Wood Body Pinhole Camera - #10 Installing the Shutter, Finishing & Final Assembly

Attaching the shutter assembly is next.  The first piece to go on is the bottom guide rail.  To assure that it is in the right location and parallel to the bottom two things are done.  First, a backer board is clamped to the camera body that acts as a reference plane.  Second, the previously sized spacer gets 4 layers of blue painter tape applied to its bottom surface.  The tape holds the spacer up off the camera body.  That gap will help to minimize any glue squeezing out from getting smeared on the camera face.  Here the tape face is shown up but when used it will go tape side down.

With the spacer in place a thin layer of glue is applied to the guide rail, it is aligned with the light pencil mark on the left and tightly held there for two minutes.  That gives the glue enough time to initially grab tacking the rail firmly in place. 

The clamps, backer board and spacer are removed then the guide itself is clamped down to hold it in place while the glue finishes curing.  The glue lines are then carefully checked so any excess glue can be removed.  In this case I used an X-Acto knife with a reshaped blade to scrape the few semi-cured bits away.

After the glue cured overnight, I added a couple layers of blue tape to the sliding section.  This gives me about 8 thousandths of an inch space allowing the piece to move easily between the guides.

Glue is then applied to the top guide rail, it’s set in position, held in place for a couple of minutes just like the first guide then clamped.  Here is what that looks like after the glue squeeze out had been removed and the glue cured.

The next day the clamps are removed and the sliding shutter is tested for smooth operation.  That brought to light a couple of tiny glue spots that once removed allowed the shutter to easily move.  The top photo shows the assembled camera with the shutter closed and the bottom one with it open.

This is what the interior looks like with all the fitting and sanding done.  The two black lines on the top of the camera represent the approximate field of view which since the camera does not have a view finder will be used for framing the photo.

Applying the finish is next but first the camera needs to be totally dissembled so each piece can be completely finished.  Here’s all the parts ready to start.

Two different types of finishes will be used.  A Danish Oil Finish is used on all of the pieces except for the film boxes.  As discussed in Post #2 I was worried that a film finish like lacquer could gas off and have a detrimental reaction with the 35mm film or its emulsion.  Also, an oil finish is reparable if the camera needs a refresh some years down the road.  Applying the oil finish takes quite a bit longer than a sprayed lacquer finish but I think it’s worth it for this application.  Applying the oil is not hard as a cloth is used to flood the surfaces then reapplied as it soaks in for about 15 minutes.  After letting is set for another 10 minutes or so any that is left on the surface is wiped off.  I usually come back about 5 minutes later to check to see if any has bled out of the wood pores then give it a final wipe down.  For this project I will put on three coats and see what it looks like.  Here is what it looks like after the first coat.

The film boxes have a black dye applied to them.  That’s because a dark non-gloss finish is needed between the pinhole lens and the film.  I had considered using flat black paint but was concerned that where the film rubs across its edges the paint could get worn off.  As the dye will soak into the wood and not set on the surface, I am much more comfortable with that being a better long-term solution.  The dye concentrate is added to alcohol then applied.  It also works with water as a carrier but that raises the grain which I did not want. 

After three coats, they have a really dark non-gloss finish which is what I wanted.  It did not take all that long to do as the alcohol evaporates quickly particularly when the humidity is only about 15%.

It ended up taking three coats of the oil spread out over four days to get a nice looking even finish.  With the last coat on it sets for about a week to cure out.  That’s followed by a thin coat of wax which gets buffed out to matt finish.

Installation of the magnets is next and there are 15 of them that need to be installed.  I started with the ones holding the back on.  They along with the ones for the shutter require a little more attention that the ones that hold the knobs on.  The knob magnets get installed in the camera body and attract the steel washer in the base of the knob.  The ones for the back and shutter act as a pair so I need to make sure that the North and South poles of the magnets get installed facing the right direction.  Installed wrong and they repel rather than attract each other.  I also wanted all the ones in the back to have their polarity identical between sets.  Here are the ones for the back set in place ready to be press fitted. 

The press fit is done with a clamp which allows me to carefully apply just the right amount of pressure to set them in place.

This is what they look like installed.

Installing the pinhole lens is easy.  It drops into place and is secured with the locknut installed in the inside of the camera body.  Here you can see it installed along with the magnet next to it that holds the shutter either open or closed.

Once the magnets are installed on the back of the shutter it gets slid into place.  This is how it looks when the shutter is open and a photo being taken.

The last pieces to be installed are the film box and the knobs.  The film box gets attached by two screws while the knobs just drop into place and are held there by magnets.  Below you can see the inside of the completed camera plus the extra film box that’s for wide angle panorama photos.

Here is a front view with the shutter closed.

This finishes the build of the project.  Below is a photo that shows one of the prototypes used for testing and the completed camera.  This has been an interesting project, small in size but requiring a lot of attention to detail.  Cost in material was pretty small only about $20 for the wood, magnets and finish plus another $30 or so for the pinhole lens.  However, the time required for designing and build was another matter.  I did not keep a detailed track of the hours worked as I did not want to scare myself too early in the project.  That said given an average days’ work spent times the build duration gives a total of between 175 and 200 hours. 

Once the oil finish had thoroughly cured, I passed the camera off to Rob for testing to see how it works and what the results are.  I hope to be able to include some of the photos in the next post although as I understand it the COVID-19 has impacted production at the company developing the film.

In looking at the leftover pieces and wondering if there was something to do with them, I came up with an idea for an item with no functional use.  This short one posting project starts next time.

Next Up – Photos??? & A Useless Item