I have been thinking about making a magnetic straight key for some time... as usual, other things got in the way, and the project stalled !..recently, it was brought to mind again.
Magnets have been used quite extensively on Paddle Keys.. but the incidence of straight keys using magnets instead of a tension spring is much rarer. Although there are some very nicely engineered keys on the market for a lot of money.
This project was, from the start, going to be "cheap and cheeerful"... I have acquired lots of rubbish from previous projects, and elsewhere, so my challenge was to make a magnetic straight key with what I had available, without resorting to spending any money !>
The concept is simple, but the actual carrying it forward, caused a lot of problems to be solved "on the fly" so to speak.. for example.... the magnets... you need to find the "sweet spot" where they are "just" opposing each other... and measure that distance.... this gives the approximate height of the rocker arm... but it `s not simple trying to keep two magnets apart ! especially those from an old hard drive and some "near earth" types. They have a mind of their own and boy, do they jump !
Using an old morse key base, solved that problem ! the next was to find that "sweet spot"in real time and space !
.
Using the old key base... I found some wood , cut it into strips, and messed around with that, eventually finding "about the right" height for the rocker arm
The rest, they say, is simple... find something to support the rocker, drill a few holes in (hopefully) the right places, and put all your bits together.
You can see the result in the pics and the video...
here is a list of the "bits" and what they are doing
Rocker arm supports... these are two clothes rail supports from a DIY job a few years back...
Inside the cups ( 20mm dia) are two 19 mm dia ball races from another job... to make them fit snugly... I used strips of Masking Tape, on the outer edge until they just fitted nice and tight.. no glue ! ! .
This
presented another problem... as there was no "continuous" metal
connection to the support, therefore no "continuity" for the "return" to
make the key work!.. so I fashioned a brass strip into a "brush" on the
brass rocker cross member, and back to the metal support!
The rocker arm is a short length of square acryllic tube from another job ! .
Another
" problem " how to make the contact between the rocker and the base to
complete the full continuity circuit, to make it work... solution , a
long piece of copper wire. ( flattened at the end to squeeze between the
plastic and the alluminium extender! .. ( also had to flatten it a bit
to get the brass rod through! )
Under the black "dome" is some broken pieces of a magnet from a hard drive !.
the black dome, is a cap from something or other, that just happend to be around. to make that fit I used another of the 19mm bearings with a bolt through and the magnets sitting on top.. the black dome then push fitted over the whole lot... Neat ? huh?
The knob is from another key that I had a long time ago.. all that was left was the knob ! ... the "spark guard" disc is one from a "Bulk Purchase" of 10 when I needed only one ! .
the "floating magnet" is a "rare earth" type.. araldited on to the head of a brass bolt.... to make the "grip" on the top.. I used the outer ring from a TV coax plug, with a large nut underneath, and a dome nut on the top...
Same thing for the rear Gap adjuster. ...
The base has been kicking around the shed for some time ... so all in all, pretty cheap... and , hopefully, as you can see, not too shabby to look at !...
I wired it up, and plugged it in to my "linear" connection box (where my other 17 straight keys are attached to my Laptop) and gave it a go..
Quite pleased and surprised at how well it works ! ..
As promised, ... It`s not quality engineering....but it does work .! .
Here is a short video of it in action on CWCOM ...
CLICK THE [ ] Bottom right corner !
to show full screen
And for those "naysayers" who think that CWCOM does not work properly, because it is "no longer supported".. has not had any updates... and is not "open source".... here is proof that IT DOES WORK....
A video of a LIVE QSO on line.....
(this is working, using Linux Mint 20, with WINE installed, to enable Windows "type" programs to run on a Linux Machine.)
CWCOM Also works on MAC Machines....
(see relevant pages on the blog https://morsepower.blogspot.com/
CLICK THE [ ] Bottom right corner !
to show full screen
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