X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 10 Feb 2012 10:26:19 -0500 Message-ID: X-Original-Return-Path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.123] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTP id 5389770 for lml@lancaironline.net; Thu, 09 Feb 2012 16:02:10 -0500 Received-SPF: none receiver=logan.com; client-ip=71.74.56.123; envelope-from=Wolfgang@MiCom.net X-Original-Return-Path: X-Authority-Analysis: v=2.0 cv=HeuWv148 c=1 sm=0 a=MHZY6FYWMEQOp7S43i2QIw==:17 a=sKbcXzeefecA:10 a=ttCsPuSJ-FAA:10 a=CjxXgO3LAAAA:8 a=Ia-xEzejAAAA:8 a=5FIZSGrRAAAA:8 a=rTjvlri0AAAA:8 a=ndVRne3UAAAA:8 a=9yAuKPzuWkB5SYdnBEEA:9 a=pTQKTzrDcjiTQWZqOWUA:7 a=wPNLvfGTeEIA:10 a=VQWZxD7wvt0A:10 a=nrXl3C1RZZ4A:10 a=rC2wZJ5BpNYA:10 a=EzXvWhQp4_cA:10 a=Dr9Wx-Q63l4A:10 a=Whv8HLVs5OMA:10 a=t0JpM0Q4tUj35nAIQakA:9 a=G6WgTnd5f89j5AnslZ8A:7 a=tXsnliwV7b4A:10 a=MHZY6FYWMEQOp7S43i2QIw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.218.201.50 Received: from [74.218.201.50] ([74.218.201.50:1941] helo=lobo) by hrndva-oedge04.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id DB/2C-01703-D24343F4; Thu, 09 Feb 2012 21:01:34 +0000 X-Original-Message-ID: <000d01cce76e$005dae20$6701a8c0@lobo> From: "Wolfgang" X-Original-To: Subject: Re: 320/360 Hydraulic Pressure Switch X-Original-Date: Thu, 9 Feb 2012 16:01:32 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000A_01CCE744.175599A0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_000A_01CCE744.175599A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable If it takes that much force to move the spindle against the O-rings then = those springs must be pretty darn strong. I find that dificult to = accept. Still, that port with the added spring, I believe it's a return port for = excess hydraulic fluid that can be used with a three port dump valve. . . . but why the spring if it's plugged anyway ? If the ultimate answer is to remove the "extra" springs, then let's = demonstrate that by testing a pump with the springs under pressure, = heat, AND simulated engine vibration. Short of that, this failure mode = remains a question. Wolfgang From: Chris Zavatson =20 Sender: =20 Subject: Re: [LML] Fw: [LML] Re: 320/360 Hydraulic Pressure = Switch=20 Date: Wed, 08 Feb 2012 08:05:15 -0500=20 To: lml@lancaironline.net=20 =20 Wolfgang, The ball and spring go in the port labeled "Cavity "E" = Back-Pressure". This is the pipe plug that sits in between the two = output ports. You might consider securing the dump valve with a secondary = locking feature. It too relies on friction alone to stay in position. = Seriously, given the force it takes to move the spool, if mine were not = staying put, I would want to know why. =20 From previous measurements: Using O-ring 013-70 requires 30 g's to move the spool. Using O-ring 013-90 requires 70 g's to move the spool.=20 The 013-90 is specified for pumps with back pressure circuits such = as we have. Chris Zavatson N91CZ 360std www.N91CZ.net =20 From: Wolfgang To: lml@lancaironline.net=20 Sent: Monday, February 6, 2012 9:24 AM Subject: [LML] Fw: [LML] Re: 320/360 Hydraulic Pressure Switch I see the centering springs but what about the added spring, = eyelet and ball ? Where does that fit into the schematic ? I still don't like the idea of friction being the only thing = keeping spindle at it's end point. Sure, removing the springs will help = but a positive system to pressure the spindle back into it's required = position automatically as needed still seems prudent. Wolfgang ----- Original Message -----=20 From: Chris Zavatson=20 To: lml@lancaironline.net=20 Sent: Sunday, February 05, 2012 8:34 AM Subject: Re: [LML] Re: 320/360 Hydraulic Pressure Switch Several folks have been asking privately about the spool centering = springs mentioned below. This link contains both schematics and photos = showing how to revert a new pump back to the original 320/360 = functionality. =20 http://www.n91cz.com/Hydraulics/Pump-Unlock.pdf Chris Zavatson N91CZ 360std www.N91CZ.net From: Chris Zavatson To: lml@lancaironline.net=20 Sent: Wednesday, February 1, 2012 12:46 PM Subject: [LML] Re: 320/360 Hydraulic Pressure Switch Lorn, Had the temperature been 90 or 100 degrees your pressure would = have been even higher. In some of my hydraulics videos, you will see = the 2,000 psi gauge pegged on occasion during thermal heating tests. http://www.n91cz.com/Hydraulics/Lancair_Hydraulics.htm Your predicament of having to crack a hydraulic line is exactly = what can happen if the spool centers after pump shut down. I find that = a completely unacceptable design. Imagine taking off into IMC and the = gear won't come up. I had the opportunity to test out a pump in this = configuration last summer. Just as you experienced, I was able to = reproduce a complete lock up. =20 http://www.n91cz.com/Hydraulics/NewPumpLockUp_0001.wmv - hi res http://www.n91cz.com/Hydraulics/NewPumpLockUp_0002.wmv - low res After discussions with Lancair and Parker, I reverted the = configuration back to the original 320/360 config and all is good now. = Only one side can ever be pressurized at a time. Unfortunately due to = employee turn-over, no one currently at Parker or Lancair knows why the = centering springs were added. After reviewing the 320/360 system both = agreed that a system lock up is possible using replacement pumps = currently sold (108AMS32-CZZ-3V-14-08-Y). Parker sent me parts to = revert three pumps back to the original configuration.=20 The TRVs in our pumps are the lowest available -fixed setting of = 2,500 psi. This may be too high to protect some of our components. I = have run them up to 2,000 psi. In flight, I have seen 1,800 psi, = descending from 18k into the southwest deserts. Chris Zavatson N91CZ 360std www.N91CZ.net From: Lorn H Olsen To: lml@lancaironline.net=20 Sent: Wednesday, February 1, 2012 6:33 AM Subject: [LML] Re: 320/360 Hydraulic Pressure Switch Again, My Oildyne internal pressure switch came (set by Oildyne) at 1,500 = PSI. How do I know? I parked my plane on the ramp at Newport News, Va in = the evening. The temperature was 40=B0F. 3 days later, when I was going = to take off. The temperature was 80=B0F. I looked at my pressure gauges. = Both the up and down were at 1,500 PSI. I had to crack a nut in a = hydraulic line to release the pressure. The gear would not go up or = down, at this pressure. The emergency dump valve would not release, at = this pressure. The pump would not run at all, at this pressure. Now, I have Wolfgang's high pressure adapter in the system. It = runs the pump whenever the pressure is high on both the up and the down = side. There is no speculation here. Just the facts, mam. -- Lorn H. 'Feathers' Olsen, MAA, ASMEL, ASES, Comm, Inst DynaComm, Corp., 248-345-0500, mailto:lorn@dynacomm.us LNC2, FB90/92, O-320-D1F, 1,800 hrs, N31161, Y47, SE Michigan =20 ------=_NextPart_000_000A_01CCE744.175599A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
If it takes that much force to move the spindle against the O-rings = then=20 those springs must be pretty darn strong. I find that dificult to = accept.
 
Still, that port with the added spring, I believe it's a return = port for=20 excess hydraulic fluid that can be used with a three port dump = valve.
. . . but why the spring if it's plugged anyway ?
 
If the ultimate answer is to remove the "extra" springs, then let's = demonstrate that by testing a pump with the springs under pressure, = heat, AND=20 simulated engine vibration. Short of that, this failure mode remains a=20 question.
 
Wolfgang


 
lml@lancaironline.net
From: Chris Zavatson=20 <chris_zavatson@yahoo.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Fw: [LML] Re: 320/360 = Hydraulic=20 Pressure Switch
Date: Wed, 08 Feb 2012 08:05:15 = -0500
To:
Wolfgang,
The ball and spring go in the port labeled "Cavity "E"=20 Back-Pressure".  This is the pipe plug that sits in between = the two=20 output ports.
 
You might consider = securing=20 the dump valve with a secondary locking feature.  It too = relies on=20 friction alone to stay in position.  Seriously, given the = force it=20 takes to move the spool, if mine were not staying put, I = would want=20 to know why. 
 
From previous measurements:
Using O-ring 013-70 requires 30 g's to move the = spool.
Using O-ring 013-90 requires 70 g's to move the spool. =
The 013-90 is specified for pumps with back pressure = circuits=20 such as we have.
 
Chris=20 Zavatson
N91CZ
360std
www.N91CZ.net
 
From: = Wolfgang=20 <Wolfgang@MiCom.net>
To:=20 lml@lancaironline.net
Sent: Monday, = February 6,=20 2012 9:24 AM
Subject: [LML] Fw: [LML] Re: = 320/360=20 Hydraulic Pressure Switch

I see the centering springs but what about the added spring, = eyelet=20 and ball ? Where does that fit into the schematic ?
 
I still don't like the idea of friction being the only thing = keeping=20 spindle at it's end point. Sure, removing the springs will help = but a=20 positive system to pressure the spindle back into it's required = position=20 automatically as needed still seems prudent.
 
Wolfgang
 
----- Original Message -----=20
Sent: Sunday, February 05, 2012 8:34 AM
Subject: Re: [LML] Re: 320/360 Hydraulic Pressure=20 Switch

Several folks have been asking privately about the spool = centering=20 springs mentioned below.  This link contains both schematics = and=20 photos showing how to revert a new pump back to the = original 320/360 functionality. 
http://www.n91cz.com/Hydraulics/Pump-Unlock.pdf
 
Chris Zavatson
N91CZ
360std


From: Chris = Zavatson=20 <chris_zavatson@yahoo.com>
To:=20 lml@lancaironline.net
Sent: Wednesday, = February 1,=20 2012 12:46 PM
Subject: [LML] Re: 320/360 = Hydraulic=20 Pressure Switch

Lorn,
Had the temperature been 90 or 100 degrees your pressure = would have=20 been even higher.  In some of my hydraulics videos, you = will see=20 the 2,000 psi gauge pegged on occasion during thermal heating = tests.
 
http://www.n91cz.com/Hydraulics/Lancair_Hydraulics.htm
 
Your predicament of having to crack a hydraulic line is = exactly=20 what can happen if the spool centers after pump shut down.  I = find=20 that a completely unacceptable design.  Imagine taking off = into IMC=20 and the gear won't come up.  I had the opportunity to test = out a pump=20 in this configuration last summer.  Just as you experienced, = I was=20 able to reproduce a complete lock up. 
http://www.n91cz.com/Hydraulics/NewPumpLockUp_0001.wmv - = hi=20 res
http://www.n91cz.com/Hydraulics/NewPumpLockUp_0002.wmv - = low=20 res
 
After discussions with Lancair and Parker, I reverted = the=20 configuration back to the original=20 320/360 config and all is good now.  Only one side can ever = be=20 pressurized at a time.  Unfortunately due to employee = turn-over, no=20 one currently at Parker or Lancair knows why the centering springs = were=20 added.  After reviewing the 320/360 system both agreed that a = system=20 lock up is possible using replacement pumps currently sold=20 (108AMS32-CZZ-3V-14-08-Y).  Parker sent me parts to revert = three=20 pumps back to the original configuration. 
 
The TRVs in our pumps are the lowest available -fixed setting = of=20 2,500 psi.  This may be too high to protect some of = our=20 components.  I have run them up to 2,000 = psi.  In=20 flight, I have seen 1,800 psi, descending from 18k into the = southwest=20 deserts.
 
Chris Zavatson
N91CZ
360std
 
 

From: Lorn H=20 Olsen <lorn@dynacomm.us>
To:=20 lml@lancaironline.net
Sent: Wednesday, = February 1,=20 2012 6:33 AM
Subject: [LML] Re: 320/360 = Hydraulic=20 Pressure Switch

Again,

My Oildyne = internal=20 pressure switch came (set by Oildyne) at 1,500 PSI. How do I know? = I=20 parked my plane on the ramp at Newport News, Va in the evening. = The=20 temperature was 40=B0F. 3 days later, when I was going to take = off. The=20 temperature was 80=B0F. I looked at my pressure gauges. Both the = up and down=20 were at 1,500 PSI. I had to crack a nut in a hydraulic line to = release the=20 pressure. The gear would not go up or down, at this pressure. The=20 emergency dump valve would not release, at this pressure. The pump = would=20 not run at all, at this pressure.

Now, I have Wolfgang's = high=20 pressure adapter in the system. It runs the pump whenever the = pressure is=20 high on both the up and the down side.

There is no = speculation=20 here. Just the facts, mam.


--
Lorn H. 'Feathers' = Olsen, MAA,=20 ASMEL, ASES, Comm, Inst
DynaComm, Corp., 248-345-0500, = mailto:lorn@dynacomm.us
LNC2, = FB90/92,=20 O-320-D1F, 1,800 hrs, N31161, Y47, SE=20 = Michigan
<= /DIV>
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