I love my DigiMicro USB Microscope! The only problem with it is that focusing it is pain. The little adjustment wheel is impossible to turn without moving the microscope. So I created this little add-on to make focusing a breeze. Now I really love my microscope.
The design of the bracket and worm was done with FreeCAD. The knob used John Sanford's Parametric Knurled Nut Knob ( http://www.thingiverse.com/thing:439239 ). I can post the source files if anyone wants them.
- U-bracket (AdjMnt(repaired).stl)
- worm gear (AdjScrew(repaired).stl)
- knob (knurled_nut_knob (repaired).stl)
- 4 M4 nuts (Two lock the worm gear; two lock the knob)
- 2 M4 washers
- 1 M4x70mm screw (all thread)
Print the three parts.
Fit the U-bracket to your microscope. You may need to trim the corners to fit. It is designed to require some trimming. Make it fit tightly!
The screw is threaded into the worm gear. You may need to drill the hole in the worm gear out slightly, but the screw should thread in tightly.
Enlarge the holes in the U-bracket so that the worm fits firmly against the groves in the adjustment wheel of your microscope. Do the adjustment slowly and don't overdo it. You'll have to back the screw in and out a few times to get this right.
Remove the screw from the worm gear.
Assemble all the parts onto the screw. Be sure to put the screw in so that the knob ends up on the side you want it on.
Put on a washer, slide the screw through one hole of the U-bracket, thread on a nut, then add the worm gear. Screw the worm gear into position and add another nut as the screw goes through the opposite side of the U-Bracket. Drive the screw in until the head is against the washer and the U-bracket. The worm gear should be centered over the adjustment wheel. Tighten the bolts on each side of the worm gear to lock it in place.
Put a washer on the screw, then a nut. Tighten the nut until is firmly against the washer and the side of the U-bracket, then loosen it a bit so the screw will turn freely.
Put the knob on so that the nut pocket will go over the nut that is already on the screw. Put the last nut on the screw and tighten it against the knob to lock it into place.
You can now easily adjust the focus of your microscope!