Rear standard and base frame for 5×7 conversion back. I use a stone ‘reference’ table to check parts for flatness. The Lie-Nielsen rabbet plane in the back is perfect for truing up small parts. Excuse the crappy 5am picture…@_@
I came close to selling my first home made 5×12, but instead decided to make a conversion back for it so it would see some more use. I missed using this camera and have always wanted to try 5×7, so I started making a new rear standard for it this past weekend.
Dry fit of rear standard. Box joints are made with a sled-type jig on a table saw- I like the look of many thin joints so don’t use a dado stack, just a single 1/8″ blade with a flat-top grind. Glue up will be a pain in the ass- especially with open pored wood like mahogany where every bit of errant glue is absorbed in depth, but the finished result should be worth it.
Back frame glue up. I made lap joints for the back substrate then a stepped lamination for the riblock plane. More work than cutting from a single piece but I did it mainly for economy of wood. The mahogany I’m using is left over from the stock I made the original 5×12 from 6 years ago, so it was worth a few extra steps to be able to get all the parts from matching stock. It is difficult to work and reminded me why I avoided this chunk of wood 6 years ago- the ribbons of alternating grain make planing a little tricky- I really need to tune up my hand planes. Re-sawing the wood to rough dimensions exposed some crazy tension within the stock and much was wasted truing the parts up. Anyway, I’m gluing the back frame up in stages- first the lap joint assembly, cured it overnight then added three sides of the laminations. I’ll add the riblock strip next. I use a 5×7 jig that is planted in the center of the frame with a lead ingot during each glue-up to keep everything centered and square.
Ground glass frame rabbeted for T-dimension of film holder to match GG plane. Checked a dozen times with calipers to make sure it’s on the mark. Tenon shoulders are offset to accommodate the rabbet. The joint is only slightly trickier than a regular mortise and tenon and I find it easier to mill the rabbet to the T-dimension disassembled instead of trying to rout the ground glass plane after glue up.
October 29
Started on the tedious stuff. Always a jolt remembering how the fun goes out of a camera project after the woodworking is finished. Many trips to the hardware store as I never seem to have the right assortment of washers, screws and metal stock. Nothing terribly exciting to report, but it’s progress nonetheless.
Glued up the rear standard, ground glass frame. Jigs helps to keep everything square during glue up. For the ground glass frame I like using wedge and fence arrangement to clamp with- the weight of bar clamps on thin frames can warp the assembly quite a bit. A chunk of melamine cut to the ground glass size and screwed down to the jig keeps the frame flat while curing.
Started making hardware for the back. Thought of a new (to me) way to secure the back to the rear standard. An aluminum angle that captures a slot in the back is inlaid flush with the standard on both axes. There will be some flip locks on the top of the back to lock it in place. Should be easy to change orientation, and will be able to install the back in any orientation, even upside down, since the slot circumscribes the back.
Haven’t used the mill in a while so spent some time cleaning and lubing the XY table and adjusting the gibs and lead screws. Helped the quality of the cut immensely, not to mention the ease of cranking the table back and forth. Milling the base-tilt stays here using a plywood jig that’s anchored to the XY table with T nuts and clamping screws. There’s a dado routed in the plywood that is the same width of the stock, which makes clamping and locating parallel cuts much easier.
The pivot points for the back. I like post screws nested in a nylon sleeve bearing. Any slop in the pivots makes the camera feel really loose, even locked down, and the slipperiness of nylon helps keep tolerances tight without binding. I milled a flat on the post screw to keep it from spinning when the pivot screw is thread through.
Sizing and mounting the carriage deck. Assembling and double checking the pivots with all the washers, sleeves, brackets and stays in the assembly that determines the overall width of the deck. But just to be sure I leave the deck stock over length and clamp one of the angle brackets to the deck and pilot and tap,screw and mount to the standard, then assemble the other angle bracket and screw to the standard and scribe the position on the deck. Then I can cut to exact length and pilot and tap that bracket to the deck.
Starting to come together with the 5×12 bed. Hard to believe it’s the same wood….
November 5&6
Finishing up the small stuff. Finalizing the back hardware, finishing the springs and levers, making bellows frames, grinding glass, finishing, painting the baffles and the list goes on.
Levers for back locks. Don’t like this arrangement nearly as much as the Deardorff-style corner pins ans springs, but I made the back too thin to comfortably bore for pins.
Back baffling. Everything inside the light path is painted black. I use aluminum angle for the back baffles, which serves double duty as the bellows lock rail. The bellows frame is tipped into a piece of 1/4 channel stock on the bottom edge, then tilted back against the angle stock. Some threaded inserts will crew down and secure the bellows frame along the top. The other side of the frame that abuts the back is lined with velvet.
Bellows frame. Stepped on the front only- the light trap is build into the rear standard for the back. The frames are painted flat black on the outside only- the sides that attach to the bellows are left plain wood because the contact cement tends to dissolve most paints. After the bellows are attached I touch up any bare wood showing with a stain pen.
Done for now. I had a chunk of 5×12 glass I never ground so I was pretty thrilled not to have to wait for a run to town to get some. I still have piles of aluminum oxide and ground the glass with a glass element taken from a crappy zoom lens. I ground it with 25 and 12 micron grit, any finer and the glass starts to get clear again. I still need to scribe a grid on the glass. I also need to put a final shape to the corner brackets and polish the metal parts up some. I can’t wait to use it a bit more- it was getting dark just as I was finishing up, but I did get to expose a few sheets with a new-to-me Berthiot Eurygraphe double anistigmat (top picture). After a working-in period, I’ll make any necessary adjustments then take it apart spend some quality time on a lacquer finish. Still, even with just a sealer coat on it the wood looks fairly close to the original camera. The grain is a bit wilder than the rest of the camera but it will hopefully mellow out nicely with exposure.
Rail Bridge, Clackamas River, shot with both cells of Eurygraphe
August 1, 2012
I’ve been meaning the do this to at least one of my cameras for some time. After they get broken-in, bellows can get a bit too flexible and start to sag a little, sometimes causing some vignetting- that is, bellows sag can partially block the light path from lens to film. You can make the bellows with heavier cloth and more rigid cardboard stiffeners, but the trade off is flexibility, movements can be restricted, especially with short lenses. Chamonix used to use this solution for the 1st 8×10 camera they made, but for some reason they discontinued it on the new model. Anyway, the idea seemed ripe for ahem borrowing. Most of my pano cameras live with wide angle bag bellows most of the time, so I decided to start with the 5×7.
Knob bristle. Starting to forget what tightens what.
Frame swings out to support sagging bellows. The rod that comprises the bottom of the frame is hollow, making it easy to thread to accept screws. The stays are 1/8″x1/2″ aluminum, screwed to the tube along the bottom and threaded to accept the tightening knobs on the top.
