A simple straight key for sending morse code.
The size is meant to allow printing on smaller printers - the base plate is 100mm long. I use 4-40 machine screws for attaching the pieces and the screw heads form the contacts on the switch. Other screws could also be used.
The intent was to allow a spring to help set the tension at the point just forward of the pivot point in the back. When I built it I found I had made my spring (cut from an old retractable ball point pen, no less) a bit too long. Fortunately, the key bar is thin enough to provide a bit of extra spring and get the 'contacts' close enough to make it pleasant to use.
The photos should explain how the whole thing is put together. I provided 'troughs' to make the wiring look neater. Tape, putty, or some kind of adhesive could be used to hold the wires in place. Mine were solid, so simply bending them to shape worked fairly well. One you set the tension and stroke length to your satisfaction, a bit of blue locktite or fingernail polish should hold the screw in position. Run the wire from each screw head contact to the back binding posts and connect this to whatever plug you need for your radio. There are also two holes in the base plate on either side if you wish to attach it to a heavier base such as a board, etc.
If there seems to be enough interest I may try to make a larger, more robust version. Once I get around to cleaning up the code (OpenSCAD) I'll post it as well.
5-4-15 I never did get around to cleaning up the code, but here it is anyway. Don't expect elegance. But it gets the job done. :)
I still plan to update it. There are a few things I want to improve about it, and I want to make a larger version at some point. Stay tuned.
4-7-16 Added a basic project box per Csopso's request. Not designed for this key in particular, I use it as a generic project box and edit it as I need it. I hope it is useful.