4x5" Wet Plate Holder

thingiverse

This is a versatile plate holder for 4x5 plates that can accommodate sizes ranging from full 4x5 inches down to 3 7/8 x 4 7/8. You can print every part of this holder except for the dark slide and light traps, which require foam for assembly. For the dark slide, you'll need something opaque and up to about a millimeter thick; I've personally used trophy aluminum that works well, but make sure it has no sharp corners as they can tear the light traps. For light traps, use 1/4" foam backer rod, which is affordable - I bought 100 feet for $9 and only needed a foot. To build this holder, first print all of these parts: | File | Quantity| |------|---------| | bottom.stl | 1 | | top.stl | 1 | | retaining_tab.stl | 1 | | lid.stl | 1 | | latch.stl | 4 | | latch_cover.stl | 8 | | latch_cap.stl | 4 | | foam_cap.stl | 4 | Once you have all parts printed, start by assembling the top and bottom pieces. Glue the locking ridge into the trough in the front of the top piece. This should be a nice tight fit. To assemble the bottom, take the four latch caps and glue them into the indentations on the back of the bottom piece. Center them perfectly so that the arches form a continuous space with the gap below for latches to slide into. Cut two pieces of 1/4" backer rod for light traps, almost long enough to extend the entire width of the holder. Squeeze them into the round channels in the bottom piece. At this point, if you fit the top and bottom pieces together, you'll have a complete plate holder body. The foam should fill the slot that the dark slide fits into and keep it light tight but squeeze out when inserting the slide. Run a thin line of super glue along the channel around the edges of the bottom piece and then fit it with the top piece and clamp them tightly together. While this sets, you can assemble the lid. The four latches will go on one edge of the back of the lid held in place by 8 latch covers. These will arch over the latches, with center posts going through the center channel of the latch and anchoring to holes in the back of the lid. Just put a little super glue in each hole and push the posts into place and let them set. At this stage, watch out for glue oozing onto the latches themselves which need to slide freely. If that happens, keep moving the latch back and forth while the glue dries to prevent it from sticking. Once the glue dries, install foam hole caps over holes in the side of the holder where the foam is perfectly centered and then cap it off. The caps are a tight fit so just use a dab of super glue to keep them in place and a wood clamp to squeeze them in tightly. After that, the holder is ready to use. You'll need some kind of spring or sponge to keep pressure on the back of the plate which you lay face down on the bottom ledge when looking into the holder from the back. I've had luck using the same foam as the light trap, just cut into thinner strips lengthwise.