Projects & Related Things: Wood Body Pinhole Camera

I had hoped to be able to add some photos taken by the camera this week but the developed images have not been received yet. When they do I will add them to this post.

UPDATE: July 9, 2020

Rob sent me some photos from the first roll of film through the camera and here are four of them. While they are not modern digital crystal clear images they certainly convey the character and ambiance of early pinhole photographs which, after all, was the intent of the camera.

The useless item is a laminated hardwood ball made out of leftover walnut from the camera and some thin maple leftover from I don’t know what. In this photo of the initial material selection not all the two pieces of walnut with the red arrows were used.

As the goal is to make as big a ball as possible using just these materials some measuring and planning on paper is needed. Here is everything I used to decide the layout and lamination order.

Once cut to size here is the order the pieces will get glued up to make the turning blank.

I started from the center and worked outward. The maple pieces are first and they get glued to the center walnut block. To keep them from sliding around after the glue is applied and while being clamped up a couple of small screws are used to assure correct registration. Once the glue cures the screws will be removed and as you can see, they are outside the ball limits so will be removed.

A couple of big clamps apply pressure and are left on overnight to allow the glue to cure.

The next day the clamps and the screws are removed. Now the outer two pieces of walnut can get glued on. I didn’t use screws to keep them in place but instead use some large C clamps to hold the edges flush while the large bar clamps are tightened. The photo below shows just the large bar clamps in place. Note the triangle on the stack. That gives me a quick visual clue that all the pieces are glued up in the right order and facing the right direction. I know that sounds a little funny but because the pieces are square it’s easy to get one turned 90 degrees from where it should be. That’s the voice of experience talking. Fortunately, I found that mistake before the glue had set and was able to correct the problem.

Another overnight cure and a little trim of the piece gives me not a cube but a square piece taller than it is wide. Since this will be turned between centers on the lathe the blank needs to be taller than the balls finished diameter. Don’t worry if that’s not clear later on you will see what I mean. The photo on the left shows the blank ready to be cut on the bandsaw and the photo on the right is after it’s been cut roughly round. I do that as it’s a lot easier to knock off the corners with the bandsaw rather than using the lathe.

Here is the blank after it has been turned round and to a constant diameter. Everything outside the white pencil lines gets removed in the first step of turning. They are really just for illustration because as soon as the turning starts they will go away.

The turning starts out by eyeballing the arc of material that gets removed but as I get closer a template is used to make sure I have the right arc. This template is cut from a sheet of typing paper that had an early version of the camera front. Here the initial turning is done and the center line of the ball marked in white. You can see the stubs from the turning points which is why the blank starts as a tall square and not a true cube.

Next is to remove the drive and tail centers replacing them with some wood turning jigs I made for making balls. The partially completed ball is set into them turned 90 degrees so the knobs left from the step 1 turning can be turned away.

When step 2 is done, I will have a piece with an X and Y axis trued up. Here is what that looks like with two axes marked in white turned. Side note, did you know that the plural of “axis” is “axes”. Yes, axes is the plural of ax, axe and axis making it the distinction of being the only word in English that is the plural of three different singular nouns.

Step 3 is to rotate the piece again so the Y axis can be trued. The goal is to cut the piece so on each axis it spins true without removing the center line from the previous setup. Cutting away that centerline will reduce the diameter on that axis change a sphere to an oblong. It can take rotating through the steps a couple of times to get a good sphere. When the turning is done the sphere is sanded rotating through all three axes. Here all three are done with each marked in white.

Last is to apply a finish. Since this is not going to have a hard life or get used very much, I decided to use a wax-based friction finish. To apply the wax stick is held against the rapidly turning sphere until the friction melts some onto the surface. It is then buffed out using a soft cloth again held against the spinning sphere. Here is the setup with two pieces of an old sock set between the turning jigs that act as a cushion to prevent marring of the finish. To get an even finish the process needs to be repeated on each of the three axes twice. Buffing the sphere is a balance between applying enough pressure to generate enough heat to melt the wax but not applying so much that the friction in buffing exceeds the friction between the sphere and the sock pads. If that happens then the sphere stops spinning while the drive jig keeps spinning marring the finish on that end. That’s fixed by rotating the sphere and rebuffing that area.