A Developing-Paper Printer
Having a rush order for a large quantity of post cards, I was compelled to adopt some way of making the prints quickly. As I was in a place where a printer could not be secured for several weeks, I set about making one, with good results, as shown in the illustrations.
Switch partFig. 1Switch partFig. 2Switch partFig. 3Switch partFig. 4Parts for Making the Switch So That It will Operate Automatically as the Cover is Moved
Switch partFig. 1Switch partFig. 2
Switch partFig. 1
Fig. 1
Switch partFig. 2
Fig. 2
Switch partFig. 3Switch partFig. 4
Switch partFig. 3
Fig. 3
Switch partFig. 4
Fig. 4
Parts for Making the Switch So That It will Operate Automatically as the Cover is Moved
I first secured an ordinary soap box and took it apart, being careful to keep the boards whole, then rebuilt it to make a box with ends measuring 12 in. square, and 14 in. in length. In one end I cut a large hole to admit a 60-watt tungsten globe, then, taking another board, I fitted a knob and hinges to it and used it for a door. The other end of the box was centered and a hole bored large enough to admit an ordinary socket. Another hole was bored, 4 in. to the right, for another socket. A much heavier material was used for the lid than for the box, being at least ⁷⁄₈ in. thick. A piece of double-strength, clear glass, 8 by 10 in. in size, was procured and set in a hole cut in the cover so that its upper surface would be flush.
The Printer may be Set in the Table Top or Used Separately, as Desired
The Printer may be Set in the Table Top or Used Separately, as Desired
An ordinary single-pole switch was secured, as shown inFig. 1, also a small mousetrap, as shown inFig. 2. The front part of the trap was sawed off so that only the spring was utilized. The base of the trap was then cut out to fit snugly on the base of the switch, into which two corresponding holes were bored for the screws. The next thing was to secure several clips, which were cut from sheet brass, to operate the switch, and a lever to control the switch, as shown inFig. 3. The lever is 1 in. wide and 4 in. long, having a slot at the bottom, to slip easily over the lever handle in the switch, and a hole, drilled 1 in. above the slot, to admit a nail to keep the spring from throwing it out of position. The clips for holding the films, or plates, are shown inFig. 4.
Side View of the Printer, Showing Parts Assembled and the Main Line Connections to the Globes
Side View of the Printer, Showing Parts Assembled and the Main Line Connections to the Globes
After securing a double socket, of which there are many types, a few yards of lamp cord, a piece of felt, 6 by 8 in. in size, and two ordinary lampsockets, I was ready to assemble the printer. The switch was then placed on a board of the same width, the spring of the trap placed on top of it and then fastened with screws. This board was then cut off the length of the inside of the box and fastened in place, with the switch and trap spring on top.
The ruby light A burns all the time, acting as a pilot in placing the negative. When the cover B is lowered, after placing the paper, the felt pad on the under side holding it secure, the projecting arm C comes in contact with the switch lever D and makes the connection to the tungsten light E. After the proper time for the exposure has been given the cover is raised and by this action the tungsten light is automatically shut off, leaving only the red light burning. With a 60-watt lamp I secure a print in about 3 seconds, which is fast enough. Of course, by using a larger lamp, the time could be reduced to a second or more, according to the size. The time given was obtained by experience in using ordinary brands of papers.—Contributed by Harry Marcelle, Honolulu, H. I.