slight dent) and door sequence valve's actuating screw heads (slight flattening) after about 700 in flight retracts and, I am sure, another 100-200 retracts whilst on jacks. One should consider that those valves may not be completely opening and may need readjustment to achieve full flow of fluid. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Fair and Balanced Opinions at No Charge! Metaphysical Monologues taken at your own Risk. -------------------------------1109887235 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 3/3/2005 3:04:43 P.M. Central Standard Time,=20 Michael.S.Reinath@nasa.gov writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>Remember, more fluid volume has to return to the pump, and the ta= nk,=20 than is being pumped out to the cylinder, during a retraction. This differ= ence=20 occurs because the cylinder shafts displace fluid on the high side=20 only........................
Mike, Gerard, et al
 
Very interesting point.  Let's see, if the piston is 1 5/16" and t= he=20 shaft is 5/16", the retract force has to be about 6% higher to move the same= =20 weight since the shaft reduces the area acted on by the hydraulic fluid=20 pressure.
 
More interesting, when I next go to the airport, I will measure the doo= r=20 actuator piston and shaft and see why it takes so much more pressure to snug= =20 everything up - especially the doors that have now almost fully compressed t= he=20 springs on the actuators by then.
 
My spool is correctly oriented yet sometimes (usually in the winter), t= here=20 is a hiccup after no more than a second or two to finally tuck everything aw= ay=20 after the takeoff retract.
 
Another thing I have noticed is the wear on the legs (slight dent) = ;and=20 door sequence valve's actuating screw heads (slight flattening) after a= bout=20 700 in flight retracts and, I am sure, another 100-200 retracts whilst on=20 jacks.  One should consider that those valves may not be completely ope= ning=20 and may need readjustment to achieve full flow of fluid.=20
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)

Fai= r=20 and Balanced Opinions at No Charge!
Metaphysical Monologues taken at your= own=20 Risk.

-------------------------------1109887235--