Summary

This is a compact, simple to make, 3D-printed straight key style Morse Code key. Improved support for a wide range of springs.Based on Tskauli's original "Morse Key" 3D model.
I use this handy keyer along with the Morse Code Trainer to perfect my Morse Code keying.

Print Settings

Printer Brand:

Fabtotum

Printer:

Fabtotum Personal Fabricator

Supports:

No

Resolution:

0.28

Infill:

15%

Filament: Duramic PLA/PLA+ various

Notes:

For help forming the parabolic hollow, on the underside of the arm, I made these setting in Cura:
Overhanging Wall Angle: 35 degrees
Overhanging Wall Speed: 70%
You may see a little errant material placement at the peak of the parabola but It will be functionally fine and unseen.

Post-Printing

The 3D print should work fine without support. The two holes in the base for the hinge and the hole in the arm that the stop screw go through needs to be cleaned out to where the screws will not bind. The arm needs to move smoothly between the base hinge supports.

Assembly: Is fairly straightforward and intuitive.
For greater general understanding, the details provided by tskauli's MorseKeyAssembly.docx should give sufficient insight. There is a notable assembly difference in the routing of the wiring.
As the spring can no longer be moved to adjust keying pressure, spring selection and modification is relied on.
Refer to this doc for a guide on potential springs to use
I used a spring from a Pilot G-2 pen (.4 wire, 5.5 x 20mm)
I also used a thin pen spring 3x26mm. To make it stiffer, I cut it in half, twisted ½ into the other, then I stretched that out to a 16mm long dual spring. I wrapped Scotch tape around it, to keep it inter-twined and so I could hold it all with needle nose during assembly.

Hardware:

Wire or cable as desired. (I used stranded silicone 26ga. wire for flexibility)
Five M3 screws, 1x 16 to 18mm, 2x 8mm and 2x 5mm length
Alternate Screws: #4 Pan-head machine or sheet metal screws; Philips or hex key driven.
1x 5/8”, 3x 3/8”, 1x 1/4” (or filed or ground down a 3/8” screw, this works best with sheet metal screws)
The long 5/8” screw should be a machine screw, for easier end-stop fine adjustments. I didn't use a washer with it, so a 1/2" screw worked for me.
I did find that #4 screws (either sheet metal or machined) works as good as or better than the M3 ones. Number #4 screws are very slightly smaller in diameter than M3; which was perfect for my 3D print as the holes tend to be a little undersized.

Optional hardware: wire terminals; a small washer below the head of the stop screw. An appropriate connector at the end of your wires or cable.

How I Designed This

The originator, tskauli did us a great service, and made his .scad file very well organized and commented. This allowed me, without any Open Scad experience to make some changes I desired.

Removed spring trenches; rerouted the wire tunneling; enlarged adjustment screw through hole; removed the small cut away on the knob.
The wire tunneling, as it was, I can see offered strain relief. But I wanted it to go straight out the back and allow more room for other changes. I think I might use a dab of hot glue or a 1/4" shrink tube collar, inside the wire well, for strain relief.
I then ported it to TinkerCAD (I know better how to use it) to finish my desired changes. See it there.
Use a concave and a convex feature to capture various spring sizes (with dia. 3-12mm).
Recess for back mounting screw
Add small guide collar to help ensure perpendicular mounting of the stop screw.
Added a bill (or toe) to the front of the base, to better avert tipping at front (when used portable without an extra base). And I think it's cute. I may draw eyes next to mine.
I also provided an option for one of the wires to come out early, so it could run along the bottom side of the arm. This also relieves having to pull out more wire in order to have the arm swung up when the stop screw is not in place.

Morse_Key