Olympus BH2-5RE Installation instructions

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-5RE Modular Revolving Nosepiece Page 1 of 18
Revision 3
Complete Teardown, Cleaning, and
Reassembly of the Olympus BH2-5RE
Modular Revolving Nosepiece
Revision 3
Copyright © 2018, 2020, 2021 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 ([e-mail]). 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
June 25, 2018
2
Show worn mechanical detents
July 13, 2020
3
Common formatting, minor changes
May 19, 2021

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Table of Contents
Introduction ............................................................................................................................................................................5
Scope of this Document......................................................................................................................................................5
Tools Needed ..........................................................................................................................................................................5
A Few Words about JIS Screws ...........................................................................................................................................5
Supplies Needed .....................................................................................................................................................................5
Recommended Lubricant Types..........................................................................................................................................5
Recommended Solvents .....................................................................................................................................................6
Safety Considerations with Solvents...................................................................................................................................6
Solvent Compatibility with Parts and Finishes....................................................................................................................6
Before Starting the Overhaul..................................................................................................................................................6
Remove the Objectives from the Nosepiece ......................................................................................................................6
Label Parts for Identification and Reassembly....................................................................................................................6
Service the BH2-5RE Modular Nosepiece...............................................................................................................................6
Remove the Dovetail Slide..................................................................................................................................................6
Remove the Cover from the Turret Assembly ....................................................................................................................7
Remove Lock Ring for Pivot-Adjustment Screw..................................................................................................................7
Remove the Pivot-Adjustment Screw.................................................................................................................................8
Remove the Center-Pivot Bearing Ball................................................................................................................................9
Remove the Mechanical Detent Stop .................................................................................................................................9
Remove the Knurled-Rubber Grip Ring...............................................................................................................................9
Remove the Threaded Retaining Ring ..............................................................................................................................10
Remove the Perimeter Bearing Balls ................................................................................................................................10
Remove the Stationary Base from the Turret...................................................................................................................10
Clean Grease from the Various Components ...................................................................................................................11
Reinstall Stationary Base into Revolving Turret................................................................................................................11
Apply Ring of Grease for the Perimeter Balls ...................................................................................................................11
Reinstall the Perimeter Bearing Balls................................................................................................................................11
Reinstall the Threaded Retaining Ring..............................................................................................................................11
Apply Grease to the Center-Pivot Bore.............................................................................................................................12
Reinstall the Center-Pivot Bearing Ball.............................................................................................................................12
Apply Grease to Top of the Center-Pivot Ball...................................................................................................................12
Reinstall the Pivot-Adjustment Screw ..............................................................................................................................12
Reinstall the Slotted Lock Ring..........................................................................................................................................13
Verify the Feel of the Revolving Nosepiece......................................................................................................................13
Clean Off Any Visible Grease.............................................................................................................................................13
Reinstall the Mechanical Detent Stop...............................................................................................................................13
Apply Grease to the Mechanical Detents .........................................................................................................................14
Reinstall the Protective Cover...........................................................................................................................................14
Reinstall the Dovetail Slide ...............................................................................................................................................14
Reinstall the Knurled-Rubber Grip Ring............................................................................................................................15
Ready for Service ..................................................................................................................................................................15
Requirements for Periodic Maintenance..............................................................................................................................15
Problems with the Turret Assembly .....................................................................................................................................16
Original Olympus Documentation ........................................................................................................................................16
Olympus Research Microscopes Series BH2 (BHS) Repair Manual...................................................................................16
Olympus Research Microscope BH2 Repair Manual.........................................................................................................16
How to Contact the Author...................................................................................................................................................16
Appendix 1 ............................................................................................................................................................................17
Inspecting the Revolving Turret for Wear of the Mechanical Detents.............................................................................17
Appendix 2 ............................................................................................................................................................................18

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Sources for Replacement Parts, Tools, and Supplies Referenced in this Document........................................................18
Table of Figures
Figure 1 –A typical JIS Screw ..................................................................................................................................................5
Figure 2 –The BH2-5RE modular revolving nosepiece...........................................................................................................6
Figure 3 –Basic components of the BH2-5RE.........................................................................................................................6
Figure 4 –Remove four screws securing the dovetail slide....................................................................................................7
Figure 5 –Remove the loose dovetail slide ............................................................................................................................ 7
Figure 6 –Remove screws securing the cover in place ..........................................................................................................7
Figure 7 –Remove the protective cover.................................................................................................................................7
Figure 8 –The turret assembly (without cover) .....................................................................................................................7
Figure 9 –Screwdriver modified to remove slotted lock ring ................................................................................................8
Figure 10 –Insert screwdriver into bores to lock turret.........................................................................................................8
Figure 11 –Loosen the slotted lock ring.................................................................................................................................8
Figure 12 –Remove the slotted lock ring ...............................................................................................................................8
Figure 13 –Remove the pivot-adjustment screw...................................................................................................................9
Figure 14 –Remove the center-pivot bearing ball ................................................................................................................. 9
Figure 15 –Remove the screws securing the detent stop......................................................................................................9
Figure 16 –Remove the loose mechanical detent stop..........................................................................................................9
Figure 17 –Remove the knurled-rubber grip ring ..................................................................................................................9
Figure 18 –Components of the turret assembly..................................................................................................................10
Figure 19 –Loosen the threaded retaining ring ...................................................................................................................10
Figure 20 –Remove the threaded retaining ring..................................................................................................................10
Figure 21 –Remove the perimeter bearing balls .................................................................................................................10
Figure 22 –Lift and remove the stationary base ..................................................................................................................10
Figure 23 –Reinstall stationary base into revolving turret...................................................................................................11
Figure 24 –Apply ring of fresh grease for the bearing balls.................................................................................................11
Figure 25 –Place the bearing balls into the ring of grease...................................................................................................11
Figure 26 –Engage the threaded retaining ring ...................................................................................................................11
Figure 27 –Tighten the threaded retaining ring...................................................................................................................11
Figure 28 –Remove any grease squeeze-out .......................................................................................................................12
Figure 29 –Apply grease to the center-pivot bore...............................................................................................................12
Figure 30 –Place bearing ball into the center-pivot bore ....................................................................................................12
Figure 31 –Apply grease to the top of the bearing ball .......................................................................................................12
Figure 32 –Reinstall the pivot-adjustment screw ................................................................................................................12
Figure 33 –Reinstall the slotted lock ring.............................................................................................................................13
Figure 34 –Tighten the slotted lock ring ..............................................................................................................................13
Figure 35 –Place the mechanical detent stop in position....................................................................................................13
Figure 36 –Secure the detent stop with two screws ...........................................................................................................13
Figure 37 –Apply grease to the five detent notches............................................................................................................14
Figure 38 –Place cover in position on the turret assembly..................................................................................................14
Figure 39 –Secure protective cover using three screws ......................................................................................................14
Figure 40 –Position dovetail slide onto stationary base......................................................................................................14
Figure 41 –Secure dovetail slide onto stationary base........................................................................................................14
Figure 42 –Apply black adhesive to revolving turret ...........................................................................................................15
Figure 43 –Reinstall the knurled-rubber grip ring................................................................................................................15
Figure 44 –Remove any adhesive squeeze-out....................................................................................................................15

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Figure 45 –BH2-5RE ready to be put back into service........................................................................................................15
Figure 46 - Revolving turret with severely worn mechanical detents..................................................................................17
Figure 47 –Close-up view of a worn mechanical detent notch............................................................................................17

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Introduction
The microscopes in the Olympus BH-2 line 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 they
are 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 issue that might be encountered when purchasing
either the BHS or BHT version of these microscopes is
that the grease in the BH2-5RE modular revolving
nosepiece assembly may be dried and gummy, resulting
in a stiff or gritty feel of the revolving nosepiece.
Another issue that may be encountered is with the
mechanical detents in the revolving nosepiece. After
many years of hard service, especially if the nosepiece
assembly has not been periodically lubricated
throughout its life, one or more of the detent stops may
be worn to the point where the detents are sloppy, and
the affected objectives do not maintain proper radial
indexing. At best, this is annoying to the operator, and
at worst can render the revolving nosepiece unusable.
This document describes the complete teardown,
cleaning, lubrication, and reassembly of the BH2-5RE
(five-position) modular revolving nosepiece assembly as
used on a BHS or BHT microscope stand. Completion of
this maintenance procedure should restore the proper
feel to the nosepiece turret. Additionally, this
maintenance should reduce further wear of the
mechanical detent stops. Note that if the detents stops
are already excessively worn, there is no repair for this
other than the replacement of the revolving turret.
Scope of this Document
The procedures detailed in this document directly apply
to the BH2-5RE (five-position) revolving modular
nosepiece assembly used on the Olympus BHS, BHSP,
BHT, and BHTP microscope stands. This procedure is
also applicable the BH2-6RE (six-position) modular
revolving nosepiece assembly, due to its similarity with
the five-position nosepiece, although a separate
document exists in this series detailing the BH2-6RE.
Note that the original Olympus service literature did not
address the teardown and repair of the various
revolving nosepiece assemblies used on BH-2 stands, as
these were field-replaceable assemblies that were
considered unserviceable by Olympus.
Tools Needed
The following tools will be needed to complete the
teardown, cleaning, lubrication, and reassembly of the
BH2-5RE modular revolving nosepiece assembly.
•Center punch or nailset tool
•Electric heat gun (item T1 of Appendix 1)
•Lens-spanner tool (item T3 of Appendix 1)
•Screwdriver set, JIS (item T2 of Appendix 1)
A Few Words about JIS Screws
Screws with JIS heads are frequently found in much of
the older 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 driver
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 –A typical JIS Screw
Supplies Needed
The following supplies will be needed to complete the
teardown, cleaning, lubrication, and reassembly of the
BH2-5RE modular revolving nosepiece assembly.
•Cleaning solvent (see recommendations below)
•Lubricant (see recommendations below)
•Adhesive, black (item S1 of Appendix 1)
Recommended Lubricant Types
Plastilube® Brake Grease or Mobilgrease28® grease
(item S2 of Appendix 1) are recommended for use in
the BH2-5RE modular revolving nosepiece assembly.
Both Plastilube® Brake Grease and Mobilgrease28® are
medium-consistency greases which will remain stable
and serviceable for many years to come.

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Recommended Solvents
Some sort of solvent will be needed to clean the old
grease from the components of the BH2-5RE modular
revolving nosepiece assembly. Solvents that can be
used are acetone, diethyl ether, heptane, hexane,
mineral spirits, turpentine, and xylene. Mineral spirits
works well with both Plastilube® and Mobilgrease28®.
Safety Considerations with Solvents
Regardless of which solvent is chosen, make sure that
adequate ventilation is present during the cleaning
process, and that any necessary personal protective
equipment is utilized to minimize exposure. Consult the
safety data sheet (SDS or MSDS) 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 or will dissolve or damage plastic parts
(isopropyl alcohol or 409 Cleaner may be safely used to
clean most painted surfaces). Do not allow untested
solvents to contact any plastic parts or 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.
Before Starting the Overhaul
Remove the Objectives from the Nosepiece
Before beginning the teardown of the BH2-5RE modular
revolving nosepiece assembly, remove the nosepiece
assembly from the microscope stand and remove all of
the objectives (if present) from the revolving turret.
Store the objectives someplace where they will be
protected from physical damage, dust, and debris.
Label Parts for Identification and Reassembly
During the teardown of the BH2-5RE modular revolving
nosepiece assembly, be sure to bag and tag the various
parts as they are removed, to prevent their loss and to
facilitate their proper identification during the
reassembly process.
Service the BH2-5RE Modular Nosepiece
Figure 2 shows the five-position BH2-5RE modular
revolving nosepiece assembly used on the Olympus BHS
and BHT microscope stands.
Figure 2 –The BH2-5RE modular revolving nosepiece
The BH2-5RE modular revolving nosepiece assembly
consists of a five-position turret assembly, which is
made up of an inner stationary base, an outer revolving
turret, miscellaneous parts and a protective cover.
Attached to the turret assembly is a machined dovetail
slide, for mounting the BH2-5RE onto the BHS/BHT
stand (see Figure 3).
Figure 3 –Basic components of the BH2-5RE
The procedure to disassemble, clean/re-grease, and
reassemble the BH2-5RE modular revolving nosepiece
assembly is detailed in the following sections.
Remove the Dovetail Slide
The dovetail slide attaches to the stationary base of the
turret assembly via four M2.6X5 pan-head screws. Use
a suitable JIS screwdriver to remove these four M2.6X5
screws (see Figure 4) and then remove the loose
dovetail slide from the stationary base (see Figure 5).

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Figure 4 –Remove four screws securing the dovetail slide
Figure 5 –Remove the loose dovetail slide
Remove the Cover from the Turret Assembly
Use a suitable JIS screwdriver to remove the three
M2X3 countersink screws securing the protective cover
onto the stationary base (see Figure 6) and remove the
protective cover (see Figure 7).
Figure 6 –Remove screws securing the cover in place
Figure 7 –Remove the protective cover
Figure 8 –The turret assembly (without cover)
Remove Lock Ring for Pivot-Adjustment Screw
The slotted lock ring for the pivot-adjustment screw
(see Figure 8) can be difficult to remove unless the
proper tool is used. Do not attempt to remove the
slotted lock ring from the pivot-adjustment screw
unless you have access to such a tool, since the slot in
the lock ring will likely be damaged if you use an
improper tool, making removal of the lock ring much
more difficult
1
.
A suitable tool for this task can be easily made by filing
or grinding a relief notch for the pivot-adjustment screw
in the center of the blade of a large slotted screwdriver,
as shown in Figure 9.Note that if you decide to make
such a tool, be sure that the tip of the screwdriver you
select has a blade width matching the outer diameter of
the slotted lock ring, and that the thickness of the blade
is such that it will seat fully into the slot of the slotted
lock ring.
1
Don’t even think about using a pair of needle-nose pliers to loosen
the slotted lock ring. It will end badly if you do this. Don’t ask me
how I know this.

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Figure 9 –Screwdriver modified to remove slotted lock ring
Prevent the Revolving Turret from Spinning
Before attempting to loosen the slotted lock ring, the
revolving turret must first be locked in position relative
to the stationary base, in order to allow for sufficient
torque to be applied to the slotted lock ring to loosen
and remove it. To lock the position of the revolving
turret, first spin the revolving turret until the bore in the
stationary base aligns with one of the five threaded
objective bores in the revolving turret. While holding
the turret such that these two bores remain aligned,
insert a small screwdriver handle of the appropriate size
into the two bores (see Figure 10). This will prevent the
revolving turret from moving relative to the stationary
base when torque is applied to loosen the slotted lock
ring. The handle of the screwdriver should safely
prevent the turret from spinning, without causing any
damage to the fragile brass threads in the revolving
turret.
Figure 10 –Insert screwdriver into bores to lock turret
Loosen and Remove the Slotted Lock Ring
Hold the turret assembly by grasping the knurled-
rubber grip ring on the outer perimeter of the revolving
turret and use the slotted screwdriver with the notched
tip (see Figure 9)to loosen the slotted lock ring securing
the pivot-adjustment screw to the stationary base (see
Figure 11).
Figure 11 –Loosen the slotted lock ring
Once the slotted lock ring has been loosened, remove
the screwdriver handle from the bores in the revolving
turret and the stationary base (which is locking the
revolving turret to the stationary base) to get it out of
the way. Unscrew and remove the slotted lock ring
from the pivot-adjustment screw (see Figure 12).
Figure 12 –Remove the slotted lock ring
Remove the Pivot-Adjustment Screw
With the slotted lock ring removed, use a suitable
slotted screwdriver to unscrew and remove the pivot-
adjustment screw from the center bore of the
stationary base (see Figure 13). Note that there is a ¼”
bearing ball in the center bore of the stationary base,
beneath the pivot-adjustment screw. Do not allow this
bearing ball to fall out or it may become lost.

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Figure 13 –Remove the pivot-adjustment screw
Remove the Center-Pivot Bearing Ball
Use a tweezers to remove the ¼” bearing ball from the
center bore in the stationary base (see Figure 14).
Figure 14 –Remove the center-pivot bearing ball
Remove the Mechanical Detent Stop
The next step is to remove the mechanical detent stop
from the stationary base of the turret assembly. Use a
suitable JIS screwdriver to remove the two M2X4 pan-
head screws securing this stop to the stationary base
(see Figure 15). These screws are staked in place with
adhesive and can be surprisingly stubborn to remove, so
be sure to use the proper JIS screwdriver to prevent
damaging the screw heads. It might also be helpful to
heat the screws with a heat gun before loosening them,
but do not melt the black knurled-rubber grip ring in the
process.
Figure 15 –Remove the screws securing the detent stop
Remove the loose mechanical detent stop from the
stationary base (see Figure 16).
Figure 16 –Remove the loose mechanical detent stop
Remove the Knurled-Rubber Grip Ring
Carefully remove the black knurled-rubber grip ring
from the outer perimeter of the revolving turret (see
Figure 17), being careful not to stretch or damage it in
the process. This ring is held onto the turret with a few
spots of adhesive, so proceed carefully here.
Figure 17 –Remove the knurled-rubber grip ring

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Remove the Threaded Retaining Ring
The stationary base is held inside the recess of the
revolving turret by the threaded retaining ring (see
Figure 18).
Figure 18 –Components of the turret assembly
Place the turret assembly into a suitable work vise and
use a heat gun to thoroughly heat the turret assembly,
to soften the internal grease. Then use a center punch
or nailset tool to loosen the threaded retaining ring by
placing the tip of the tool into one of the four tooling
holes in the threaded retaining ring (see Figure 18) and
driving the threaded retaining ring counter-clockwise by
carefully tapping the tool with a small hammer or mallet
(see Figure 19). Be careful and do not accidentally put
the center punch or nailset tool into one of the five
detent notches in the revolving turret (instead of into
one of the four tooling holes in the threaded retaining
ring), or the revolving turret will be irreparably
damaged when the punch is struck by the mallet.
Figure 19 –Loosen the threaded retaining ring
Continue loosening the threaded retaining ring and
remove it, being careful that the perimeter bearing balls
beneath the threaded retaining ring do not fall out and
become lost in the process (see Figure 20).
Figure 20 –Remove the threaded retaining ring
Remove the Perimeter Bearing Balls
Carefully remove the 3/32” bearing balls (there are 80
of them) from the perimeter of the stationary base. A
small magnet can come in handy here (see Figure 21).
Figure 21 –Remove the perimeter bearing balls
Remove the Stationary Base from the Turret
Once the perimeter bearing balls have been removed,
lift the stationary base free of the recess in the
revolving turret and remove it (see Figure 22).
Figure 22 –Lift and remove the stationary base

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Clean Grease from the Various Components
Use a suitable solvent (e.g., acetone) to thoroughly
clean all the old grease from the stationary base,
revolving turret, threaded retaining ring, perimeter
bearing balls, center-pivot ball, mechanical detent stop,
pivot-adjustment screw, and the slotted lock ring, in
preparation for reassembly.
Reinstall Stationary Base into Revolving Turret
Hold the stationary base such that the center pivot is
facing downwards, and lower the stationary base into
the recess of the revolving turret (see Figure 23).
Figure 23 –Reinstall stationary base into revolving turret
Apply Ring of Grease for the Perimeter Balls
The next step is to apply grease into the ring in which
the perimeter bearing balls will be placed. Carefully
apply a ring of grease (item S2 of Appendix 1) into the
channel formed between the outer perimeter of the
stationary base and the inner perimeter of the revolving
turret (see Figure 24). Do not apply too much grease
here, to minimize the squeeze-out that will occur when
the threaded retaining ring is reinstalled to hold the
stationary base into the recess of the revolving turret.
Figure 24 –Apply ring of fresh grease for the bearing balls
Reinstall the Perimeter Bearing Balls
Use tweezers to carefully set the 3/32” bearing balls
(there are 80 of them) into the grease ring (see Figure
25), placing the bearing balls as close together as
possible as you proceed.
Figure 25 –Place the bearing balls into the ring of grease
Reinstall the Threaded Retaining Ring
Carefully engage the threads of the threaded retaining
ring with the threads in the revolving turret (see Figure
26).
Figure 26 –Engage the threaded retaining ring
Use a suitable lens spanner tool (item T3 of Appendix 1)
in a pair of opposing tooling holes to tighten the
threaded retaining ring
2
(see Figure 27).
Figure 27 –Tighten the threaded retaining ring
2
Or use a center punch or nailset tool to snug the threaded retaining ring by placing the
tip of the tool into one of the four tooling holes and lightly tapping the tool with a small
hammer or mallet to drive the threaded retaining ring clockwise.

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While holding the stationary base in one hand, quickly
spin the revolving turret multiple times in both
directions with the other hand, to drive out any excess
grease from beneath the threaded retaining ring. Use
dry cotton swabs to remove any grease squeeze-out
(see Figure 28). Do not use a solvent here, otherwise
the solvent may run into the revolving turret
mechanism and foul the grease within.
Figure 28 –Remove any grease squeeze-out
Apply Grease to the Center-Pivot Bore
Apply a small amount of grease (item S2 of Appendix 1)
into the center-pivot bore of the stationary base for the
¼” bearing ball (see Figure 29).
Figure 29 –Apply grease to the center-pivot bore
Reinstall the Center-Pivot Bearing Ball
Now that the center-pivot bore has been greased,
reinstall the ¼” bearing ball into the freshly greased
center-pivot bore. The grease will hold the center-pivot
bearing ball in the proper position during subsequent
reinstallation of the pivot-adjustment screw (see Figure
30).
Figure 30 –Place bearing ball into the center-pivot bore
Apply Grease to Top of the Center-Pivot Ball
Apply a small amount of grease (item S2 of Appendix 1)
onto the top of the ¼” bearing ball in the center-pivot
bore (see Figure 31).
Figure 31 –Apply grease to the top of the bearing ball
Reinstall the Pivot-Adjustment Screw
Use a suitable slotted screwdriver to reinstall the pivot-
adjustment screw into the threaded bore in the center
of the stationary base (see Figure 32). Carefully snug
the adjustment screw just to the point where a slight bit
of resistance is felt. Test the feel of the revolving turret.
If the motion feels rough, back the screw off a bit until it
feels smooth. Leave the screw in this position.
Figure 32 –Reinstall the pivot-adjustment screw

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Reinstall the Slotted Lock Ring
Carefully engage the threads of the slotted lock ring
onto the pivot-adjustment screw (see Figure 33).
Figure 33 –Reinstall the slotted lock ring
Spin the revolving turret until one of the five threaded
objective bores in the revolving turret aligns with the
bore in the stationary base. Insert a suitably sized
screwdriver handle into these bores to lock the
revolving turret to the stationary base. Use a suitable
tool (see Figure 9) to snug the slotted lock ring down to
lock the pivot-adjustment screw in place (see Figure
34). Do not allow the pivot-adjustment screw to rotate
while tightening the slotted lock ring.
Figure 34 –Tighten the slotted lock ring
Verify the Feel of the Revolving Nosepiece
Hold the turret assembly by gripping the stationary base
in one hand and spin the revolving turret with the other
hand. The motion of the turret should not feel gritty,
erratic, or excessively stiff. If it does, loosen the slotted
lock ring, readjust the pivot-adjustment screw, and
retighten the slotted lock ring (as described above) until
the turret motion feels acceptable.
Clean Off Any Visible Grease
Use a suitable solvent (e.g., mineral spirits) and a clean
rag or tissue to thoroughly clean any visible grease from
the exterior of the turret assembly. Be careful while
removing the excess grease, to prevent any of the
solvent from dripping into the revolving turret
mechanism and fouling the grease within.
Reinstall the Mechanical Detent Stop
Place the mechanical detent stop in position on the
stationary base, aligning the two holes in the
mechanical detent stop with the two tapped holes in
the stationary base (see Figure 35). Make sure the stop
ball on the detent stop is facing downwards.
Figure 35 –Place the mechanical detent stop in position
Use a suitable JIS screwdriver to reinstall two M2X4
pan-head screws to secure the mechanical detent stop
in place on the stationary base (see Figure 36).
Figure 36 –Secure the detent stop with two screws

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Apply Grease to the Mechanical Detents
Apply fresh grease (item S2 of Appendix 1) to the five
mechanical detent notches in the revolving turret (see
Figure 37). Be careful that you do not get grease
anywhere else.
Figure 37 –Apply grease to the five detent notches
Reinstall the Protective Cover
Place the protective cover into position on the back side
of the turret assembly, lining up the three holes in the
protective cover with the three tapped holes in the
stationary base (see Figure 38).
Figure 38 –Place cover in position on the turret assembly
Use a suitable JIS screwdriver to reinstall three M2X3
countersink screws to secure the protective cover onto
the stationary base (see Figure 39).
Figure 39 –Secure protective cover using three screws
Reinstall the Dovetail Slide
Place the dovetail slide into position on the back side of
the turret assembly, lining up the four holes in the
dovetail slide with the four corresponding tapped holes
in the stationary base (see Figure 40). Be sure to orient
the dovetail slide such that the relief notch (see inset of
Figure 40) is facing downwards and towards the slotted
lock ring on the pivot-adjustment screw.
Figure 40 –Position dovetail slide onto stationary base
Use a suitable JIS screwdriver to reinstall four M2.6X5
pan-head screws to secure the dovetail slide onto the
stationary base of the turret assembly (see Figure 41).
Figure 41 –Secure dovetail slide onto stationary base

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-5RE Modular Revolving Nosepiece Page 15 of 18
Revision 3
Reinstall the Knurled-Rubber Grip Ring
The final assembly step for the turret assembly is to
reinstall the black knurled-rubber grip ring around the
outer perimeter of the revolving turret and secure it in
place with a suitable color-matching adhesive.
Black E6000 is a good choice of adhesive here, since it
will bond well with the metal of the revolving turret as
well as to the black knurled-rubber grip ring.
Additionally, any of the inevitable squeeze-out that is
not completely removed will not be visible. Apply two
dabs of the black adhesive (item S1 of Appendix 1) onto
the outer perimeter of the revolving turret, spaced
approximately 180° apart (see Figure 42).
Figure 42 –Apply black adhesive to revolving turret
Carefully reinstall the knurled-rubber grip ring onto the
outer perimeter of the revolving turret, making sure to
not stretch or damage the grip ring in the process (see
Figure 43).
Figure 43 –Reinstall the knurled-rubber grip ring
Use dry cotton swabs lightly dampened with isopropyl
alcohol to thoroughly remove any adhesive squeeze-
out (see Figure 44).
Figure 44 –Remove any adhesive squeeze-out
Ready for Service
The newly reconditioned BH2-5RE modular revolving
nosepiece assembly is now ready to provide many more
years of service (see Figure 45).
Figure 45 –BH2-5RE ready to be put back into service
Requirements for Periodic Maintenance
Periodic cleaning and application of fresh grease to the
mechanical detent notches in the stationary base is
necessary to minimize wear of the mechanical detents,
thereby maximizing the useful service life of the
BH2-5RE. This can be easily accomplished by simply
removing the protective cover, cleaning and re-greasing
the detent notches, and then reinstalling the protective
cover per the procedures detailed in this document.
The dovetail slide does not need to be removed to
perform this periodic maintenance. If the equipment
sees heavy usage, this service should be performed on a
six-month interval
3
.
3
Field experience has shown that even heavily used scopes (such as those
used in hospitals and clinical lab settings), when lubricated on a six-month
interval, can be expected to provide many years of trouble-free service.

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-5RE Modular Revolving Nosepiece Page 16 of 18
Revision 3
Problems with the Turret Assembly
A few problems with the turret assembly can
sometimes be found in the reassembled nosepiece. The
first will be seen if one or more of the mechanical
detents are excessively worn. This will cause radial float
of the revolving turret in one or more of the objective
positions, and these objectives will have trouble
returning to and maintaining their proper index
position. This can make it difficult to utilize some
illumination types, such as phase contrast, since the
phase annuli will not be able to hold an acceptable
alignment due to variations in objective indexing.
The other problem that may be seen is caused by
overall float of the revolving turret, relative to the
center point of the stationary base. If there is excess
play in the center-pivot ball, such that the turret is not
held in the exact center point, the whole turret may
move slightly, resulting in poor objective centering and
all that that entails. This problem may be encountered
if the threaded retaining ring has not been properly
snugged down, or if the center pivot-adjustment screw
has not been properly adjusted to remove the play in
the center-pivot mechanism.
Original Olympus Documentation
Scanned versions of the following PDF service manuals
are available for download at various microscope-
related hobbyist sites on the internet. These can also
be found by searching for the titles in an internet search
engine, such as Google.
Olympus Research Microscopes Series BH2 (BHS) Repair Manual
Olympus Research Microscope BH2 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 email address included on
the cover page of this document.

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-5RE Modular Revolving Nosepiece Page 17 of 18
Revision 3
Appendix 1
Inspecting the Revolving Turret for Wear of the Mechanical Detents
The photos below show the revolving turret from a BH2-5RE modular revolving nosepiece which has severely worn
mechanical detents, as a result of extensive use and a poor service history. The revolving turret is made of brass (a soft
metal), with a hard, corrosion/wear-resistant layer of dull, silver-colored plating on the exposed surface. When the hard
plating in the area of the mechanical detents begin to wear away, as a result of severe use without routine cleaning and
re-greasing of the detents, the underlying brass will then be exposed. This exposed brass will then wear very quickly
with continued usage, soon rendering the BH2-5RE unusable. Figure 46 shows an example of a revolving turret with
severe wear. Exposed brass is visible in the areas of the mechanical detents. Figure 47 shows a close-up of one of the
mechanical detents, where the wear can clearly be seen.
Figure 46 - Revolving turret with severely worn mechanical detents
Figure 47 –Close-up view of a worn mechanical detent notch

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-5RE Modular Revolving Nosepiece Page 18 of 18
Revision 3
Appendix 2
Sources for Replacement Parts, Tools, and Supplies Referenced in this Document
Table 1, Table 2, and Table 3 lists specific information for the various tools, supplies, and parts discussed in this
document. The pricing and availability listed below is accurate as-of May 2021 but is subject to change without notice.
Item
Description
Manufacturer
Manufacturer Model #
Vendor
Vendor #
Price
T1
Heat gun, electric, 1500W
Drill Master
---
Harbor Freight
96289
$9.47
T2
Screwdriver set, JIS, 4 pieces
Hozan
JIS-4
Amazon
---
$19.00
T3
Lens spanner tool, pointed
various
---
Amazon
---
$18.99
Table 1 –Tools referenced in this document
Item
Description
Manufacturer
Manufacturer Model #
Vendor
Vendor #
Price
S1
E6000 adhesive, black, 2 oz.
E6000
---
Amazon
---
$8.22
S2
Plastilube® Brake Grease, 75 cc
Plastilube®
ATE70015
Amazon
---
$10.88
Plastilube® Brake Grease, 75 cc
Plastilube®
ATE70015
Autohausaz
1161688
$8.35
Mobilgrease28 grease, 13.4 oz.
Mobil
Mobilgrease28
Amazon
---
$22.75
Table 2 –Supplies referenced in this document
Item
Description
Manufacturer
Manufacturer Model #
Vendor
Vendor #
Price
P1
Bearing balls, chrome steel, 3/32” G25, 100-count
various
---
Amazon
---
$4.55
P2
Bearing balls, chrome steel, 1/4”, G25, 25-count
various
---
Amazon
---
$5.50
Table 3 –Parts referenced in this document
Table 4 lists the contact information for the vendors referenced in Table 1, Table 2, and Table 3.
Vendor
URL
Local Phone
Toll Free
Fax
email
Amazon
www.amazon.com
---
---
---
---
Autohausaz
www.autohasuaz.com
---
---
---
[email protected]m
Harbor Freight Tools
www.harborfreight.com
---
1-800-423-2567
---
---
Table 4 –Vendor Listing