While I was napping with my toddler this afternoon I had a dream about Viewmaster slides, and that sent me down a stereoscopy project rabbit-hole that eventually led me to googling the viewmaster patents and looking for the specs for the slide reels.
To save you all the work – here is an SVG Viewmaster Slide template at 1:1 size (90mm diameter), ready for your plotter or laser cutter. Preview PNG below:
I haven’t marked out the safe text area for the photo labels in the SVG because it’s not consistent between the different viewers available over the years but generally titles go in a small curved trapezoid directly above the center hole, you’ll have to experiment with this.
It is worth noting that the slide pairs are directly across the center line from eachother, and that the progression of slides skips a pair every time the lever is engaged, so counter clockwise from the right-side (3:00) slide hole, the pairs are A (right eye), E (left eye, upside down), B (right eye), F (left eye, upside-down), C (right eye), G (left eye, upside down), D (right eye). This seems really confusing, but the mechanism for skipping frames cleverly works it’s way all around the circle and avoids getting an upside down image after you’ve clicked through the seventh image in the set. For reference, you can take a look at the original patent image, below: