The gate provides illumination and a structure for guiding the film into position for photographing.
NOTE: This is the area that needs the most improvement and will be the focus of future iterations. It's a hack, I know. But it works, I promise.
1: Align and mount the LED panel onto a circuit board as shown with small machine screws and nuts to hold it in place. You will need to drill small holes for the bolts. Add a bit of hot glue to the back if you want to make it more secure.
2: On the back of the circuit board, connect the white leads (ground) and grey leads (power) as well as a piece of wire leading to each side for connecting to our Arduino circuit later.
3: Cut out the gate pieces from the 6" of acrylic leftover from the gate platform with this file. There are 3 pieces. The largest is the main gate and is attached directly to the circuit board and LED assembly. The other two are gates. The one with the larger window is for 35mm and the smaller one is for 16mm film. Currently there is not gate for 8mm.
4: Put 4x 1.5" 1/4-20 bolts through the four holes around the main gate window and tighten with nuts on the front side (Looking at the front, the window is on the right side). On the left side, put two 90-degree braces underneath the heads of the screws (see image).
5: With epoxy, glue a piece of magnetic strip on either side of the window. This will be used later to attach film guides.
6. Thread two 0.75" standoffs facing backwards through the top holes of the main gate.
7. Attach diffusion material to the back of the window of the main gate. In my case, I took the LED diffusion film out of an old monitor and cut it into small squares. I stacked 6-8 of them and taped them to the back of the gate.
8. Cut a 4.5" length of T-slot aluminum and tap one side with the 1/4-20 tap.
9. Using T-slot nuts and bolts, attach the main gate to the aluminum post. Attach the post to the gate platform.
EDGE TABS - these apply a small amount of pressure to the edges of the film so that it is straight and taught when passing through the field of view of the camera. This is also an area being improved in the next design.
When aligning the key stock and flexible insert tabs in the following steps, it's a good idea to use a short scrap of film to make sure the alignment is correct. See photos for detail.
Take the leftover key stock and cut 4 pieces approx. 1cm in length. Epoxy them to the top and bottom of a flat length of metal 3.5cm in length. I used 0.75" wide flat brackets and cut their length to fit (see photo).
Epoxy a metal tab (flexible insert) on top of the four pieces of keystock. When dry, bend the ends down to make a smooth corner at each end.
You can now mount these onto the magnetic strips on the main gate assembly. You will align them with the film later.
If you haven't already, cut the acrylic gate face plate that appears in the same file as the main gate assembly in the previous step (there are two - one for 35mm with a large window and one for 16mm with a smaller window).
Cut the cable from 4 telephone jacks (male) and epoxy them to the back-side of the face plate where they will meet the edges of the film. Use a scrap piece of film to achieve proper alignment (see photos). The back-side of the face plate will have slightly more acrylic to the right of the window than the left (see photos).
Epoxy metal tabs onto the spring arms of the telephone jacks, leaving 1/8" or so hanging off. When the epoxy has dried, bend the excess overhang down so that a smooth corner meets the film edges as it arrives at the tab (see photos).
Repeat the above steps for both 35mm and 16mm gates and tabs.
NOTE: If you've gotten this far and you're thinking "Telephone jacks? He can't be serious," just remember that this design is meant to be a solution to a worst-case scenario. It is not intended for use on highly valuable films or for preservation. The telephone jacks actually provide a perfect amount of pressure on the film edges and the tabs provide a smooth metal surface without requiring the construction of an all-metal gate.