Table of Contents

Olympus IX71 Microscope Z-Axis Motor Drive Installation

This procedure steps you through the installation and alignment of the ASI’s IX71 Z-axis motor drive onto the Olympus IX71 microscope.

NOTE: On January 2007 Olympus changed the size of the threaded end of their fine focus shaft from 3 mm to 4 mm. Microscopes with serial numbers '7Axxxxxx' and newer, and all 8-digit versions, identify the 4 mm version. The threaded shaft diameter can also be directly measured after the left-hand fine-focus knob has been removed. This installation manual applies to both versions.

Typical diameter of threaded end of Olympus 4 mm fine focus shaft
ASI offers Z-Drives with drive shafts for both 3 mm and 4 mm versions
Threaded diameter of ASI’s 3 mm drive shaft
Threaded diameter of ASI’s 4 mm drive shaft


The following tools are required for this procedure:

The procedure has three parts:

  1. Removing the left fine focus knob
  2. Installing flexible coupling
  3. Installing and aligning the motor drive assembly and baseplate.
  4. Installing the cover.

Note: the terms ‘left’ and ‘right’ refer to the sides of the microscope as viewed from the front of the microscope.

Part 1: Removing the Left Fine Focus Knob

Use Allen wrench to remove screw that secures the outer focus knob.
Unscrew inner left fine focus knob while holding the right fine focus knob.
Spring washer on brass shaft can be left in place.


Part-2: Installing Flexible Coupling and Baseplate

Slide flexible coupler over threaded end of fine focus shaft while holding right hand knob in place.
Tighten clamp on flexible coupler while holding right hand knob in place.


Slide flexible coupler over the threaded end of the left fine focus shaft while holding the right fine focus knob in place, and tighten clamp with a 2 mm or 5/64 inch Allen wrench. Ensure that it is pressed all the way against the brass part of the left microscope knob without pushing the right focus knob out on the other side. Check for any play in the focus shaft by pushing and pulling the focus knob as shown on the left – no movement should be evident.  

Part-3: Installing and Aligning the Z-axis Motor Drive

Remove motor drive assembly from base plate (if attached) by using the 7/64 inch Allen wrench to remove the horizontal adjustment screw.
Use the 7/64 inch Allen wrench to loosen the two vertical adjustment screws.
Slide base plate under microscope and center beneath focus assembly.
Leave base plate clamp loose at this time.
Slide the drive shaft into the flexible coupler.
Coupler accepts about 4 mm of the drive shaft.
Reinstall the horizontal adjustment screw and tighten loosely for later adjustment.
Tighten the baseplate clamp snugly.
Tighten the flexible coupler’s clamp onto the drive shaft.

Note: The flexible coupler clamp must be securely tightened or the drive may slip.

Tighten the vertical adjustment screws after alignment.
Tighten the horizontal adjustment screws after alignment.

Note: there should be no point throughout the 360º rotation of the fine focus knob where an increase in drag is felt. If drag is felt, repeat the above steps.

Part 4: Installing the Motor Drive Cover Plate and Fine Focus Knob

Install cover with screws as shown
Screw on small focus knob as shown.
  1. Locate the motor drive cover. Position it over the motor drive assembly and secure in place as shown, using the two small 4/40 screws and 1/16” Allen wrench provided.
  2. Screw the microscope fine focus knob onto the shaft extension, as shown, while holding the right fine focus knob. Check to ensure the left fine focus knob does not rub against the cover. If it does, loosen and move the cover and then re-secure the cover in place after knob rotates freely.
  3. Reinstall the large outer knob that was removed in Part One. Replace the rubber boot, if present.
After screwing on small knob, attach the large knob.
Drive and cover installed on the Olympus IX71.

This completes the procedure for installing the ASI Z-axis motor drive onto the Olympus IX71.