Stage Adapter Plate

With the riser block finished, the Leitz Universal Stage has to be attached to the Olympus BX51-Pol stage.  On a Leitz polarizing microscope, there are already two drilled and tapped holes in the pol-stage to accommodate the Universal Stage.  These holes are 85 mm apart, and are tapped M3.5 x 0.60, to take the two special U-stage mounting screws that accompany the Universal Stage.  [Note:  for those not familiar with screw thread designation, the “M” means that the dimensions are in metric units; the “3.5” means that the thread diameter is 3.5 mm; and the “0.60” refers to the pitch of the thread, i.e. the number of threads per millimeter.]  There are no matching tapped holes 85 mm apart in the Olympus stage; there are, however, several other tapped holes in the Olympus stage toward the perimeter that could serve to attach a metal plate, to which the Leitz U-stage could be mounted.  Accordingly, measurements were taken.  Figure 5 (Download PDF) is an engineering drawing of the proposed adapter plate, eventually to be black anodized.  The adapter plate can be made from 1/16” thick or 3/32” thick aluminum sheet.  If homemade, the sheet aluminum can be bought at a hardware store and the necessary piece can be fabricated using a circle-cutter chucked in a drill press.  [A circle-cutter is like a pilot drill with an outboard arm that carries on its end a cutting tool that can be adjusted for distance along the arm.]

click image to enlarge (100K) Figure 5

In use, the universal stage requires that the central disc insert in the microscope stage be removed; there is a correspondingly large opening in the base of the U-stage.  A 5.83” diameter disc is cut out of the aluminum sheet, and a 2.84” diameter piece is cut out of the center of that.  Two ¼” holes are drilled 120° apart where specified in the engineering drawing; these will allow room for attaching, centering, and adjusting the adapter plate to the Olympus stage.  Then two holes are drilled 85 mm apart where indicated in the engineering drawing.  These holes should be made with a 2.9 mm drill, which is the size needed to tap the two holes M3.5 x 0.60.  That completes the adapter plate, which fastens to the M3.0 x 0.50 tapped holes in the Olympus stage, after the stage is rotated to zero degrees at the vernier, and locked.  The ¼” holes in the adapter plate allow plenty of room for the 3.0 mm diameter threads for centering.  For convenience, knurled thumb screws may be used for attaching the adapter plate to the stage, so a screwdriver is not needed. If the stage is equipped with centering screws, centration of the U-stage can be effected that way.

Alternatively, if the microscopist happens to have a Linkam hot stage, the U-SRP Adapter plate used to attach the hot stage to the Olympus stage may be drilled and tapped to take the U-stage.  Figure 6 (Download PDF) is an engineering drawing of the Linkam U-SRP Adapter.  Figure 7 is a photo of the actual adapter plate, which has two holes drilled 85 mm apart—centered top and bottom in the photo—and tapped M3.5 x 0.60.

click image to enlarge (66K) Figure 6

click image to enlarge (49K) Figure 7

Figure 8 shows the Leitz 4-axis Universal Stage mounted on the modified Linkam adapter, using two cheese-head screws and washers; the screws are M3.5 x 0.60, or the mounting screws that accompany the U-stage can be used—with additional washers if the universal stage has a centering base.

click image to enlarge (167K) Figure 8

click image to enlarge (158K) Figure 9

Figure 9 shows the Leitz 4-axis universal stage mounted on its adapter plate, now affixed to the Olympus stage using two knurled thumbscrews M3.0 x 0.50; fiber washers were chosen for smoother sliding during the centering operation.  This completes the U-stage-to-Olympus-stage modification (the microscope stage has been removed from the microscope for clarity).