We bought a simple webcam microscope off Amazon. However, we actually want to extend the microscope's barrel to hold the additional compound lens system.

After many more complex designs, we decided it would be best to implement a simple design. We knew that complicated designs would make it harder to achieve the precision necessary for high resolution. In the end, we balanced out construction ease with optical capabilities. In other words, we reduced the magnication of the microscope, because we knew it would be difficult to achieve precise resolution even with the simplest mechanical design.

First, we had three washers to hold each lens. The main washer, in the middle of the two other washers, was characterized by two tabs sticking out of either side and hole in the middle that would provide a close fit on the edges of our lens.

However, we wished to avoid putting any pressure or strain on the lens, so we used additional washers on either side of the main washer to hold the lens in place. The holes in the middle of these side washers were files out to cup the convex shape of the lens. Perhaps more importantly, these holes closed down the aperture of the front (towards the object and away from the CCD) of the lens in order to increase resolution.

We used 1 inch PVC for the barrel of our microscope. The PVC was cut to the appropriate length for spacing the lenses. The PVC was then cut length-wise and notched with four precisely measured slots to hold the tabs of the main washers.

Our final can be seen below.