In this instructable, I completely disassemble my Holga 120CFN to remove a loose screw, and I add a smaller aperture as well.
A screw had come loose from the flash circuit board and was rattling around above the board. It would occasionally short something out and prevent the flash from working as well.
Also, Holga's come with an aperture switch, but the hole in the arm that swings behind the lens when you flip the switch is bigger than the existing maximum aperture, so it doesn't do anything. It's up to you, the Holga owner, to modify this to actually do something. The size of your new aperture is up to you.
Step 1: Expose Shutter/lens Assmbly Screws.
There are two screws inside the back of the Holga that hold the lens/shutter assembly to the body. To access them, remove the back, the image frame, the batteries, and the battery spring board.
Step 2: Remove Lens and Shutter Assembly.
Here we remove the two screws and expose the back side of the shutter/lens assembly. The trip wires for the flash are removed with a soldering iron.
Step 3: Remove the Top
Removig the top of the Holga is a little trickier. Two of the three screws that must be removed are underneath the film advance knob. The knob can be removed by gently prying it up with a chisel.
Step 4: The Loose Screw
The loose screw fell out while I was removing the top. The truth is I didn't even know what was rattling around in there until it fell out. Further examination revealed that the screw must have been overtightened at the factory, as the hole for it was stripped. The flash board was solidly attached without it, so no attempt was made to repair the hole and replace the screw.
Step 5: Remove Shutter From Housing
In this step, we remove the two screws that secure the shutter plate to it's housing. Extracting the shutter plate exposes the aperture arm that will be modified.
Step 6: Prepare the New Aperture
In this step we will create the new aperture. I found some stiff, flat, black plastic that seem suitable. Using sharp shop shears, I cut out a square of this plastic, and then checked the fit. A couple of adjustments later, and the fit was good. Next, I marked the center (roughly speaking), and then drilled it out using a drill bit between my fingers. After the bit pierced through the far side, I flipped the piece over and completed the drilling from the other side. This was done in an attempt to minimize the creation of any burrs.
Step 7: Install the New Aperture
Here I install the new aperture plate in the aperture swing arm, securing it with cyanoacrylate gel.
Step 8: Reassemble
With the 'repair' and modification complete, all that's left is to put your Holga back together.
If you have removed the lens, be sure that it is re-threaded correctly. When it's fully tightened, the mountain icon should be aligned with the focus line. Adjust the focus away from either extreme and then re-install the lens fixing screw.
The top is a bit tricky to get back on, as the flash switch extension is just a loose piece. I was able to get the top back on without too much trouble by first place the flash switch extension in place, and 'switched' to match the setting of the switch on the flash board. Then, while holding the top with the back side facing down so the switch extension does not fall out, insert the top of the camera body into the housing top. Re-install the three screws that secure the top.
Then, re-install the shutter plate, and install the two screws the secure it.
Solder the flash trigger wires back to the switch. There is no polarity to be concerned about here; either wire can go to either contact.
Align the shutter/lens asembly on the body, and re-install the two screws that secure it.
Step 9: Inspect Your Work
At some point before loading your next roll of film, be sure it all works. If you've allowed the glue to get around to the wrong side of the arm and make it inoperable, well, you've got some more work to do.
Here, I have reinstalled the batteries, the spring board, and the image frame With the shutter in 'B' mode and while holding down the shutter release, look through the lens from the back and operate the aperture switch. You should be able to clearly see the aperture arm with the new aperture plate swing in and out of place.
And that's it! Load up some expired 120 film and get out there shoot something!
Thanks for reading this far, and I hope my first instructable was helpful for you.