This procedure steps you through the installation and alignment of the ASI Z axis motor drive onto the Leitz Orthoplan microscope.
The ASI z-axis drive attaches and drives the fine focus shaft of the microscope. The drive assembly is secured to the microscope via a custom ASI backplate that mounts to the microscope utilizing the four pre-tapped holes that secured the original backplate. Precise alignment of the ASI drive onto the fine focus shaft of the microscope is accomplished through a triple axis sliding adjustment bar. Installing the ASI drive assembly involves six steps:
Note: the terms left and right refer to the sides of the microscope as viewed from the rear of the microscope and assemblies.
Remove the tungsten and UV lamp housings as outlined in the microscope’s manual. Turn the microscope so access to the rear of the unit can be easily obtained.
Remove the original backplate by removing the four 4x10mm slotted head screws that secure it to the microscope. Note the orientation of the UV illuminator flange that is attached to the original backplate. Use the 3mm allen wrench to remove the flange from the original backplate and install it onto the custom ASI backplate in the same orientation. Use the same 4x20mm screws that secured the flange to the original backplate. Note that the black threaded ring used to secure the flange to the original backplate will no longer be required as the ASI backplate is threaded. After securing the flange the ASI backplate may be installed on the microscope using the same 4x10mm slotted head screws that secured the original backplate.
a.) Remove the left fine focus knob by removing the 4x10mm slotted head screw that secures it to the fine focus shaft. A puller is required to pull the knob off of the fine focus shaft. Use the 5x25mm hex head screw that was shipped with the drive as the puller. Thread the 5x25mm hex head screw into the threads on the left fine focus knob, these threads are inside the knob where the 4×10 slotted screw was removed. Use the 4mm allen wrench to tighten the 5x25mm screw. As the screw is tightened the fine focus knob will come off of the shaft along with a spring. Check to insure that no washers have come off with the fine focus knob and spring. If a washer has come off check to insure that the small 2mm ball bearings are still seated in the race that is between the washer and the coarse focus knob. If any of the bearings have come out of the race simply install them back into the holes in the race and place the washer over the race to retain the bearings.
b.) Locate the ASI brass fine focus assembly and use the 3/32” allen wrench to loosen/remove the two ¼” 4/40 screws. After the screws are loose, pull up on the silver shaft while holding the larger brass piece to separate the two parts. Remove the spring from the original fine focus knob that was previously removed from the microscope in step a., and place the spring over the turned down side of the larger brass piece. Locate the 4x10mm screw that held the original fine focus knob on the microscope as it will be needed to secure the new assembly.
c.) Now, while pressing in on the right fine focus knob (which is located on the left when viewing the microscope from the rear) with your left hand, place the brass assembly and spring onto the microscope’s fine focus shaft and secure it in place with the 4x10mm screw. You must press in on the right fine focus knob to prevent the fine focus shaft from moving when installing the brass assembly. Once the 4x10mm screw is securely tightened, use the 0.05” allen wrench to tighten the set screw located on the side of the brass piece.
d.) After the large brass piece is secured to the microscope’s fine focus shaft, install the silver shaft and smaller brass piece that was taken off in step b., back onto the larger brass piece. Use the 4/40 screws and 3/32” allen wrench to make sure the pieces are secured tightly together.
Locate the motor assembly shipped with the ASI motor drive components. Use the 5/32” allen wrench to loosen, but do not remove, the x axis and the y, z adjustment screws located on the rear and the side of the motor drive. When these screws are loosened the motor drive should move freely about in the y and z axis. Check to insure that the clamp on the hollow end of the drive shaft which protrudes from the black encoder on the inside of the motor assembly is loose. If it is not loose, loosen it with the 7/64” allen wrench. The black o-ring will keep the clamp from falling off of the shaft. Facing the rear of the microscope, hold the motor assembly in your right hand and push in on the right fine focus knob with your left hand. Pushing in on the right fine focus knob with your left hand is to prevent the microscope’s fine focus shaft from sliding when you install the drive. Position the hollow end of the drive shaft (protruding from the black encoder) over the new ASI fine focus shaft on the right side of the microscope. Orient the motor assembly so that the two shafts are aligned, then push the motor drive assembly onto the microscope as far as it will go. Insure that you are pushing in on the right fine focus knob while pushing the motor drive onto the microscope. When the hollow ASI drive shaft is completely over the microscope’s fine focus shaft the ASI shaft should butt up against the ASI brass piece. While continuing to hold the motor assembly in your right hand, position the back of the motor drive with your left hand so that the four holes in it align with the four threaded holes on the ASI backplate that was installed in step number 2. Secure the drive to the backplate with the four 10/32 x ½” socket head screws. Insure that the shaft from the encoder is pressed against the brass piece and that the right fine focus knob is pressed in all of the way. Hold the right fine focus knob while moving the clamp that is on the encoder shaft in towards the brass piece as far as it will go. Use the 7/64” allen wrench to securely tighten the clamp
Carefully position the motor assembly along the x, y and z axis while rotating the right fine focus knob until minimum drag is felt. Tighten both the x axis and the y,z axis adjustment screws at the position where minimum drag is felt. These screws require the 5/32” allen wrench to tighten. After tightening the screws check to insure that minimum drag is felt for the complete 360 degree rotation of the fine focus knob. Repeat the alignment procedure if necessary.
Remove the two 4/40 screws from the edges of the drive assembly and the left fine focus knob that is on the ASI fine focus drive shaft. Locate the ASI cover. Place it in position over the motor drive assembly and secure it with the screws just removed. Place the left fine focus knob over the protruding end of the drive shaft and secure it in place with the set screw using a small, flat blade screwdriver.