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

Wood Body Pinhole Camera - #9 Installing Film Boxes & Rounding Camera Body Edges

With the front of the camera glued on and the film box done I can mount it into the camera body.  The installation process starts by fitting the box in its final location then using the marking pin to dimple where the screw goes.  The pin is shown set in the previously drilled countersunk hole ready to be struck thus marking the screw’s location.  The second screw location will not be marked until this screw is installed.

Once the screw’s location is marked, I can drill its pilot hole.  The blue tape is my depth gauge so I don’t drill through the film box.  The other larger drill will be used to enlarge the hole in the camera body so the screw floats in the camera body and its threads do not bite into the wood until it gets to the pilot hole in the film box.  That way I can be sure the film box will be pulled tight up against the bottom of the camera body.

Here’s what the pinhole lens, the film box and the camera body look like assembled.  If  you look at the upper right hand corner of the camera there are a couple of arcs marked in pencil.  That was me trying to decide which radius to use on the corners.

To make the camera feel a little softer to the touch the edges will be rounded using the router but before that there is a little work to be done.  Both the front and back were cut just slightly oversize and they need to be sanded flush with the camera body.  That’s done by using three different grits of sandpaper, 120, 220 and 320 clamped down.  The camera is run across the 120 paper until the surfaces are flush.  Sanding is then done with the 220 to get rid of the 120 scratches then on to the 320 until the surface is smooth.  The blue tape was applied after sanding and the reason for that is explained below.

Just one more thing needs to be done before routing.  Since the front is glued on it’s not going to move but the back comes off so to hold it in place, I used the blue tape to securely hold it.  The four corners are rounded over with a 3/8” radius round over bit.  As the routing is all end grain which is prone to chipping out several passes were made raising the bit a little at a time.  Here you can see the completed routing.  The routed edge on the left has some burn marks.  That’s fairly common on cherry as it burns pretty easily particularly when routing end grain.  Note the right routed edge does not have the burn marks and that’s because it’s been almost finish sanded using the three grits of sandpaper described above.

That takes care of the corners.  Next are the front and back face edges.  They also get routed but with a much smaller 1/8” radius bit.  Same process a above except the final sanding goes one step farther with 400 grit paper on all the edges and faces.  The front view now presents a softer more comfortable appearance and feel.

The same is true for the back although there is still some work to be done on the edges that are visible when the back is removed.

Finishing the shutter assembly is next.  That entails adding the remaining finger recess to the shutter slider, cutting the pieces to length plus softening all the exposed edges.  That softening was the most time-consuming part of this work.  I know it may sound a little strange but the edges are really sharp.  Enough so it’s not that hard to cut yourself on them.  So, in order for the camera to feel comfortable in use that edge needs to be removed.  In other projects I have used both chamfers and rounding.  Because the other edges are rounded that’s what will be done here.  The rounding amount is small only about 1/32” which is accomplished using 220 and 320 grit sandpaper.  In order to see in enough detail to create a consistent radius the jeweler’s magnifier, a lot of light and about an hour’s time are needed.  This is what the finished assembly looks like when the shutter is closed.

When the shutter is open the slider is flush with the edge giving tactile feedback that it is set at the correct place.

Because the back needs to be securely held on there will be 8 rare earth magnets installed to accomplish that.  In the photo of the back up a couple paragraphs you can see that there are no provisions for a finger or thumb to get a grip when it comes time to remove the back to load or change film.  Fixing that is next.  It’s done using the oscillating drum sander along with a jig that holds the camera body at an angle.  If you are interested the basis of the jig is from the Router Plane project that I had kept.  A fence clamped to the sander’s table keeps the jig aligned with the center line of the oscillating drum.

This is a closer view of how the finger grip space is made.  When I get close to the finished depth the coarse sanding tube is replaced with a fine grit one for a better finish.  It’s not the final finish, that’s done by hand sanding down to 320 grit.

Here is the body and the back fitted together where the finger grip inset can be easily seen.  All the hard edges that can be touched have now been rounded.  That includes the edges on the back that are visible plus the ones inside.  The same method using the jeweler’s magnifier, a lot of light plus 220 and 320 grit sandpaper is used. 

Next Up – Installing the Shutter, Finishing & Final Assembly

Wood Body Pinhole Camera - #8 Milling the Shutter, Finishing the Film Box & Glue-up

Milling out the shutter assembly is next which starts by ripping the shutter and guides from the blank on the table saw.

Making the guides is a multi-step process that starts with the two guides still in one piece.  First, using the table saw a majority of the rabbit is removed.  Here the outer passes have already been made.  Before the next pass the fence gets moved closer to the blade and two passes removes more material repeating until the cuts meet in the center.

Once that’s done, I move to the router.  It’s used to flatten the ridges left by the table saw, cut deeper and trim the sides to a sharp corner until the final width and depth is reached.  Below shows the first pass at the top of the piece flattening the bottom.

To keep my fingers away from the router bit an adjustable push block is used to safely push the piece thru.  I only have 10 fingers and nearly cut my thumb off once on the table saw.  I really, really don’t want to go through that again.

Once the final width and depth is reached it’s back to the table saw to cut the blank into the two guides.  The center of the piece is set on the center of the blade and then cut.  Once again, I get a little help for safety’s sake.

The shutter piece gets rabbits cut just a hair deeper than the ones on the guides using the router then the previously ripped guide edges are run through the thickness sander until they match the ones on the shutter.  Here is how the guides and shutter look after the fitting.

Marking the shutter piece for machining is next.  There are several holes either all the way through or part way through that need to be laid out.  Below is the front and back layout plus the punch I will use to mark the center points and the three different drills used.

Once the hole locations were double checked I could start drilling.   Here the top photo shows the closed shutter with the guides clamped in place.  The bottom photo shows the shutter slid over and open.  Neither the guides nor the shutter have been cut to length yet. 

If you look carefully you can see where there is a slight arc cut into the top guide.  That’s to provide clearance so the pinhole assembly can be removed if it gets damaged or for some other reason needs to be changed.  I had two options to allow for removal of the pinhole assembly.  This way and screwing the guides on from the inside of the camera so they could be taken off.  I did not go the screw route because the guides aren’t very wide and I was concerned that they might split when the screws were installed.  Also, if you look to the left of the pinhole you can see the hole where the magnet will go to lock the shutter either open or closed.  There are a couple of matching holes on the back of the shutter for the mating magnets.

Drilling the thumb holds in the shutter is next.  At this time, I will only be drilling the right one.  The left one will get drilled later after the guides are installed.  The goal is that when the shutter is open the left side will be even with the edge of the camera body.  That makes an easy tactile way to double check that the opening in the shutter is aligned with the pinhole.  The top photo shows the setup and the bottom is a closer look after the hole has been drilled.

Gluing the front onto the body and the axles into the knobs then clamping things together are shown below. 

While the glue cures on those pieces the channel can be cut in the film box.  That’s done on the router, here is the setup.  There are a few things to point out with the setup.  First, the cam clamp is used for safety so I can get my fingers a little farther from the router bit.  Second, as you can see the cam clamp is set on a piece of ¼” plywood.  This holds the clamp above the table so I don’t route a channel in it too.  Last is something that you can’t see.  When the cam is tightened down the clamp twists just a little bit so when the bar jaws are flat on the plywood one side of the film box is up off the router table.  It’s such a small amount I did not notice it until checking the depth of cut with a digital caliper.  From one side to the other there was about 15 thousandths of an inch.  Like I said not a lot but, this is what the film will ride on when taking the photo and I want it right on.  The fix is pretty simple.  I just made sure the film box was flat on the router table by pressing down on the high side of the clamp.

Taking off the clamp you can see the router bit and the channel.  It’s not very deep only about four hundredths of an inch but deep enough to guide and hold the film in place.

After routing there are sharp edges on the leading and trailing edge of the channel.  Since the film will ride on these edges they need to be softened.  That’s done with some fine sandpaper.  When done this is what it looks like.  I still have to do the final sanding on the film box but other than that it’s ready to be installed in the camera body.

Back in Post # 6 I mentioned that I might make a second film box for a wider negative.  Well, here it is along with the first one.  The first one, on the left gives a standard 35 mm wide negative while the one on the right gives a 48 mm one.

By now the glue holding the axles in the knobs is cured enough I can epoxy the steel washers into their recessed spaces on the underneath side of the knob.  But first I need to make a little caul to apply pressure to the washer around the axle.  It’s simply a small piece of plywood with a hole drilled in it and in my case the easiest way to drill the hole is with the lathe. 

Once drilled the piece gets cut in half, epoxy is applied in the recess and the washer set in place.  The caul is set over the axle and the assembly clamped.  As the caul is longer than the axle all the pressure is applied to the washer spreading the epoxy out and making sure there is good contact.

This is what the knobs look like completed and ready for finishing.

Next Up – Installing Film Boxes & Rounding Camera Body Edges

Wood Body Pinhole Camera - #7 Body Sub-assembly, Assembling the Film Boxes, Milling the Front & Back

Gluing the top of the camera body to the sides is next.  It’s going to be glued up in two steps for the same basic reason as the film box was.  Here is it clamped up with a temporary blank inserted to help keep the pieces square.

Before the bottom gets glued on there are a couple of things to be done to finish it off.  First is to drill 5/64” pilot holes then countersink with a ¼” bit 1/8” deep for the screws that will hold the film box in place.  Once the screw locations are marked on the film box using the small punch (just to the right of the drill circled in red) the pilot hole will get drilled out to 1/8” to provide clearance for the screw threads.  The left photo is a drawing of how it all fits together and the right photo shows the setup for the countersink.

Next is to glue the pin that was turned on the lathe and fitted in Post #5 Starting the Film Knobs into the base.  With that done the bottom is glued on, clamped and left to cure.

After the film box has cured overnight it’s removed from the clamps and using a sheet of 220 sandpaper clamped down to my table saw extension I sanded the faces smooth.

Because one of the two pieces in the corner joints of the film box is end grain and end grain makes a weaker joint, I was concerned about its long-term strength so decided to reinforce it some using pin nails.  Pin nails are shot in using an air gun.  Here is the ½” long one I will be using set against a ruler.   They are quite thin at about 24 thousandths of an inch in diameter.

The pneumatic pin gun, a stick of the nails and the film box look like this.

The next day with the bottom piece’s glue cured the clamps are removed and the joints flattened using the same method as the film box above.  Here it is along with the knobs and film box that’s been marked for the film guide channel.

Moving on the front and back pieces are cut to their final size.  Using the router a rabbit is cut around the perimeter of each so they can be set into the body.  This photo shows the router setup and where the final cut has been made on the ends but not on the top or bottom.

Here it is finished front with the film box opening laid out and center lines drawn in.  They will be used as a double check for locating the center of the pinhole lens since it’s a bad thing when the lens and the film don’t line up.

Milling the mounting flange for the pinhole lens along with the magnet hole for the shutter is next.  It’s not all that hard but does need to be accurately located.  Odds are it’s going to take a lot longer to measure and double check than it is do the milling. 

A little thought needs to go into the order of operations to keep everything concentric and centered in the right place.  First is to drill a small pilot hole all the way through the front.  This will act as my reference point for boring in from each side.  Next is to clamp a stop block to the right side so it will be easy to reset the front in same position as I pick it up and measure the hole depth.  The 1.5” hole is bored from the outside to the proper depth.  Then the 1.5” bit is removed and the 1.25” bit installed.  It is then used to bore the inner opening a little deeper than its actual final depth.  That will make sense in the next step.  Here you can see where that has been done along with the small pilot hole.

The piece is flipped over and the pilot hole is used to align the piece in place.  Now the 1.25” bit is removed and the 1.5” bit put back in the drill press.  The hole is then drilled to the final depth.  Because the inner smaller hole was bored a little deep it overlaps what is being drilled now.  That’s why I didn’t have to worry about getting it to its exact depth.  The photo below shows how it all comes together.

Dry-fitting the pieces together make it look more like a camera than a collection of spare parts.  In the bottom photo the camera is not centered so the pin hole looks out of alignment but it does line up with the center of the film box.

A little work on the back is next.  It needs to have four holes drilled for the magnets that will hold it on and they need to match up with the ones already drilled in the top and bottom.  You can see the holes in the bottom photo above.  After marking them out the centers need to be punched so the drill bit has a starting point and won’t wander.  Since I really want them to match exactly a little help from the jeweler’s magnifier is needed.  It may look a little funny but it sure helps getting it right.

Once marked a trip to the drill press and using a dial caliper to check the depth gets them all drilled square, plumb and the right depth.  Here you can see how they line up with the existing holes in the body.

Next Up – Milling the Shutter, Finishing the Film Box & Glue-up