Hi, this is Wayne again with a topic “Make Inventions: Episode 4”.
Some inventions come into the world fully realized with little need for refinement, but truly groundbreaking inventions often evolved dramatically from their initial design. Take, for example, the telegraph by samuel morse. It was the invention that revolutionized communication reducing the time to send a message across the world from months to minutes. The telegraph that we’re familiar with is a simple device, not much more than a switch on one end and an electromagnet on the other. But compare that to morris’s original patent for the telegraph. It’S complex requires a fair bit of precision to build and is surprisingly toxic.
Despite those flaws, it’s an interesting device that predicts an age of automation. Operators didn’t have to learn morris code. Instead, they use a process similar to typesetting, where they compose words for pre-made letters. The messages are then fed through the machine where they’re converted into electrical signals and transmitted. The letters are the most important part of this mechanism.
Each has a unique and precise pattern of highs and lows shaped into the top. Making these by hand would be tedious and error prone, fortunately, they’re well suited for laser cutting, so i create a suitable cutting pattern. The original patent uses a pattern of dots and dashes that predates morris code. I use modern morse code when laying out the letters to make my messages more readable.
When the operator turns a crank, it drives a worm gear that reduces the speed, while increasing the power of the crank, helping it travel at a constant speed. This turns a pinion gear which meshes with the teeth on the bottom of the type rule and moves it forward. I couldn’t find a rack and pinion that was the size i wanted. So i used an online gear generator to create a laser cut pattern. Gears require somewhat tight tolerances and don’t let you get away with being sloppy, so i mock up the placement and cardboard first when i’m happy with the placement, i move the design to a wooden base with a plywood frame with the feeder finished. It’S time to build a mechanism that reads the letters and converts them into electrical signals.
It does that with a pin that rides across the top of the letters. This moves a lever with a bit of wire. On the end, the wire bobs in and out of two pots of mercury to complete a circuit, making a unique switch. Copper end caps, make nice conductive pots for the switch.
I solder a machine screw through the bottom so that i can mount it without leaks. Adding a knurled screw terminal will make it easy to connect transmission wires. Mercury was common in inventions of the time, but today it’s a known neurotoxin, so i’m going to make a safer alternative with conductive paint, since the paint is water-based. I add a few drops of mineral oil on top to keep it from evaporating. It takes some work, adjusting the counterweights and switch wire to get it calibrated, but finally i can send a consistent message. I use a morse code decoder to double check my work, but a morris code transmitter is useless without a receiver.
Samara’S created one of those too a weight powers, a clockwork mechanism that moves a paper tape. A spring-loaded lever holds a pin over the paper and an electromagnet moves the lever, pushing the pin to the paper and converting electrical dots and dashes to real ones. The operator then manually converts them back into letters. I use scrap materials to mock up the gears to get the rates of rotation somewhat correct, a weight in the middle powers, the mechanism with a fly fan to govern the speed. When i’m happy with it, i move the design to a plywood frame. The paper tape is pulled by a pair of rubber bands running between pulleys, with the paper moving reliably.
All that’s left is the marking mechanism. I create a pin holding lever on the laser cutter. A drill makes short work of winding the electromagnet, which is mounted on the base with a custom bracket. A bit of steel is attached to the lever for the magnet to pull on and a retractable pin sacrifices its spring for the return. It takes some calibration to get everything to work reliably, but eventually it makes clear marks time to hook them together and see. If they can talk. The receiver is more practical than morris’s transmitter. In fact, it was so practical that he was unable to get a european patent because it was considered unoriginal and similar devices were used for decades. But it was the receiver that spelled doom for the complex transmitter operators taught themselves morris code by listening to the clicks of the receiver. When it was discovered, a trained person could do the work of a complex machine.
The telegraph quickly evolved its trademark, simple key, which morris patented just a few years later, like many world-changing inventions, the telegraph had to be used in the real world before its strengths and weaknesses were understood. It took exploration, experimentation and perseverance to bring about a communication revolution. I’M steve hofer for may conventions. You .