Olympus BH2 Series Installation instructions

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CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlockRevision2Page1of23
CompleteTeardown,Cleaning,and
ReassemblyoftheOlympusBH‐2
SlidingFocusBlock
(Revision2)
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Copyright©2017,2018CarlHunsinger
Allrightsreserved.Thisdocumentmaynotbereproducedordistributed,inwholeorinpart,foranycommercial
purposewithouttheexpresswrittenconsentoftheauthor(car[email protected]).Permissionisherebygrantedto
distributethisPDFdocumentinitsentiretyforpersonal,non‐commercialpurposesonly,providedthatthecontentsare
notmodifiedinanyway,includingthecopyrightnoticescontainedherein.Thisdocumentmaybefreelydistributedon
WWW,FTP,orBBSsitesinaccordancewiththeserestrictions.Thecontentofthisdocumentisprovidedfor
informationalpurposesonly,withnoexpressedorimpliedwarrantieswhatsoever,including,butnotlimitedto,
function,suitability,safety,accuracy,orcompletenessofinformation.
RevisionHistory
RevisionDescriptionofChangesDate
1***InitialRelease***September4,2017
2Addedremovalprocedureforthebottomdustguardandmademinorrevisions.April13,2018
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CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlockRevision2Page2of23
TableofContents
Introduction............................................................................................................................................................................6
ScopeofthisDocument..........................................................................................................................................................6
ACautionRegardingStiffFocusMechanisms.........................................................................................................................6
ToolsNeeded..........................................................................................................................................................................6
AFewWordsaboutJISScrews...............................................................................................................................................6
SuppliesNeeded.....................................................................................................................................................................6
RecommendedSolvents.........................................................................................................................................................6
SafetyConsiderationswithSolvents.......................................................................................................................................6
SolventCompatibilitywithPartsandFinishes........................................................................................................................7
RecommendedLubricants......................................................................................................................................................7
LabelPartsforIdentificationandReassembly........................................................................................................................7
PartofaComprehensiveFocusOverhaul...............................................................................................................................7
ProtecttheExposedMountingDovetails...............................................................................................................................7
SeparatetheArmfromtheBase............................................................................................................................................8
RemovetheLamphouse.....................................................................................................................................................8
RemovetheElectricalBase.................................................................................................................................................8
RemovetheArmfromtheBase..........................................................................................................................................8
DisassembletheSlidingFocusBlock.......................................................................................................................................9
RemovetheTrimCover......................................................................................................................................................9
LoosentheScrewsTensioningtheSlideMechanism.........................................................................................................9
RemovetheFocusBlockAssemblyfromtheArm..............................................................................................................9
CleantheVariousSlideComponents....................................................................................................................................10
RemovetheGuideRailsfromtheArmCasting................................................................................................................10
RemoveandReinstalltheBottomDustCover..................................................................................................................11
RemovetheGuideRailsfromtheFocusBlock.................................................................................................................11
RemovetheGuideRailsfromtheGuideBlock.................................................................................................................12
CleantheCylindricalRollers..............................................................................................................................................12
ReassembletheSlidingFocusBlock
......................................................................................................................................12
ReinstalltheGuideRailsintotheArmCasting.................................................................................................................12
ReinstalltheGuideRailsintotheFocusBlock..................................................................................................................13
ReinstalltheGuideRailsintotheGuideBlock..................................................................................................................13
ApplyGreasetotheGuideRails(Optional)......................................................................................................................14
PlacetheGuideBlockintoPositionontheFocusBlock...................................................................................................14
PlaceCylindricalRollersontoLowerGuideRailsofArm..................................................................................................14
PlaceFocusBlockAssemblyontoCylindricalRollers........................................................................................................15
PlaceCylindricalRollersontotheUpperGuideRails........................................................................................................15
MounttheGuideBlockintoPosition................................................................................................................................16
AdjustforNoLateralPlayintheSlidingFocusBlock........................................................................................................16
SecuretheGuideBlockinPosition...................................................................................................................................17

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CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlockRevision2Page3of23
TesttheFocusBlockforFreedomofMotion.......................................................................................................................17
ReinstalltheTrimCover....................................................................................................................................................17
ReinstalltheArmontotheBase...........................................................................................................................................18
ReinstalltheElectricalBase..............................................................................................................................................18
ContinuewiththeCoaxialFocusOverhaul...........................................................................................................................19
OriginalOlympusDocumentation........................................................................................................................................19
HowtoContacttheAuthor
...................................................................................................................................................19
Appendix1–HowtoInstallGuideRailsintheSlidingFocusBlockMechanism..................................................................20
PlacementofGuideRailsintheSideGrooves......................................................................................................................20
HoldingtheGuideRailsinPlaceforReassembly..............................................................................................................20
ReinstallingGuideRailsintotheGuideBlock.......................................................................................................................20
CleantheOldGreasefromtheSlideParts.......................................................................................................................20
ApplyHeavyGreasetoBothEndsoftheGuideBlock......................................................................................................20
SettheGuideRailsintotheGreasedGuide......................................................................................................................21
CleanGreaseafterReinstallingtheGuideRails................................................................................................................21
ThePreparedGuideBlockisReadytobeReinstalled......................................................................................................22
Appendix2–SourcesforReplacementToolsandSuppliesReferencedInthisDocument.................................................23
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CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlockRevision2Page4of23
TableofFigures
Figure1–HeadofatypicalJISscrew.....................................................................................................................................6
Figure2–Protectthetopofthearmfromdust....................................................................................................................7
Figure3–Removethelamphousefromthebase..................................................................................................................8
Figure4–BottomviewoftheBHT/BHTUelectricalbase......................................................................................................8
Figure5–Lightpre‐setcontrolandpre‐setswitch................................................................................................................8
Figure6–Removescrewssecuringthearmtothebase.......................................................................................................8
Figure7–Separatethearmfromthebase............................................................................................................................8
Figure8–Removescrewssecuringthetrimcover................................................................................................................9
Figure9–Removetheloosetrimcoverfromthearm...........................................................................................................9
Figure10–Loosenscrewssecuringguideblockinplace.......................................................................................................9
Figure11–Loosenscrewstensioningslidemechanism........................................................................................................9
Figure12–Withdrawfocusblockassemblyfromthearm....................................................................................................9
Figure13–Removescrewssecuringtheguideblock..........................................................................................................10
Figure14–Removetheguideblockfromthefocusblock...................................................................................................10
Figure15–Thecomponentsofthefocusblockassembly...................................................................................................10
Figure16–Removethebrassshimsfromthefocusblock..................................................................................................10
Figure17–Removescrewsandwedgenuts........................................................................................................................10
Figure18–Removefourguiderailsfromthearmcasting...................................................................................................10
Figure19–Cleangreasefromtheguiderails......................................................................................................................11
Figure20–Cleangreasefromthesidegroovesinthearm.................................................................................................11
Figure21–Removescrewssecuringbottomdustcover.....................................................................................................11
Figure22–Removethebottomdustcover.........................................................................................................................11
Figure23–Removetwoguiderailsfromthefocusblock....................................................................................................11
Figure24–Cleangreasefromsidegrooveinfocusblock....................................................................................................12
Figure25–Removeguiderailsfromtheguideblock...........................................................................................................12
Figure26–Cleangreasefromsidegrooveinguideblock...................................................................................................12
Figure27–Soaktherollersinsolventtoremovegrease.....................................................................................................12
Figure28–Reinstallthelongguiderailsintothearm.........................................................................................................12
Figure29–Scrubgreasefromguiderailsandarm..............................................................................................................12
Figure30–Guiderailsinstalledintothearmcasting...........................................................................................................13
Figure31–Reinstallshortguiderailsintothefocusblock..................................................................................................13
Figure32–Scrubgreasefromguiderailsandfocusblock...................................................................................................13
Figure33–Guiderailsinstalledintothefocusblock...........................................................................................................13
Figure34–Reinstallshortguiderailsintotheguideblock..................................................................................................13
Figure35–Scrubgreasefromguiderailsandguideblock..................................................................................................13
Figure36–Guiderailsinstalledintotheguideblock...........................................................................................................14
Figure37–Reinstallthebrassshimsontothefocusblock..................................................................................................14
Figure38–Cleanexposedgreasefromthefocusblock......................................................................................................14
Figure39–Reinstallguideblockontothefocusblock.........................................................................................................14
Figure40–Looselyengagescrewswiththewedgenuts.....................................................................................................14
Figure41–Placerollersandrodontobottomguiderails...................................................................................................15
Figure42–Placefocusblockassemblyontorollers............................................................................................................15
Figure43–Withdrawtheguideblockabouthalfway..........................................................................................................15
Figure44–Placefourrollersontheupperguiderails.........................................................................................................15
Figure45–Pushcylindricalrollersintoguide‐railchannel..................................................................................................15
Figure46–Pushthespacerrodintoguide‐railchannel......................................................................................................16

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CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlockRevision2Page5of23
Figure47–Placeremainingrollersontoupperguiderails..................................................................................................16
Figure48–Pushguideblockandrollersintothechannel...................................................................................................16
Figure49–Reinstallscrewstosecuretheguideblock........................................................................................................16
Figure50–Adjustforfreemotionwithoutlateralplay.......................................................................................................17
Figure51–Securetheguideblockinposition.....................................................................................................................17
Figure52–Testtheslidingfocusblockforpropermotion..................................................................................................17
Figure53–Repositiontrimcoverontothearmcasting......................................................................................................17
Figure54–Reinstallscrewstosecurethetrimcover..........................................................................................................17
Figure55–Placethearmflatontheworksurface..............................................................................................................18
Figure56–Alignholesinthebasewithholesinthearm....................................................................................................18
Figure57–Attachthebaseontothearmofthestand........................................................................................................18
Figure58–Securethearmontothebaseofthestand.......................................................................................................18
Figure59–Reinstallscrewstosecuretheelectricalbase....................................................................................................18
Figure60–TheOlympusBH2(BHS)repairmanual.............................................................................................................19
Figure61–Correctorientationoftheguiderails.................................................................................................................20
Figure62–Thoroughlycleantheguiderails........................................................................................................................20
Figure63–Thoroughlycleantheguideblock......................................................................................................................20
Figure64–Applygreasetobothendsoftheguideblock...................................................................................................21
Figure65–Placefirstguiderailintotheguideblock...........................................................................................................21
Figure66–Setthefirstguiderailintothegrease................................................................................................................21
Figure67–Placesecondguiderailintotheguideblock......................................................................................................21
Figure68–Setthesecondguiderailintothegrease...........................................................................................................21
Figure69–Scrubanyvisiblegreasefromtheguiderails.....................................................................................................21
Figure70–Preparedguideblockreadyforreinstallation...................................................................................................22
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CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page6of23 
Introduction
ThemicroscopesintheOlympusBH‐2line(BHS,BHSU,
BHT,andBHTU)havelargelybeenreplacedinthe
professionalandclinicalworld,duetotheiradvancing
ageandthelackofrepairpartsfromOlympus.Agreat
manyofthesemicroscopeswereproducedintheirday,
andbecauseofthisaretheyreadilyavailableonthe
usedmarketforveryreasonableprices.Thankstotheir
excellentbuildqualityandsolidopticalperformance,
thesescopesarenowverypopularwithhobbyists,
providinganaffordable,high‐qualityalternativetothe
Chinese‐madescopesprevalenttoday.Oneproblem
thatmightbeencounteredwhenpurchasingoneof
thesescopesisthatthefocusactionmaybestiffdueto
thedecades‐oldgreaseinthecoaxialfocusmechanism
andintheslidingfocusblockmechanism.
ScopeofthisDocument
Thisdocumentdescribesthecompleteteardown,
cleaning,andreassemblyoftheslidingfocusblock
mechanisminanOlympusBHTUstand.Sincethe
variousBH‐2standsusethesameslidingfocusblockas
theBHTU,thisdocumentshouldallowahobbyistwith
reasonablemechanicalabilitiestoservicethesliding
focusblockonanyoftheBH‐2stands.Notethatthis
documentcoversthespecificconfigurationofthe
slidingfocusblockmechanismwhichutilizescrossed
rollerstoprovidesmoothlinearmotionofthefocus
block.ThevastmajorityoftheBH‐2standsthatwere
everproducedusedthismechanicalconfiguration.The
veryearlystandsthatweremanufactured(i.e.,thefirst
200orso)utilizedbearingballsinsteadofcrossed
rollersintheslidemechanism,andtheseearlyunitsare
outsidethescopeofthisdocument
1
.
ACautionRegardingStiffFocusMechanisms
AvoidturningthefocusknobsonanyBH‐2microscope
standwhosefocusmechanismfeelsabnormallystiff.
Turningtheseknobswhenthereisexcessresistancein
themechanism,suchasmaybecausedbydriedgrease,
putshighstressesontheplasticdrivegearsinthefine‐
focusmechanism,andthesecanbedamagedifthese
stressesaretoohigh.
ToolsNeeded
Thefollowingtoolswillbeneededtocompletethe
teardown,cleaning,andreassemblyoftheslidingfocus
blockmechanisminaBH‐2microscopestand:
Allenwrenchordriver:2.5mm(item1ofAppendix2)

1
Afuturerevisionofthisdocumentmayincludetheball‐slideconfiguration,
ifasuitablestandeverbecomesavailableforthispurpose.
Allenwrenchordriver:4.0mm(item2ofAppendix2)
Allenwrenchordriver:5.0mm,(item3ofAppendix2)
Screwdriverset,JIS(item4ofAppendix2)
AFewWordsaboutJISScrews
ScrewswithJISheadsarefrequentlyfoundinmuchof
theequipmentdesignedandmanufacturedinJapan.
JISscrewslookverymuchlikestandardPhillipsscrews,
buttheydifferinthatJISscrewsweredesignedtonot
cam‐outundertorque,whereasPhillipsscrewswere
designedtointentionallycam‐outasameanstolimit
thetorqueappliedtothefasteners.Becauseofthis
crucialdifferenceinthegeometryofthetwoscrew
types,JISscrewswillbedamagedbystandardPhillips
driversiftoomuchtorqueisapplied.JISscrewscan
usuallybeidentifiedbythepresenceofasingledot(or
byan“X”)stampedintooneofthefourquadrantsof
thecross‐pointdepression(seeFigure1).

Figure1–HeadofatypicalJISscrew
SuppliesNeeded
Thefollowingsupplieswillbeneededtocompletethe
teardown,cleaning,andreassemblyoftheslidingfocus
blockmechanisminaBH‐2microscopestand:
Cleaningsolvents(seeRecommendedSolventsbelow)
Cottonswabs
Lubricants(seeRecommendedLubricantsbelow)
Tissues,oilfree
RecommendedSolvents
Sometypeofcleaningsolventwillbeneededtoremove
theoldgreasefromthevariouscomponentsofthe
slidingfocusblockmechanism.Solventsthatcanbe
usedareacetone(commonlysoldasfingernailpolish
remover),diethylether,heptane,hexane,mineral
spirits,turpentine,andxylene.
SafetyConsiderationswithSolvents
Regardlessofwhichsolventischosen,makesurethat
adequateventilationispresentduringthecleaning


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlockRevision2Page7of23
process,andthatanynecessarypersonalprotective
equipmentisutilizedtominimizeexposure.Consultthe
MSDSsheetbeforeusinganyunfamiliarsolvents.Many
ofthesolventslistedaboveareflammableandtheir
vaporsmayrepresentanexplosionhazardif
mishandled.Whicheversolventsarechosen,besureto
followallofthemanufacturer’sinstructionsandsafety
precautions.
SolventCompatibilitywithPartsandFinishes
Manysolventswilldamagethefinishofpainted
surfaces(isopropylalcoholor409Cleanermaybesafely
usedtocleanmostpaintedsurfaces)orwilldissolveor
damageplasticparts.Donotallowuntestedsolventsto
contactanyplasticpartsoranypaintedsurfaces.
Beforeusingasolventtocleanplasticpartsorpainted
surfaces,testasmallamountofthesolventinan
inconspicuousarea(suchasinsideaplasticknob)to
ensurecompatibilitywiththeplasticpartorpainted
surface.Neverusexylenetocleannylonparts,as
xylenedissolvesnylon.Isopropylalcoholand
trichloroethylenewillcauseswellingofnylondueto
solventabsorption.Thelistofsolventsgenerally
consideredsafefornylonincludesacetone,diethyl
ether,heptane,mineralspirits,naphthalene,and
turpentine.
RecommendedLubricants
TheOlympusBH2(BHS)repairmanual(seetheOriginal
OlympusDocumentationsectionofthisdocument)
recommendsusinggreaseintheslidingfocusblock
mechanism.However,basedondecadesofexperience
servicingBH‐2equipmentinthefield,somemicroscope
repairtechniciansrecommendomittingthegrease
entirelyfromtheslidingfocusblock,inordertoreduce
thefoulingofthemechanismwhichcanoccurifdust
anddebrisaccumulatesinthegreasedslides,aswellas
reducinganystiffnessorsluggishnessthatwillresult
fromthickeningofthegrease.Giventhisconflicting
guidance,considerthatgreasemaybeappliedtothe
slidepertheOlympusguidance,attheriskofrequiring
morefrequentmaintenancetokeepthemechanism
cleanandfreelymoving,andgreasemaybeomitted,at
theriskofmorelong‐termwearofthemechanical
components.MobilPolyrexTMEMorMolykote®44
(items7and5ofAppendix2)arerecommendedif
lubricationisdesiredintheslide.Regardlessof
whetherornotlubricationisusedintheslide,aheavy
greasesuchasDowMolykote®111(item6ofAppendix
2)shouldbeusedtoholdtheguiderailsinplaceduring
reassembly,andanyexcessgreaseremainingafterthe
guiderailshavebeeninstalledshouldbethoroughly
removedbeforeproceedingwiththereassemblyofthe
slidingfocusblockmechanism.
LabelPartsforIdentificationandReassembly
Therearemanysmallpartsthatmakeupthesliding
focusblockmechanism.Itiscriticalthatthesebe
baggedandtaggedastheyareremovedtoprevent
themfromgettinglostandtofacilitatetheirproper
identificationduringreassembly.
PartofaComprehensiveFocusOverhaul
Maintenanceoftheslidingfocusblockisbest
performedaspartofacomprehensiveoverhaulofthe
entirefocusmechanism.Itisbestperformedaftera
teardownofthecoaxialfocusmechanismhasbeen
performed,sincethisserviceiseasiertoperformwhile
thefocusknobsandotherfocuspartsarenotpresent
onthearm.Accordingly,thisdocumentdescribes(and
theaccompanyingphotographsshow)theservicebeing
performedonastandthathashadthecoaxialfocus
blockcompletelydisassembled,pertheComplete
Teardown,Cleaning,andReassemblyoftheBH‐2
CoaxialFocusMechanismdocument.Inalmostevery
casewheretheslidingfocusblockissluggishandneeds
tobeserviced,thecoaxialfocusmechanismisalsoin
needofasimilarservice,soitmakessensetoperform
bothrepairsatthesametime.
ProtecttheExposedMountingDovetails
Beforeproceedingwiththeteardowndescribedinthis
document,coverthetopofthemicroscopearm(i.e.,
theexposedmountingdovetailsfortheviewinghead
andnosepiece,ifapplicable)withacleanplasticbag
andsecurethiswitharubberbandoradhesivetapeto
keepdustout(seeFigure2).Thisisespecially
importantonBHSUandBHTUstandswhichhavean
opticalcorrectionlenslocatedjustbelowtheviewing
headtocorrectforthedifferenceintubelength
introducedwiththereversednosepiece.

Figure2–Protectthetopofthearmfromdust


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page8of23 
SeparatetheArmfromtheBase
Separatethearmfromthebaseofthestandperthe
followingprocedure.
RemovetheLamphouse
Removethelamphousefromthebasebygraspingit
andpullingitstraightback(seeFigure3).Donottouch
thehalogenlampwithyourfingers,asoilsfromyour
skinmaycauseprematurefailureofthebulb.Ifthe
bulbisaccidentallytouched,cleanitwithisopropyl
alcohol.

Figure3–Removethelamphousefromthebase
RemovetheElectricalBase
Carefullyturnthestandupsidedown.Usea4mm(or
5/32”)AllenwrenchordrivertoremovethefourM5x12
hex,socket‐headcapscrewsandtheassociated
washersfromthebottomofthestand(seeFigure4).

Figure4–BottomviewoftheBHT/BHTUelectricalbase
Holdtheelectricalbaseinplaceandsetthestandinits
normaluprightpositiononaflatsurface,beingcareful
nottolettheelectricalbaseshiftasyoudoso.Liftthe
standfromtheelectricalbasebygraspingthearmand
liftingstraightupuntilthebottomofthestandwell
clearstheelectricalbase.Ifthestandcontainsalight‐
presetcontrol/switch(seeFigure5),besureto
disengagethepresetcontrol/switchfromthenotchin
thesideofthebase
2
beforeliftingthestandclearofthe
electricalbase.Settheelectricalbaseaside.

Figure5–Lightpre‐setcontrolandpre‐setswitch
RemovetheArmfromtheBase
Laythestandonitsback.Usea5mmAllenwrenchor
drivertoremovethefourM6x25hex,socket‐headcap
screwssecuringthearmtothebase(seeFigure6)and
separatethearmfromthebase(seeFigure7).

Figure6–Removescrewssecuringthearmtothebase

Figure7–Separatethearmfromthebase

2
Orunplugthetwoelectricalconnectorsfromtheprintedcircuitboard.


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page9of23 
Withtheelectricalbaseremoved,fragilelighting
componentsareexposedontheopenbottomofthe
basewhichmaybedamagedifthebaseisnotplacedon
asuitableclutter‐freesurface.Placethebaseinits
normaluprightpositiononaclean,flatsurface
someplaceoutofharm’swayandwheredustand
debriswillnotaccumulateontheexposedlighting
components.
DisassembletheSlidingFocusBlock
Disassembletheslidingfocusblockmechanismperthe
followingprocedure.
RemovetheTrimCover
UseasuitableJISscrewdrivertoremovethefourM2x4
screwssecuringtheU‐shapedtrimcoverontothearm
casting(seeFigure8).

Figure8–Removescrewssecuringthetrimcover
Removethe(nowloose)trimcoverfromthearm
casting(seeFigure9).

Figure9–Removetheloosetrimcoverfromthearm
LoosentheScrewsTensioningtheSlideMechanism
Usea2.5mmAllenwrenchordrivertoloosen(butdo
notremove)thethreeM3x12hex,socket‐headcap
screwssecuringtheguideblockintopositiononthe
backsideofthefocusblock(seeFigure10).

Figure10–Loosenscrewssecuringguideblockinplace
Usea2.5mmAllenwrenchordrivertoloosen(butdo
notremove)thetwoM3x16hex,socket‐headcap
screwstensioningtheslidemechanism(seeFigure11).

Figure11–Loosenscrewstensioningslidemechanism
RemovetheFocusBlockAssemblyfromtheArm
Carefullyslidethefocusblock(withattachedguide
block)outthebottomofthearm(seeFigure12),being
carefultonotloseanyofthecylindricalrollersorspacer
rodsintheprocess(thereareeightrollersandone
spacerrodoneachsideoftheslidemechanism).

Figure12–Withdrawfocusblockassemblyfromthearm


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page10of23 
Usea2.5mmAllenwrenchordrivertoremovethe
threeM3x12hex,socket‐headcapscrewssecuringthe
guideblocktothebacksideofthefocusblock(see
Figure13).

Figure13–Removescrewssecuringtheguideblock
Separatethe(nowloose)guideblockfromthefocus
block(seeFigure14).

Figure14–Removetheguideblockfromthefocusblock
Thecomponentsofthefocusblockassemblyareshown
inFigure15.

Figure15–Thecomponentsofthefocusblockassembly
Removethetwobrassshimsfromtheguideblock(see
Figure16).

Figure16–Removethebrassshimsfromthefocusblock
Usea2.5mmAllenwrenchordrivertounscrewthetwo
M3x16hex,socket‐headcapscrewsfromthewedge
nuts,andremovethe(nowloose)wedgenuts(see
Figure17).

Figure17–Removescrewsandwedgenuts
CleantheVariousSlideComponents
Disassembleandcleanthevariouscomponentsofthe
slidingfocusblockmechanismperthefollowing
procedure.
RemovetheGuideRailsfromtheArmCasting
Removethefourlongguiderailsfromthetwoside
groovesinthearmcasting(seeFigure18).

Figure18–Removefourguiderailsfromthearmcasting


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page11of23 
Useasuitablesolvent(e.g.,acetone)toremoveany
greasefromthefourlongguiderails(seeFigure19)and
fromthesidegroovesinthearmcasting(seeFigure20).

Figure19–Cleangreasefromtheguiderails

Figure20–Cleangreasefromthesidegroovesinthearm
RemoveandReinstalltheBottomDustCover
Thefunctionofthebottomdustcover,whichisnot
presentonallBH‐2stands,istopreventdustanddebris
fromenteringtheopeningatthebottomofthearm
(wherethearmattachestothebasecasting)and
foulingthemechanismoftheslidingfocusblock.
Althoughthisdustcover,ifpresent,doesnotneedtobe
removedtoperformthemaintenancedescribedinthis
document,itsremovalmaybedesirabletoallowfora
more‐thoroughcleaningofanydustanddebris
accumulationintheareaofthedustcover,andthe
removalprocedureisincludedinthisdocumentforthe
sakeofcompleteness.
UseasuitableJISscrewdrivertoremovethetwoM2x4
screwssecuringthedustcoverontothebottomofthe
armcasting(seeFigure21).Liftandremovethedust
cover(seeFigure22)andcleananydustanddebris
fromthecoverandfromtheassociatedareaofthearm
casting.Repositionthedustcoverinplaceandsecureit
tothearmcastingwiththetwoM2x4screws.

Figure21–Removescrewssecuringbottomdustcover

Figure22–Removethebottomdustcover
RemovetheGuideRailsfromtheFocusBlock
Removethetwoshortguiderailsfromthesidegroove
inthefocusblock(seeFigure23).

Figure23–Removetwoguiderailsfromthefocusblock
Useasuitablesolvent(e.g.,acetone)toremoveany
greasefromtwoshortguiderails(seeFigure19)and
fromthesidegrooveinthefocusblock(seeFigure24).



CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page12of23 

Figure24–Cleangreasefromsidegrooveinfocusblock
RemovetheGuideRailsfromtheGuideBlock
Removethetwoshortguiderailsfromthesidegroove
intheguideblock(seeFigure25).

Figure25–Removeguiderailsfromtheguideblock
Useasuitablesolvent(e.g.,acetone)toremoveany
greasefromtwoshortguiderails(seeFigure19)and
fromthesidegrooveintheguideblock(seeFigure26).

Figure26–Cleangreasefromsidegrooveinguideblock
CleantheCylindricalRollers
Soakthecylindricalrollersinasuitablesolvent(e.g.,
acetone)toremoveallgreasefromtherollers(see
Figure27).

Figure27–Soaktherollersinsolventtoremovegrease
ReassembletheSlidingFocusBlock
Reassembletheslidingfocusblockmechanismperthe
followingprocedure.
ReinstalltheGuideRailsintotheArmCasting
PertheproceduredescribedinAppendix1ofthis
document,reinstallthefourlongguiderailsintothe
twosidegroovesofthearmcasting(seeFigure28)and
removeanyexposedgreasefromthefourguiderails
(seeFigure29andFigure30).

Figure28–Reinstallthelongguiderailsintothearm

Figure29–Scrubgreasefromguiderailsandarm


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page13of23 


Figure30–Guiderailsinstalledintothearmcasting
ReinstalltheGuideRailsintotheFocusBlock
PertheproceduredescribedinAppendix1ofthis
document,reinstalltwooftheshortguiderailsintothe
sidegrooveinthefocusblock(seeFigure31)and
removeanyexposedgreasefromthetwoguiderails
(seeFigure32andFigure33).

Figure31–Reinstallshortguiderailsintothefocusblock

Figure32–Scrubgreasefromguiderailsandfocusblock

Figure33–Guiderailsinstalledintothefocusblock
ReinstalltheGuideRailsintotheGuideBlock
PertheproceduredescribedinAppendix1ofthis
document,reinstallthetworemainingshortguiderails
intothesidegrooveintheguideblock(seeFigure34)
andremoveanyexposedgreasefromthetwoguide
rails(seeFigure35andFigure36).

Figure34–Reinstallshortguiderailsintotheguideblock

Figure35–Scrubgreasefromguiderailsandguideblock


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page14of23 

Figure36–Guiderailsinstalledintotheguideblock
ApplyGreasetotheGuideRails(Optional)
IFGREASEISTOBEUSEDINTHESLIDINGFOCUSBLOCK(RECOMMENDED)
Lightlycoattheexposedsurfacesofthefourlongguide
railsinthearm,thetwoshortguiderailsintheguide
block,andthetwoshortguiderailsinthefocusblock
withsuitablegrease(item5or7ofAppendix2).
PlacetheGuideBlockintoPositionontheFocusBlock
Reinstallthetwobrassshimsontothefocusblock,using
asmalldabofheavygrease(item6ofAppendix2)at
eachendoftheshimstoholdtheminpositionduring
thesubsequentreassemblysteps(seeFigure37).

Figure37–Reinstallthebrassshimsontothefocusblock
Afterplacingthetwobrassshimsintopositiononthe
backofthefocusblock,wipeawayanyexposedgrease
withacleandrytissue(seeFigure38).

Figure38–Cleanexposedgreasefromthefocusblock
Placetheguideblock,withtwoshortguiderails
installedintoitssidegroove,intopositionontopofthe
twobrassshimssittingonthefocusblock(seeFigure
39).Notetheproperorientationofthebevelededgeof
theguideblock(seeFigure40).

Figure39–Reinstallguideblockontothefocusblock
PlacetwoM3X16hex,socket‐headcapscrewsthrough
theholesinthefocusblock,andusea2.5mmAllen
wrenchordrivertolooselyengagethethreadsofthe
screwswiththetwowedgenuts(seeFigure40).

Figure40–Looselyengagescrewswiththewedgenuts
PlaceCylindricalRollersontoLowerGuideRailsofArm
IFGREASEISTOBEUSEDINTHESLIDINGFOCUSBLOCK(RECOMMENDED):
Lightlycoateightofthecylindricalrollersandoneofthe
plasticspacerrodswithsuitablegrease(item5or7of
Appendix2).Placetheseeightgreasedcylindrical
rollersandthegreasedplasticspacerrodontothe
greasedguiderailsinthebottomchannelofthearm
casting(seeFigure41,shownwithoutgreasefor
clarity).Notethealternatingorientationoftherollers.
IFGREASEISNOTTOBEUSEDINTHESLIDINGFOCUSBLOCK:
Placeeightofthecylindricalrollersandtheoneofthe
plasticspacerrodsontotheguiderailsinthebottom
channelofthearmcasting(seeFigure41).Notethe
alternatingorientationoftherollers.


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page15of23 

Figure41–Placerollersandrodontobottomguiderails
PlaceFocusBlockAssemblyontoCylindricalRollers
Carefullyplacethefocusblockassembly,withtheguide
blockheldlooselyinplaceonthebacksideofthefocus
block,ontothecylindricalrollersontheguiderailsin
thebottomgrooveofthearmcasting(seeFigure42).

Figure42–Placefocusblockassemblyontorollers
Withdrawabouthalfthelengthoftheguideblockfrom
behindthefocusblock,makingsuretonotdisturbthe
positioningofthetwobrassshimsstuckontotheback
sideofthefocusblockortheguiderailsseatedinthe
sidegrooveoftheguideblock(seeFigure43).

Figure43–Withdrawtheguideblockabouthalfway
PlaceCylindricalRollersontotheUpperGuideRails
IFGREASEISTOBEUSEDINTHESLIDINGFOCUSBLOCK(RECOMMENDED):
Lightlycoatfourofthecylindricalrollersandthe
remainingplasticspacerrodwithasuitablegrease
(item5or7ofAppendix2).Placethesefourgreased
cylindricalrollersontothegreasedguiderailsinthe
grooveontopoftheguideblock,wheretheguideblock
isprotrudingfromthebottomofthearmcasting(see
Figure44,shownwithoutgreaseforclarity).Orientthe
rollersasshowninthephotoinset.
IFGREASEISNOTTOBEUSEDINTHESLIDINGFOCUSBLOCK:
Placefourofthecylindricalrollersontotheguiderails
inthegrooveontopoftheguideblock,wheretheguide
blockisprotrudingfromthebottomofthearmcasting
(seeFigure44).Orienttherollersasshowninthe
photoinset.

Figure44–Placefourrollersontheupperguiderails
Usetheremainingplasticspacerrodtocarefullypush
thefourcylindricalrollersintothechannelformedby
thefourguiderails(twointhefocusblockandtwoin
thearmcasting),makingsurethattherollersdonot
comeoutofpositionontheguiderailsastheyare
pushedintothechannel(seeFigure45).

Figure45–Pushcylindricalrollersintoguide‐railchannel


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page16of23 
Afterthefourcylindricalrollershavebeenpushedinto
thechannelformedbythefourguiderails,continue
pushingtheplasticspacerrodintotheopeninguntiljust
thetipisvisible(seeFigure46).

Figure46–Pushthespacerrodintoguide‐railchannel
IFGREASEISTOBEUSEDINTHESLIDINGFOCUSBLOCK(RECOMMENDED):
Lightlycoattheremainingfourcylindricalrollerswitha
suitablegrease(item5or7ofAppendix2).Placethese
fourgreasedcylindricalrollersontothegreasedguide
railsinthesidechanneloftheguideblockprotruding
fromthebottomofthearm(seeFigure47,shown
withoutgreaseforclarity).Orienttherollersasshown.
IFGREASEISNOTTOBEUSEDINTHESLIDINGFOCUSBLOCK:
Placethefourremainingcylindricalrollersontothe
guiderailsinthesidechanneloftheguideblock
protrudingfromthebottomofthearm(seeFigure47).
Orienttherollersasshown.

Figure47–Placeremainingrollersontoupperguiderails
Carefullypushtheprotrudingguideblock(withthe
cylindricalrollersandspacerrodsittingontopofthe
guiderails)intopositionbehindthefocusblock,making
surethattherollersdonotcomeoutofpositiononthe
guiderailsastheyarepushedintothechannel.Align
thethreeholesinthefocusblockwiththetappedholes
intheguideblock(seeFigure48).

Figure48–Pushguideblockandrollersintothechannel
MounttheGuideBlockintoPosition
Holdtheguideblockinpositionsuchthatthethree
holesinthefocusblockarealignedwiththetapped
holesintheguideblock.Makesurethatthebrass
shimsarenotvisiblethroughthethreeholesinthe
focusblock,otherwisethescrewsmaydamagethese
shimswhentheyarereinstalled(ifnecessary,usea
toothpickorsomeotherpointedtooltorepositionthe
shimssothatthescrewswillnotdamagetheshims
whentheyarereinstalled).Whileholdingtheguide
blockinthisposition,usea2.5mmAllenwrenchor
drivertoreinstallthreeM3x12hex,socket‐headcap
screwstosecuretheguideblocktothefocusblock(see
Figure49).Initially,snugthesethreescrewsslightly,
thenbackthemoffapproximatelyone‐halfturntoallow
theguideblocktofloatrelativetothefocusblock.This
floatwillallowthewedgenutstomovetheslidingfocus
block,asthetensionscrewsaretightenedtoeliminate
thelateralplayintheslide.

Figure49–Reinstallscrewstosecuretheguideblock
AdjustforNoLateralPlayintheSlidingFocusBlock
Usea2.5mmAllenwrenchordrivertosnugthetwo
M3x16hex,socket‐headcapscrewstotightenthe
wedgenuts(andtherebymovetheguideblock)such


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page17of23 
thatthefocusblockslidesfreely,withoutstiffness,
binding,orlateralplaythroughoutthenormalrangeof
motion(seeFigure50).

Figure50–Adjustforfreemotionwithoutlateralplay
SecuretheGuideBlockinPosition
Usea2.5mmAllenwrenchordrivertotightenthethree
M3x12hex,socket‐headcapscrewstosecuretheguide
blockinpositiononthefocusblock(seeFigure51).

Figure51–Securetheguideblockinposition
TesttheFocusBlockforFreedomofMotion
Testthefreedomofmotionoftheslidingfocusblock,
makingsurethatthereisnosignificantstiffness,
binding,orlateralplayatanypointthroughoutthefull
rangeofmotionofthefocusblock(seeFigure52).If
necessary,loosenthethreeM3x12hex,socket‐head
capscrewssecuringtheguideblocktothefocusblock,
andthetwoM3x16hex,socket‐headcapscrewsthat
tensiontheguideblock,andreadjustpertheabove
procedureuntiltheresultingmotionoftheslidingfocus
blockissmooth,unrestricted,andwithoutlateralplay.

Figure52–Testtheslidingfocusblockforpropermotion
ReinstalltheTrimCover
CarefullypositiontheU‐shapedtrimcoverintoposition
onthearmcasting,aligningthefourholesinthetrim
coverwiththefourtappedholesinthecasting(see
Figure53).Becarefultoavoidbending,denting,or
scratchingthisfragilecover.

Figure53–Repositiontrimcoverontothearmcasting
UseasuitableJISscrewdrivertoreinstallfourM2x4JIS
screwstosecurethetrimcoverontothearmcasting
(seeFigure54).

Figure54–Reinstallscrewstosecurethetrimcover


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlock  Revision2Page18of23 
ReinstalltheArmontotheBase
Placethearmflatonitsbackontheworksurfacewith
thebottomfacingyou(seeFigure55).

Figure55–Placethearmflatontheworksurface
Holdthebaseofthestandinpositionsuchthatthefour
holesinthebasealignwiththefourtappedholesinthe
bottomsurfaceofthearmcasting(seeFigure56).

Figure56–Alignholesinthebasewithholesinthearm
Usea5mmAllenwrenchordrivertolooselyreinstall
fourM6x25hex,socket‐headcapscrewstoattachthe
armtothebaseofthestand(seeFigure57).

Figure57–Attachthebaseontothearmofthestand
Checkthealignmentofthearm(relativetothebase)
andadjustthepositioningasnecessaryforan
acceptablecosmeticappearanceattheinterface.
TightenthefourM6x25screwstosecurethearmtothe
base(seeFigure58).

Figure58–Securethearmontothebaseofthestand
ReinstalltheElectricalBase
Carefullylowertheassembledstandovertheelectrical
base,maintainingproperalignmentrelativetothe
electricalbase(topreventdamagetotheoptical
componentsinthebase)untilthestandseatsontothe
base.Iftheelectricalbasecontainsalight‐preset
control/switch(seeFigure5),besuretoreengagethis
intothenotchinthesideofthebase
3
beforeseating
thestandontotheelectricalbase.Whileholdingthe
electricalbaseinplacesothatitdoesnotshift,laythe
standontoitsbackorsideontheworksurface.Usea
4mm(or5/32”)Allenwrenchordrivertoreinstallfour
M5x12hex,socket‐headcapscrewsandassociated
washerstosecuretheelectricalbasetothestand(see
Figure59).Returntheassembledstandtoitsnormal
uprightposition.

Figure59–Reinstallscrewstosecuretheelectricalbase

3
Orreconnectthetwoelectricalconnectorstotheprintedcircuitboard.


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlockRevision2Page19of23
ContinuewiththeCoaxialFocusOverhaul
Theslidingfocusblockisnowreadyformanymore
yearsofservice.Atthispoint(ifapplicable),continue
withtheoverhaulofthecoaxialfocusmechanism,per
theappropriatepointintheCompleteTeardown,
Cleaning,andReassemblyoftheOlympusBH‐2Coaxial
FocusMechanismdocument.
OriginalOlympusDocumentation
AnearlyversionoftheOlympusBH2(BHS)repair
manual(seeFigure60)wasreferencedduringthe
preparationofthisdocument.AscannedPDFversion
ofthismanualisavailablefordownloadatvarious
microscope‐relatedhobbyistsitesontheinternetand
canbereadilylocatedbysearchingforthetitleinan
internetsearchengine,suchasGoogleorBing.

Figure60–TheOlympusBH2(BHS)repairmanual
HowtoContacttheAuthor
Pleasefeelfreetodirectanyquestionsorcomments
regardingthisdocument(orBH‐2microscopesin
general)totheauthor,atthefollowingemailaddress:
[email protected]


CompleteTeardown,Cleaning,andReassemblyoftheOlympusBH‐2SlidingFocusBlockRevision2Page20of23
Appendix1–HowtoInstallGuideRailsintheSlidingFocusBlockMechanism
PlacementofGuideRailsintheSideGrooves
Duringreassemblyoftheslidingfocusblock
mechanism,theguiderailsmustbeseatedintothe
insidecornersofthesidegroovesinthevarious
components(i.e.,theguideblock,thefocusblock,and
thearmcasting).Notethattheguiderailsare
manufacturedsuchthattheircross‐sectionalprofile
formsaright‐triangle,ascanbeseenintheendview
showninFigure61.Itiscriticalwheninstallingthese
railsthattheybeplacedsuchthatthetwosideswhich
formthe90°angleareplacedintothe90°inside
cornersofthesidegrooves,andthatthesidethatforms
thehypotenuseisfacingoutwards,providingasuitable
low‐frictionsurfaceforthecylindricalrollerstorollon.

Figure61–Correctorientationoftheguiderails
HoldingtheGuideRailsinPlaceforReassembly
Duringreassemblyoftheslidingfocusblock
mechanism,theguiderailswillneedtobeheldinplace
inthefocusblock,guideblock,andarmcastinguntilthe
slidemechanismhasbeenfullyreassembled.Theguide
railsdonotneedtobepermanentlystakedinplace,
sincethecylindricalrollerswillholdtheguiderailsin
placeoncetheslidemechanismhasbeenfully
reassembled.Accordingly,donotuseanyadhesiveto
securetheguiderailsinplace,otherwisetheadhesive
couldendupontheexposedbearingsurfacesofthe
guiderails,whichwouldinterferewiththecylindrical
rollersandpreventfreemotionoftheslidingfocus
block.Ratherthanutilizingadhesive,theguiderails
shouldinsteadbeheldinplaceduringreassemblyby
applyingheavygreasetobothendsofthesidegrooves
intheslideparts(intheinsidecorners)andthen
pressingtheguiderailsfirmlyintothisgreaseasthey
arereinstalledintoposition,makingsuretoproperly
orientthempertheprofileviewinFigure61.Afterthe
guiderailshavebeenplacedinpositionandpressed
intotheheavygrease,anyvisiblegreaseshouldbe
thoroughlyremovedbeforeproceedingwiththe
reassemblyoftheslidingfocusblockmechanism.Refer
tothefollowingdetailedprocedureforthesuggested
installationmethodfortheguiderails.
ReinstallingGuideRailsintotheGuideBlock
Thisproceduredescribesthesuggestedmethodtobe
usedtoinstalltheguiderailsintothevariousparts(i.e.,
theguideblock,thefocusblock,andthearmcasting)of
theslidingfocusblockmechanism.Theguideblockis
usedinthisspecificexample,butthesameprocedure
appliestothefocusblockandtothearmcastingas
well.
CleantheOldGreasefromtheSlideParts
Useasuitablesolvent(e.g.,acetone)tocleanalltraces
ofoilorgreasefromtheguiderails(seeFigure62)and
fromthesidegrooveoftheguideblock(seeFigure63).

Figure62–Thoroughlycleantheguiderails

Figure63–Thoroughlycleantheguideblock
ApplyHeavyGreasetoBothEndsoftheGuideBlock
Applyaheavygrease(item6ofAppendix2)tothe
insidecornersofbothendsofthesidegrooveinthe
guideblock(seeFigure64).