7x11 Camera Build

[Michael Roberts]

The camera base, L-shaped rear rails, and T-shaped “keeper” rails all trimmed and glued up. These have not been sanded or finished yet.

The T-shaped keeper rail (see 3rd pic) is 1/4 x 1 x 9 3/4 mahogany on top, with a 1/4 x 1/2 x 9 3/4" piece of basswood centered underneath. These will be screwed into the base with 5/8" brass wood screws. The L-shaped rear rails have mahogany of the same dimensions on top and 1/4 x 1/4 x 9 3/4 and 1/4 x 1 x 9 3/4" basswood pieces glued to the bottoms. I am using two sticks of basswood for the underside of the rear rails because they come precut in 1/4 x 1/4 and in 1/4 x 1" sizes, so all I have to do is chop them to the length I need and apply wood glue and clamp the pieces to dry.

These rear rails will slide freely (I will wax both the underside and sides of the rails as well as the top and sides of the base) and will lock down using brass strips and brass knob "clamps" on top. The front rail (rectangular open design) will fit in the middle between the two keeper rails, as per the King design.

Basically, this is the King design except I am replacing the brass "shoe" hardware that supports the rear bracket on the King and slides forward and back with a much longer wooden rail. Also, I am leaving the front of the base open for these rear rails instead of closed.

[Michael Roberts]

Base layer for the spring back.

[Michael Roberts]

Finished spring back w/o gg frame. On top of the base layer (above post), I added two 1/4 x 14 mahogany sticks to form the flap end of the U-shaped surround for the film holder and two pieces each of 1/4 x 1/2" cherry (left from a prior project) for the top and bottoms of the surround. Then I added 1/8 basswood for runners for the film holder area, leaving a 1/8 gap for the light trap rib on the holders.

The second pic below shows the light trap on the inside of the spring back. The light trap material is 1/4 thick basswood, painted flat black. Before final assembly, i will paint the entire inside flat black.

After gluing these pieces up, I ran the spring back through my table saw to square up the outside edges. This left the piece slightly short of the 9 3/4 x 12 3/8 target dimensions. I have some 1/32 mahogany that I will cut some 1/2" wide strips from to make a veneer for the top and bottom.

[Michael Roberts]

Ground glass frame: 1st layer, middle layer, 3rd layer. These pieces are 1/8” basswood. Bottom two layers are 3/4" wide; top is 1/2" wide to leave room for the groung glass to fit.

[Michael Roberts]

Front rail is finished. Seems to fit well.

[Michael Roberts]

Rear brackets are in progress. The bracket arm is 1/8” birch plywood, ripped on the table saw from a 12x24" standard craft sheet, then chopped to 7" length and ends rounded with a small handheld sander, and rivet hole drilled with a 1/2" handheld drill.

I looked around for pre-made brass hardware, but did not see anything that looked right. The brass rivets come from McMaster-Carr. My plan is to secure this assembly to the rear rails with wood glue (and perhaps screws, we'll see) and to epoxy a threaded stud to the upper end. The threaded stud will fit (from the inside) through the routed slots on the sides of the rear frame and be secured with knobs on the outside of the rear frame.

[Michael Roberts]

The shortest ¼-20 tripod socket I could find at McMaster-Carr came in ½ barrel length. I drilled a hole in a scrap piece of wood, inserted the socket, then used a hack saw and grinder to cut it to 1/4” length to fit my camera base. Seemed to work just fine.

I’ll have to wait and see if my camera base holds up or if ¼” turns out to be too thin.

Time, and working in the field, will tell.

I will need to route a 1/16 or so section from the middle of the front rail bottom (front and rear) to clear the base of the socket. I considered, but rejected, the idea of routing out the camera base so the socket base would fit in smoothly. Since the camera base is only 1/4 thick, I don't want to route it and make it even thinner.

[Tin Can]

You are working fast!

[Oren Grad]

Bravo!

It will be interesting to see where the weight comes out. Among the classic cameras, the Eastman 7x11/8x10 camera is disproportionately heavy for its formats, while the Korona 7x11 is lightweight but extremely scarce.

[Michael Roberts]

Randy--yes, I am planning to visit my 91 year old father next week, so trying to get as much done as I can this week.

Oren, thanks! I'm really hoping to come in somewhere close to the weight of my 8x10 King, i.e., around 5lbs or so. I'm making this landscape only instead of reversible-back to save weight. On the other hand, I'm also extending the bellows from 24 to 30 inches, so I don't know if these will cancel each other out in terms of net weight or not. I also beefed up the thickness of the rails to a full 1/2 inch, and I beefed up the U-shaped surround around the film holder to 1/2 inch as well (the King has cutouts for the gg spring screws that only leave about a 1/16th raised rim around the film holder--a design flaw IMHO). This is my first build with this design, so it's all just a guess regarding the finished weight (and stability) until it's done.

Of course, one of the benefits of DIY is you can continue to tinker and refine. I've never seen a Korona 7x11 (or 8x10 for that matter), but my first 8x10 was a Kodak 2D; it weighs 12lbs, and I know the 7x11 version was a good deal heavier.