The G3YUH Morse Key Project
 (Or how not to make a Morse Key)

This project really started a long time ago when I retired back in 1998 and rekindled my old love of homebrew Amateur Radio Equipment. I’ve built various radio related projects of all types since my school days, and recently got interested again in simple valve related equipment, Receivers and transmitters, the lead on from this was the purchase of a small collection of Morse keys, (well I think it’s small the wife doesn’t)

I like Morse keys, the small but intricate mechanism attracts the frustrated model engineer that lives inside me, I’m pretty well equipped for making Radio related projects having worked in Electronics all my life, and I have the knowledge that goes with it, but model engineering is for me a bit of a mystery. I know the basic principles from my schooldays in the metalwork classes, and can still clearly remember being boxed round the ears for starting up a lathe with the chuck key still in the chuck!  I have a few tools that one collects over the years for home maintenance, electric drill a pillar drill and odd tools like files and sheers etc but nothing so elaborate as a lathe or that sort of thing,
So it was with some sense of adventure when I decided my next project would be a Homebrew Morse Key, I’d seen homebrew Morse keys before usually made from a hacksaw blade and a few drawing pins, the premise being if you are an expert at Morse Code you can send on anything. Well I’m not an expert, and for me to send anything like readable code I need a decent key. My collection of keys and the use of them has shown me what is and what isn’t a nice feeling key, all that remained is to pick a first class key design that I could possibly make a working key from. So after much deliberation I thought I would make an attempt on the standard straight key set up used the world over by some of the very best key makers like Marconi, so this first attempt will be based on the Marconi 365 

I have ordered my materials and a knurling tool and having made a few sketches I’m about to embark on a voyage of discovery and no doubt a few damaged fingers on the way.
These are the materials I ordered to make a start, all 12inch lengths of,  1/8th Steel rod, 2BA studding, 1inch by 1/4inch flat brass, 1/2inch round brass, Two ball race bearings 1/2inch outer 1/8th inner, a couple of knobs and a knurling tool, total cost was £34 the knurling tool being the most expensive single item at £10 but it should be worth it if I continue to make a few keys :) 
After drawing a freehand sketch of the key I intended to build I started measuring a few keys in my collection and pictures of famous straight keys, to see if I could get an idea of a good balance of dimensions.
Then I decided, hasty as usual to make my first practical move, this was drilling and tapping a hole at what was to become the "Nose" of the key, 
It did not go smoothly, when I tried to screw in the studding it went quite tight in the thread I had made my tapping size slightly to small, One of the many problems I was going to have by mixing Imperial and metric sizes, I had decided on using Imperial as a bit of Flag waving nostalgia but in the end had to give in to Napoleon and so the key is now really an international project :) The main arm of the key is 6in by 1/2inch square, the adjusters are 2BA studding With ½ inch round brass heads and the bearing holders 1 inch by ¼ inch all brass. I had intended to only use the tools in my garage but I simply couldn’t work out a Way of knurling the adjuster heads without the use of a lathe, I could get a shallow Knurl by pushing the knurler against the round brass in my 

Pillar drill but in the end I gave in and wandered round to my next door neighbor and used his lathe to deepen the knurl, Then I drilled the the other holes in the arm for the contact adjuster and the spring tensioner

The tensioner is a mixture of ideas, It is a 2BA clearance hole with the Studding ground flat half way through so it can slide up and down, the adjuster nut on the top can raise or lower the studding, there is then a 3mm screw tapped into the side of the hole which meets the flat on the studding so when the spring tension is being adjusted the studding can’t turn, but can still easily travel up and down.

 
Next I started on the arm pivot bearing holders, these are just 1 inch by 1.5 inch brass plates with ½ inch holes drilled in to take the ball races, I shall have to slot these and fit screws to tighten the bearings,  then drill and tap the bottom to fit the bottom plate which will be the next job, so far this has taken all on of one Saturday, great fun so far and fingers still intact J time for Tea….
                              
Up bright and early on Sunday, and out in the garage for a bit more Morse key project, time to slot the bearing housings, tap the tightener screw holes and fit the bearings, the plan was to try and cut a slot with a diamond cutting blade fitted to my drill but it was hopeless and made a right mess of the first one, so the second one I cut with a hacksaw and sat with a flat file making a reasonable slot, it could have been better but after all it was a Homebrew project and I wanted to move on, next was fitting the bearings, somehow I always thought bearings should be a really tight fit, well that's wrong, maybe with large bearings but small ones tend to bind if they are to tight, at the time I didn't realize this and carried on drilling and tapping the bearing housing and grinding it to a snug fit all round.
In the picture left you ca see how it all fits together, everything is just balancing as there is no center bearing shaft and the knob is just sitting there unfixed, the idea being to give me an idea of how it will look when finished, The knob is obviously to low and the wrong shape and the shaft at the knob end to thick making the key look to heavy but generally speaking it was starting to take shape, the stone base again was a test to see what it looked like but I decided to use a hardwood base later, time to fit the bearing shaft and have a play with the movement. 
Here you can see it completed, after hours of struggle, after drilling and fitting the shaft and fitting everything together I found the movement of the key was tight, not to bad but bad enough to consider a complete strip down, and re bore the bearing holes, this is no easy task as the bearing were very tight in the holes and the shaft had to be tapped out of the bearings where it was set for life! also the tighteners were now in a different position and the clearance hole had to be enlarged to get the screws to locate properly. enough for today, start again Monday.
Time to take stock on Monday and have a play with the key, as now its is starting to look like a key, the movement is completely free with zero side movement which is a good start but still heavy at the back end, so I decided to lighten it by removing some brass, I cut it down with a hacksaw an 1/2 inch at a time fine finishing with a fine grindstone, testing it then removing some more brass until I got a nice balance, this wasn't easy as I was modifying the knob at the same time, adding a brass spacer to give a bit more height
Finally I got it right, or as close as I could get without the key being usable, fine tuning would come later, I fitted the return spring tightened everything up and gave it a bit of a polish to remove grease and a few light scratches, I can't decide yet whether to leave the machining marks on the bearing holders or not, as it is they look quite good, next job is to make the contacts that will fit into the base, I'm thinking of using old relay contacts soldered or brazed onto the brass studding but until I get the key mounted I'll have to wait.
Contacts are made and the whole body transferred onto a hardwood base, I had a few little problems trying to line everything up and I had to trim a bit of studding here and there, but it works, better than I ever expected at least comparable with the Kent key which design is very similar, not quite sure if its as good as the Marconi :) but very close, And so ends the great G3YUH Morse key project, I've learnt a great deal from this project, more so training myself to make accurate markings and cutting, my old metalwork teacher would have been proud of me
I shall call it the "Franklin" key in his memory  :)
Post Script. Now 14 months on I have made over 59 Morse keys of all types, and I've had great and learnt a great deal, refining my Metal working skills in the process, I have also extended by small garage workshop to include and old but very serviceable lathe, Pillar drill and fine cutting milling and knurling tools, you can see all my Homemade keys here,l HERE