X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 13 Feb 2012 09:23:38 -0500 Message-ID: X-Original-Return-Path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTP id 5393193 for lml@lancaironline.net; Sun, 12 Feb 2012 12:30:46 -0500 Received-SPF: none receiver=logan.com; client-ip=71.74.56.125; envelope-from=Wolfgang@MiCom.net X-Original-Return-Path: X-Authority-Analysis: v=2.0 cv=MaXuSuDf c=1 sm=0 a=MHZY6FYWMEQOp7S43i2QIw==:17 a=hKNyXSRXzacA:10 a=ttCsPuSJ-FAA:10 a=Ia-xEzejAAAA:8 a=5FIZSGrRAAAA:8 a=rTjvlri0AAAA:8 a=CjxXgO3LAAAA:8 a=ndVRne3UAAAA:8 a=SA18rOEZ0840qMBxmMkA:9 a=FuReOYmDr0f__RfNsPIA:7 a=wPNLvfGTeEIA:10 a=VQWZxD7wvt0A:10 a=nrXl3C1RZZ4A:10 a=wR8WdYEwGqoA:10 a=EzXvWhQp4_cA:10 a=Dr9Wx-Q63l4A:10 a=rC2wZJ5BpNYA:10 a=Whv8HLVs5OMA:10 a=1rAAZHoqQ59MaAbFV2QA:9 a=ShSChu4AfwifDdsG2c8A:7 a=tXsnliwV7b4A:10 a=MHZY6FYWMEQOp7S43i2QIw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.218.201.50 Received: from [74.218.201.50] ([74.218.201.50:1072] helo=lobo) by hrndva-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 5F/96-05484-227F73F4; Sun, 12 Feb 2012 17:30:10 +0000 X-Original-Message-ID: <003d01cce9ab$f522cdc0$6701a8c0@lobo> From: "Wolfgang" X-Original-To: Subject: Fw: [LML] Re: 320/360 Hydraulic Pressure Switch X-Original-Date: Sun, 12 Feb 2012 12:30:04 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003A_01CCE982.0C1AB940" 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_003A_01CCE982.0C1AB940 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Interesting . . . indeed. So, since there seems to be no published standard on the required pump = details from Oildyne and more importantly from Lancair, one is left to = chance to have the right components in their pump to assure proper and = reliable operation as needed for a Lancair. The only way to validate a = pump is to take it apart and verify the spring situation and durometer = of the O-rings after the fact.=20 Shameless plug . . . or install my add-on safety module which doesn't = care about springs or durometer but simply makes the pump operate like = it's supposed to. Wolfgang ----- Original Message -----=20 From: Chris Zavatson=20 To: lml@lancaironline.net=20 Sent: Saturday, February 11, 2012 8:50 PM Subject: Re: [LML] Re: 320/360 Hydraulic Pressure Switch Indeed, the springs are very strong. You can sort of see that in the = photos. The wire diameter is quite hefty. Using a brand new 013-70 O-ring (for applications where the spool does = not need to stay put), the spring generates 4x the force required to = move the spool. If your spool is not staying in position: 1. Check for and, if found, remove return springs (for pumps purchased = new or repaired by Oildyne since ~2003) 2. Make sure the spool has an O-ring (two for symmetric spools) 3. Make sure the spool has the 90 durometer O-ring=20 =20 Chris Zavatson N91CZ 360std www.N91CZ.net From: Wolfgang To: lml@lancaironline.net=20 Sent: Friday, February 10, 2012 7:26 AM Subject: [LML] Re: 320/360 Hydraulic Pressure Switch 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 =20 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, InstDynaComm, Corp., 248-345-0500, = mailto:lorn@dynacomm.usLNC2, FB90/92, O-320-D1F, 1,800 hrs, N31161, Y47, = SE Michigan=20 ------=_NextPart_000_003A_01CCE982.0C1AB940 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Interesting . . . indeed.
 
So, since there seems to be no = published standard=20 on the required pump details from Oildyne and more importantly from = Lancair, one=20 is left to chance to have the right components in their pump to assure = proper=20 and reliable operation as needed for a Lancair. The only way to validate = a pump=20 is to take it apart and verify the spring situation and durometer of the = O-rings=20 after the fact.
 
Shameless plug . . . or install my = add-on safety=20 module which doesn't care about springs or durometer but simply makes = the pump=20 operate like it's supposed to.
 
Wolfgang
 
 
----- Original Message -----=20
From: Chris=20 Zavatson
Sent: Saturday, February 11, 2012 8:50 PM
Subject: Re: [LML] Re: 320/360 Hydraulic Pressure = Switch

Indeed, the = springs are very strong.  You can sort of = see that in=20 the photos.  The wire diameter is quite hefty.
Using a = brand=20 new 013-70 O-ring (for applications where the spool does not need = to stay=20 put), the spring generates 4x the force required to move the = spool.
 
If your spool is = not staying=20 in position:
1. Check = for and, if=20 found, remove return springs (for pumps purchased new or repaired by = Oildyne=20 since ~2003)
2. Make sure the = spool has an=20 O-ring (two for symmetric spools)
3. Make sure = the spool=20 has the 90 durometer O-ring 
  
Chris Zavatson
N91CZ
360std
 
From: Wolfgang=20 <Wolfgang@MiCom.net>
To:=20 lml@lancaironline.net
Sent:=20 Friday, February 10, 2012 7:26 AM
Subject: [LML] Re: 320/360 = Hydraulic=20 Pressure Switch
If it takes that much force to move the = spindle against=20 the O-rings then those springs must be pretty darn strong. I find that = dificult=20 to accept.
 
Still, that port with the added spring, I = believe it's=20 a return port for excess hydraulic fluid that can be used with a three = port dump=20 valve.
. . . but why the spring if it's plugged = anyway ?
 
If the ultimate answer is to remove the = "extra"=20 springs, then let's demonstrate that by testing a pump with the springs = under=20 pressure, heat, AND simulated engine vibration. Short of that, this = failure mode=20 remains a question.
 
Wolfgang

 
lml@lancaironline.net=
From: Chris=20 Zavatson <chris_zavatson@yahoo.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Fw: [LML] Re: = 320/360=20 Hydraulic Pressure Switch
Date: Wed, 08 Feb=20 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=20 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=20 pressure circuits such as we have.
 
Chris = Zavatson
N91CZ
360std
 
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=20 added spring, eyelet and ball ? Where does that fit into the = schematic=20 ?
 
I still don't like the idea of friction = being the=20 only thing keeping spindle at it's end point. Sure, removing the = springs=20 will help but a positive system to pressure the spindle back into = it's=20 required position automatically as needed still seems = prudent.
 
Wolfgang
 
----- Original Message -----=20
Sent: = Sunday, February=20 05, 2012 8:34 AM
Subject: = Re: [LML] Re:=20 320/360 Hydraulic Pressure 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=20 pressure would have been even higher.  In some of my = hydraulics=20 videos, you will see the 2,000 psi gauge pegged on occasion = during=20 thermal heating tests.
 
http://www.n91cz.com/Hydraulics/Lancair_Hydraulics.htm
 
Your predicament of having to = crack a=20 hydraulic line is exactly what can happen if the spool centers = after pump=20 shut down.  I find that a completely unacceptable = design. =20 Imagine taking off into IMC and the gear won't come up.  I = had the=20 opportunity to test out a pump in this configuration last = summer. =20 Just as you experienced, I was able to reproduce a complete lock = up. =20
http://www.n91cz.com/Hydraulics/NewPumpLockUp_0001.wmv - = hi=20 res
http://www.n91cz.com/Hydraulics/NewPumpLockUp_0002.wmv -=20 low res
 
After = discussions with=20 Lancair and Parker, I reverted the configuration back to the original 320/360 config and all = is good=20 now.  Only one side can ever be pressurized at a time. =20 Unfortunately due to employee turn-over, no one currently at = Parker or=20 Lancair knows why the centering springs were added.  After = reviewing=20 the 320/360 system both agreed that a system lock up is possible = using=20 replacement pumps currently sold (108AMS32-CZZ-3V-14-08-Y).  = Parker=20 sent me parts to revert three pumps back to the original=20 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,=20 MAA, ASMEL, ASES, Comm, InstDynaComm, Corp., 248-345-0500, = mailto:lorn@dynacomm.usLNC2, = FB90/92,=20 O-320-D1F, 1,800 hrs, N31161, Y47, SE=20 = Michigan
=
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