X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 15 Oct 2008 01:40:30 -0400 Message-ID: X-Original-Return-Path: Received: from bay0-omc1-s28.bay0.hotmail.com ([65.54.246.100] verified) by logan.com (CommuniGate Pro SMTP 5.2.8) with ESMTP id 3211410 for lml@lancaironline.net; Mon, 13 Oct 2008 19:25:56 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.54.246.100; envelope-from=gt_phantom@hotmail.com Received: from hotmail.com ([10.12.232.162]) by bay0-omc1-s28.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.3959); Mon, 13 Oct 2008 16:25:20 -0700 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Mon, 13 Oct 2008 16:25:20 -0700 X-Original-Message-ID: Received: from 72.145.251.121 by COL0-DAV24.phx.gbl with DAV; Mon, 13 Oct 2008 23:25:17 +0000 X-Originating-IP: [72.145.251.121] X-Originating-Email: [gt_phantom@hotmail.com] X-Sender: gt_phantom@hotmail.com From: "GT-Phantom" X-Original-To: Subject: Hydraulic Woes X-Original-Date: Mon, 13 Oct 2008 19:25:20 -0400 X-Original-Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0014_01C92D69.6E46A7B0" X-Mailer: Microsoft Office Outlook 11 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Thread-Index: AcktivUamdgUvQCWTWm4Njb6XkZ2Iw== X-OriginalArrivalTime: 13 Oct 2008 23:25:20.0083 (UTC) FILETIME=[F54ADA30:01C92D8A] X-Original-Return-Path: gt_phantom@hotmail.com This is a multi-part message in MIME format. ------=_NextPart_000_0014_01C92D69.6E46A7B0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit After over a year rennovating, I am hopefully in sight of flying again. Need some help from wiser heads on my gear system. Situation: - Lancair 320 small tail, 18 years old. - New hydraulic pack factor adjusted to max pressures of 1300psi up / 800psi down - New style factory preset pressure switches 1100 up / 550 down - Many hoses replaced with fresh hosing, most fluid drained from system prior to testing - Tested 20 cycles hoping to purge all air - don't think that worked The good: - Everything swings easily by hand with the pressure dump valve in the dump position. - Running the pump with pressure switches bypassed results in 6-8 second activation time until pump labors, with sequence valves operating as expected and doors closing flush - There are no signs of leaks The bad: - With the pressure switches installed in the circuit, the pump cycles MANY times to reach full retraction and even a few times to reach full extension (rather than a nice continuous run to shut-off) - Once retracted or extended, switch cycles VERY quickly (I think this means bypass /check valves are set too low or air compressibility in line) - Once retracted and pump manually turned off, pressure slowly bleeds (same as above, I suspect bypass / check valves set too low or air compressibility in line) - System just seems like there must be a LOT of air in it which rapidly compresses then slowly pushes the gear in the intended direction I can verify the check valve pressures with a mechanical pressure gage, ran out of time but am comfortable that I can resolve check / bypass valve issues. Questions: - Can anyone verify (or refute) my theory about the rapid switch cycling at full extension / retraction? If not check valves, solution? - Does anyone know of a good way to completely purge the system of air? - Has anyone determined conclusively that the "recommended" pressures of 1100/550 simply AREN'T enough? - How high is safe for the system if I go up on either of the pressure switches? My prior plane was a 235 with a virtually identical system (I did not build either one) and, although it might cycle once or twice at the end of the retract cycle would then immediately be quiet (although on a very long flight it might "burp" once or twice in the up direction to maintain up pressure). All help appreciated! Cheers, Bill Reister ------=_NextPart_000_0014_01C92D69.6E46A7B0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
After = over a year=20 rennovating, I am hopefully in sight of flying again.  =
 
Need = some help from=20 wiser heads on my gear system.  Situation:
 
- = Lancair 320 small=20 tail, 18 years old.
-=20 New=20 hydraulic pack factor adjusted to max pressures of 1300psi up / 800psi=20 down
-=20 New style=20 factory preset pressure switches 1100 up / 550 down
- Many = hoses=20 replaced with fresh hosing, most fluid drained from system prior to=20 testing
- = Tested 20 cycles=20 hoping to purge all air - don't think that worked
 
The = good: =20
- = Everything swings=20 easily by hand with the pressure dump valve in the dump position.=20
- = Running the pump=20 with pressure switches bypassed results in 6-8 second activation time = until pump=20 labors, with sequence valves operating as expected and doors closing=20 flush
- = There are no signs=20 of leaks
 
The=20 bad:
- With = the pressure=20 switches installed in the circuit, the pump cycles MANY times to reach = full=20 retraction and even a few times to reach full extension (rather than a = nice=20 continuous run to shut-off)
- Once = retracted or=20 extended, switch cycles VERY quickly (I think this means bypass /check = valves=20 are set too low or air compressibility in line)
- Once = retracted and=20 pump manually turned off, pressure slowly bleeds (same as above, I = suspect=20 bypass / check valves set too low or air compressibility in=20 line)
- = System just seems=20 like there must be a LOT of air in it which rapidly compresses then = slowly=20 pushes the gear in the intended direction
 
I can = verify the=20 check valve pressures with a mechanical pressure gage, ran out of time = but am=20 comfortable that I can resolve check / bypass valve = issues.
 
Questions:
- Can = anyone verify=20 (or refute) my theory about the rapid switch cycling at full extension / = retraction?  If not check valves, solution?
- Does = anyone know=20 of a good way to completely purge the system of air?
- Has = anyone=20 determined conclusively that the "recommended" pressures of 1100/550 = simply=20 AREN'T enough? 
- How = high is safe=20 for the system if I go up on either of the pressure=20 switches?
 
My = prior plane was a=20 235 with a virtually identical system (I did not build either one) and, = although=20 it might cycle once or twice at the end of the retract cycle would then=20 immediately be quiet (although on a very long flight it might "burp" = once or=20 twice in the up direction to maintain up pressure).  =
 
All = help=20 appreciated!
 
Cheers,
 
Bill=20 Reister
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