X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 04 Oct 2009 22:28:15 -0400 Message-ID: X-Original-Return-Path: Received: from web36901.mail.mud.yahoo.com ([209.191.85.69] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with SMTP id 3874205 for lml@lancaironline.net; Sun, 04 Oct 2009 19:38:18 -0400 Received-SPF: none receiver=logan.com; client-ip=209.191.85.69; envelope-from=chris_zavatson@yahoo.com Received: (qmail 8022 invoked by uid 60001); 4 Oct 2009 23:37:42 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:Cc:MIME-Version:Content-Type; b=mQyn5tz36AQZrWmioqk2ptJACg5pdPWq2BufNuMq69olJzEExfKmx7Z53eVUavHFPaGID64PWKpz+1fFBOBKk0wcEE+Woyv7f8ozY8h2QnJP/B61XnWzveJyL7WYrb2UzvNcfrBg1Idt3DCjFNX55mBJgnWuwnGubI6EHPg5//c=; X-Original-Message-ID: <132395.7580.qm@web36901.mail.mud.yahoo.com> X-YMail-OSG: dyNZmI4VM1kveYmP1E4wzol1FA4D9Rw_9J3WWSAgZFhog_0QGZ163ErJX6hSCD4LAw72IF86ynnmoOsHpPlANpIQvluxU18CSp.UHzgh2Mj3RuExAsJovF7a8MeAC_baF1PMN7pU7UA_nv7pUVKZsDuKLl9C5qPQCoZrjrd_t17PKqYoVyl1dDGYhJ92BQuDitfCDnseO.IPeK3cCU7V3CiCCHTgIb3_PyHA_pA8Fyh7NoY2jYpx0cwVNBXcMTVv9pfn6KFLvFcfxMBwRmIgy2IGalejQA9CbzgoFOzblOtdV0S_MG3XxfWk5S9HQHzNkgd_iMJ2ikWbiiNem.WkFETxXu.w.A-- Received: from [76.246.54.197] by web36901.mail.mud.yahoo.com via HTTP; Sun, 04 Oct 2009 16:37:41 PDT X-Mailer: YahooMailRC/182.10 YahooMailWebService/0.7.347.3 X-Original-Date: Sun, 4 Oct 2009 16:37:41 -0700 (PDT) From: Chris Zavatson Subject: Re: Lancair 320/360 hydraulic system questions and fixes X-Original-To: Wolfgang , Lorn Olsen , Lancair Mailing List X-Original-Cc: Christopher.Zavatson@baesystems.com, randystuart@hotmail.com, jmack102ea@gmail.com, JohnM@Lancair.com MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1518324725-1254699461=:7580" --0-1518324725-1254699461=:7580 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable "Problem #2 is that=A0vibration and pump internal leakage can move the spoo= l valve off it's position of all to one side or the other while the pump is= not running."=0A=0ASo the question still remains:=A0=A0Why do some spools = return to center=A0while other do not?=A0 All are subject to vibration.=A0 = My preference would be to identify the root cause and then decide if=A0it c= an or should=A0be addressed directly.=A0 It may be as simple as switching= =A0out a 20 cent O-ring on the spool.=A0 =0A=0A=0AChris Zavatson=0AN91CZ=0A= 360std=0Awww.N91CZ.com=0A=0A=0A=0A=0A________________________________=0AFro= m: Wolfgang =0ATo: Lorn Olsen =0ACc: = Christopher.Zavatson@baesystems.com; chris_zavatson@yahoo.com; randystuart@= hotmail.com; jmack102ea@gmail.com; JohnM@Lancair.com=0ASent: Fri, October 2= , 2009 6:28:25 PM=0ASubject: Lancair 320/360 hydraulic system questions and= fixes=0A=0A=0ALancair 320/360 hydraulic system questions and fixes=0AThere= have been instances of gear operation failure in the Lancer 320/360. I hav= e looked into this, spoken with Lorn Olsen-LNC2 owner, Brian Anderson-produ= ct manager=A0at OilDyne for the 108 pump, =A0Ross-320/360 specialist at Lan= cair, Christopher Zavatson-Lancair owner, Randy Stuart-Lancair owner and be= lieve I have the answers.=0A=A0=0AGear operation failure is usually due to = both HI/UP and LO/DN hydraulic pressures being above their respective press= ure switch settings preventing operation of the pump.=A0This happens becaus= e hydraulic fluid gets trapped in the lines and with a temperature rise, pr= essures exceed normal conditions.=0A=A0=0AThe pump used is an OilDyne=A0108= series with the "LB" circuit. http://www.parker.com/literature/Literature%= 20Files/euro_cylinder/v4/108_1301-uk.pdf=0AEarlier models were 108AM/19-CLB= 3VT-11-08, Lancair # 637715 and later models are 108AMS32-CZZ3V-14-08 Lanca= ir # 642666. The pump has check valves that operate with a 1:5 pressure rat= io. The ZZ in the newer pump is still=A0an LB circuit but with a slightly m= odified back pressure circuit. Looking at the pressure port side of the pum= p housing, the left port is labeled "U" and had the higher pressure output.= The right hand one is labeled "D" and has the lower pressure output. The b= ack pressure circuit is powered by pressure from the=A0"D" port connected t= o the rod side of the cylinders as shown on page 9 of the product literatur= e link above.=0A=A0=0AThis is problem # 1. This is backwards from the way t= he 320/360 needs it ! The Lancair 320/360=A0requires "U" pressure on the ro= d side of the cylinders to raise the gear using the higher pressure. For th= e back pressure valve to operate properly, the spool valve needs to be flip= ped around. This is why there have been reports of the spool being in backw= ards.=0A=A0=0AWith this corrected, everything works and all is right with t= he world.=0A=0A________________________________=0A=0AYou can check your own= system. You will need pressure gages in the HI and LO side to do this.=A0= =A0=0A=0APut the plane up on jacks.=0A=A0=0APower the gear up. =0AWith the = dump valve, induce a leak from HI side to LO side. =0ANote the pressure on = the LO side stays at zero.=0A=A0=0APower the gear down.=0AWith the dump val= ve, induce a leak from HI side to LO side.=0ANote the pressure on the HI si= de rises a bit and then goes back to zero.=0A- - - This is because the pres= sure has to leak back past the pump gears before it gets to the pressure re= lief valve.=0A=A0=0AThis is expected operation when the spool valve is in p= roperly and stays where it was last pressured.=0A=0A_______________________= _________=0A=0AMost of the time things work all right but there continue to= be reports of gear actuation failure.=0A=A0=0AProblem #2 is that=A0vibrati= on and pump internal leakage can move the spool valve off it's position of = all to one side or the other while the pump is not running. When this happe= ns, the check valves close and fluid is trapped in both the HI and LO sides= of the system. Temperature increase, cylinder=A0leakage and dump valve lea= kage can all=A0cause both sides to exceed pressure switch settings. (If the= re is leakage, the pump runs and can building pressure in both sides) The t= hermostatic relief valve settings=A0in the pump will prevent line pressures= from exceeding about 1500 psi.=0A=A0=0A=A0=0ASo, the fix is to prevent the= non-action side pressure from increasing above=A0it's pressure switch sett= ing due to heat soak or leakage and=A0bring it down if it does.=0A=A0=0AThi= s can be accomplished in two ways.=0A=0A________________________________=0A= =0A1 ) Hydraulic only =3D =3D =3D Add an accumulator to each HI and LO side= to absorb the temperature induced volume/pressure increase.=0A=A0=0AI init= ially thought=A05 cu.in. units (Parker # AD007B25T9A1) with a precharge of = about 100-200 psi would work even though they were larger than needed.=0A= =A0=0AUpon further examination, I considered a length of flexible (expandab= le) hose added to the system since that would be much easier to install. I = just needed to figure out the=A0required length. After=A0rounding up expans= ion numbers from AeroQuip on their 303-5 and 303-8 hose and other details;= =0A=A0=0A303-5 ID=3D1/4"=0A303-5 hose expansion=A0=3D 0.094cc / in at 1000 = psi=0A303-5 hose expansion=A0=3D 0.123cc / in at 2000 psi=0A303-5 hose expa= nsion=A0=3D 0.149cc / in at 3000 psi=0A=0A303-8 ID =3D 13/32"303-8 hose exp= ansion=A0=3D 0.100cc / in at 600 psi=0A303-8 hose expansion=A0=3D 0.137cc /= in at 1250 psi=0A303-8 hose expansion=A0=3D 0.171cc / in at 2000 psi=0A=A0= =0AHydraulic fluid volume in the LNC2 is about 27 cu in=A0;=A0=A06.4 cu in = in the lines,=A0;20.6 cu in the actuators=A0with door actuators=0AHydraulic= fluid thermal expansion coefficient=A0=3D .0005 / deg.F=0AAluminum thermal= expansion coefficient=A0=3D .0000123 / deg.F (negligible for this purpose)= =0AModulus of elasticity of hydraulic fluid=A0=3D 250,000 (compression unde= r pressure -=A0psi per percent=A0reduction in volume - negligible for this = purpose)=0A=0AI calculated that about 8ft of 303-5 with AN4=A0fittings woul= d provide the desired volume expansion from heat soak. =0A=A0=0AFluid in th= e non-action side of the system=A0=3D 3.2 cu in.=0A8ft of 303-5 line=A0=3D = 4.71 cu in=0AFluid in the non-action side of the system with added line=A0= =3D 7.9 cu in (ignoring volume of removed line segment)=0AExtrapolated volu= me increase in the added line at 300 psi=A0=3D 0.065cc / in=0AVolume increa= se =3D 0.065=A0/ 2.54^3 x 96 =3D 0.381 cu in=0ADelta T allowance =3D 0.381 = / (7.9 x 0.0005) =3D 96.5 degF with 300 psi increase=0A=A0=0AReplace an exi= sting piece of line=A0with a 3 loop coil under each seat pan, one plumbed i= nto the HI side and the other plumbed into the LO side and bleed the system= .=0A=A0=0AThere are other details but these are the basics.=0AThese are ini= tial calculations and have not yet been tested.=0A=0A- - - I consider this = solution really just an engineering exercise.=0A=A0=0ACAUTION=0AIf there is= a leak in a cylinder or the dump valve, there will still be a problem that= can render the gear inoperative=A0leaving only=A0emergency dump valve use.= =0AThe=A0action side=A0can leak into the non-action side, the pump will tur= n on to bring the action side pressure back up, the leak will continue unti= l both sides are above the pressure switch setting. Should heat soak come i= nto play after that, the pressures=A0can continue up to 1500 psi, the therm= ostatic relief valve setting of the pump.=0A=A0=0A=0A______________________= __________=0A=0A2=A0) Electric only =3D =3D =3D This will=A0address actuati= on failure in either direction. Rewire the system so the pump will run in t= he direction set by the gear switch even though both pressure switches are = open (high pressure).=A0This will build up pressure=A0 inside the pump caus= ing the shuttle to move to one side and open the other side's check valve= =A0releasing the undesired pressure.=0A=A0=0AI have designed a circuit boar= d that has=A02 relays=A0and can be wired into the pressure switches of the = existing system. It will be about 2" x 2" x 1". If I get at least 5 request= s, I will make a batch of units for those interested.=0A___________________= _____________=0A=0A=A0=0AThe=A0electric only solution can overcome the leak= =A0problem and is my desired installation.=0A=A0=0AIf anyone wants more det= ails or has comments, feel free to email me Wolfgang@MiCom.net=0A=A0=0AWolf= gang Franke=0A=0A=0A=0A --0-1518324725-1254699461=:7580 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
=0A
=0A
"Problem #2 is that vibration and pump internal le= akage can move the spool valve off it's position of all to one side or the = other while the pump is not running."
=0A
 
=0A
So t= he question still remains:  Why do some spools return to center&n= bsp;while other do not?  All are subject to vibration.  My prefer= ence would be to identify the root cause and then decide if it can or = should be addressed directly.  It may be as simple as switching&n= bsp;out a 20 cent O-ring on the spool. 
=0A
 
=0A<= DIV> 
=0A
Chris Zavatson
=0A
N91CZ
=0A
360s= td
=0A=0A

=0A
=0A
=0A= From: Wolfgang <Wolfgang= @MiCom.net>
To: Lorn = Olsen <Lorn@DynaComm.us>
Cc:<= /SPAN> Christopher.Zavatson@baesystems.com; chris_zavatson@yahoo.com; r= andystuart@hotmail.com; jmack102ea@gmail.com; JohnM@Lancair.com
Sent: Fri, October 2, 2009 6:28:25 = PM
Subject: Lancair 320/= 360 hydraulic system questions and fixes

=0A= =0A=0A
=0A

Lancair 320/360 hydr= aulic system questions and fixes

=0A
There have been instances of gear operation failure in the Lan= cer 320/360. I have looked into this, spoken with Lorn Olsen-LNC2 owner, Br= ian Anderson-product manager at OilDyne for the 108 pump,  Ross-3= 20/360 specialist at Lancair, Christopher Zavatson-Lancair owner, Randy Stu= art-Lancair owner and believe I have the answers.
=0A
 
=0A
Gear operation failure = is usually due to both HI/UP and LO/DN hydraulic pressures being above thei= r respective pressure switch settings preventing operation of the pump.&nbs= p;This happens because hydraulic fluid gets trapped in the lines and with a= temperature rise, pressures exceed normal conditions.
=0A
=  
=0A
The pump used is a= n OilDyne 108 series with the "LB" circuit. http= ://www.parker.com/literature/Literature%20Files/euro_cylinder/v4/108_1301-u= k.pdf
=0A
Earlier models were 108AM/19-CLB3V= T-11-08, Lancair # 637715 and later models are 108AMS32-CZZ3V-14-08 Lancair= # 642666. The pump has check valves that operate with a 1:5 pressure ratio= . The ZZ in the newer pump is still an LB circuit but with a slightly = modified back pressure circuit. Looking at the pressure port side of the pu= mp housing, the left port is labeled "U" and had the higher pressure output= . The right hand one is labeled "D" and has the lower pressure output. The = back pressure circuit is powered by pressure from the "D" port connect= ed to the rod side of the cylinders as shown on page 9 of the product liter= ature link above.
=0A
 
=0A=
This is problem # 1. This is back= wards from the way the 320/360 needs it ! The Lancair 320/360 requires= "U" pressure on the rod side of the cylinders to raise the gear using the = higher pressure. For the back pressure valve to operate properly, the spool= valve needs to be flipped around. This is why there have been reports of t= he spool being in backwards.
=0A
&nbs= p;
=0A
With this corrected, everything works and al= l is right with the world.
=0A
=0A
=0A
=0A
You can check your own system. You will ne= ed pressure gages in the HI and LO side to do this.  =0A
 
=0A
Put the plane up on jacks.
=0A
 
=0A
Po= wer the gear up.
=0A
With the dump valve, i= nduce a leak from HI side to LO side.
=0A
N= ote the pressure on the LO side stays at zero.
=0A
 
=0A
Power the gear down.
=0A
With the dump valve, induce a leak from HI si= de to LO side.
=0A
Note the pressure on the = HI side rises a bit and then goes back to zero.
=0A
- - - This is because the pressure has to leak back past the pump g= ears before it gets to the pressure relief valve.
=0A
 
=0A
This is expected operat= ion when the spool valve is in properly and stays where it was last pressur= ed.
=0A
=0A
=0A
=0A
Most of the time things work all right but there continue to be r= eports of gear actuation failure.
=0A
 
=0A
Problem #2 is that vibration and p= ump internal leakage can move the spool valve off it's position of all to o= ne side or the other while the pump is not running. When this happens, the = check valves close and fluid is trapped in both the HI and LO sides of the = system. Temperature increase, cylinder leakage and dump valve leakage = can all cause both sides to exceed pressure switch settings. (If there= is leakage, the pump runs and can building pressure in both sides) The the= rmostatic relief valve settings in the pump will prevent line pressure= s from exceeding about 1500 psi.
=0A
=  
=0A
 
=0A
=0A
So, the fix is to prevent the non-action side pressure from incre= asing above it's pressure switch setting due to heat soak or leakage a= nd bring it down if it does.
=0A
 
=0A
This can be accomplished in two ways.
=0A
=0A
=0A
=0A
=0A
1 ) Hydraulic only =3D =3D =3D Add an accumulator to each HI a= nd LO side to absorb the temperature induced volume/pressure increase.
=0A
 
=0A
I = initially thought 5 cu.in. units (Parker # AD007B25T9A1) with a precharge of about 1= 00-200 psi would work even though they were larger than needed.=0A
 
=0A
Upon furt= her examination, I considered a length of flexible (expandable) hose added = to the system since that would be much easier to install. I just needed to = figure out the required length. After rounding up expansion numbe= rs from AeroQuip on their 303-5 and 303-8 hose and other details;=0A
 
=0A
=0A303-5 ID=3D1/4"
=0A
303-5 ho= se expansion =3D 0.094cc / in at 1000 psi
=0A
=0A
303-5 hose expansion =3D 0.123cc / in at= 2000 psi
=0A
303-5 hose expansion =3D = 0.149cc / in at 3000 psi
=0A
 
=0A
303-8 ID = =3D 13/32"
303-8 hose expansion =3D 0.100cc / in at 600 psi
=0A
303-8 hose expansion =3D 0.137cc / in at= 1250 psi
=0A
303-8 hose expansion =3D = 0.171cc / in at 2000 psi
=0A
 =0A
=0A
Hydraulic fluid volume in the LNC2 is ab= out 27 cu in ;  6.4 cu in in the lines= , ; 20.6 cu in the actuators with door actu= ators
=0A
Hydraulic fluid thermal expansion = coefficient =3D .0005 / deg.F
=0A
=0A
Aluminum thermal expansion coefficient =3D .0000123 / deg.F (= negligible for this purpose)
=0A
Modulus of = elasticity of hydraulic fluid =3D 250,000 (compression under pressure = - psi per percent reduction in volume - negligible for this purpo= se)
=0A
 
=0A
I calculated that about 8ft of 303-5 with AN4 fittings would prov= ide the desired volume expansion from heat soak.
=0A
 
=0A
Fluid in the non-action= side of the system =3D 3.2 cu in.
=0A
= 8ft of 303-5 line =3D 4.71 cu in
=0A
Fl= uid in the non-action side of the system with added line =3D 7.9 cu in= (ignoring volume of removed line segment)
=0A
Extrapolated volume increase in the added line at 300 psi =3D 0.0= 65cc / in
=0A
Volume increase =3D 0.065 = ;/ 2.54^3 x 96 =3D 0.381 cu in
=0A
Delta T a= llowance =3D 0.381 / (7.9 x 0.0005) =3D 96.5 degF with 300 psi increase
=0A
 
=0A
R= eplace an existing piece of line with a 3 loop coil under each seat pa= n, one plumbed into the HI side and the other plumbed into the LO side and = bleed the system.
=0A
 
=0A=
There are other details but these are the basics.
=0A
These are initial calculations and have not y= et been tested.
=0A
 
=0A
- - = - I consider this solution really just an engineering exercise.=0A
=0A
 =0A
CAUTION
=0A
If th= ere is a leak in a cylinder or the dump valve, there will still be a proble= m that can render the gear inoperative leaving only emergency dum= p valve use.
=0A
The action side c= an leak into the non-action side, the pump will turn on to bring the action= side pressure back up, the leak will continue until both sides are above t= he pressure switch setting. Should heat soak come into play after that, the= pressures can continue up to 1500 psi, the thermostatic relief valve = setting of the pump.
=0A
 
= =0A
=0A
=0A
=0A
= 2 ) Electric only =3D =3D =3D This will address actuation failure= in either direction. Rewire the system so the pump will run in the directi= on set by the gear switch even though both pressure switches are open (high= pressure). This will build up pressure  in= side the pump causing the shuttle to move to one side and open the other si= de's check valve releasing the undesired pressure.
=0A 
=0A
I have designed a= circuit board that has 2 relays and can be wired into the pressu= re switches of the existing system. It will be about 2" x 2" x 1". If I get= at least 5 requests, I will make a batch of units for those interested. =0A
=0A
=0A
&n= bsp;
=0A
The electric only solution can overco= me the leak problem and is my desired installation.
=0A 
=0A
=0A
<= /DIV>
=0A
If anyone wants mor= e details or has comments, feel free to email me Wolfgang@MiCom.net
=0A
&nbs= p;
=0A
Wolfgang Franke
=0A
 

=0A=0A --0-1518324725-1254699461=:7580--