[Elecraft] Lighter spring pressure for the KXPD3

[Art Nienhouse]

Hi Buck

Lighter spring pressure how I did it.

I found a longer spring  I cut off the ends where the coil bind winding 
are, cut it just short of installed length same as the (original) spring 
length.
Next I closed one end a bit to fit tight on the threads of the screw 
then Installed the spring by screwing in on the threads holding it in 
place. Install it on the other paddle arm screw before putting the arms 
in place, squeezing the paddle arms together dropping the arms on the pins.

I reassembled the paddle tried it for feel on the second try the spring 
feels right with a lighter closure pressure. I cut the spring a bit 
short in length then pulled the spring apart to stretch it to the proper 
length same as the one that came with the key.
I think these keys could be supplied with several springs so the closure 
pressure could be set to a preference by the operator.
Shims could be supplied to add pressure to an existing spring. This 
changed the feel making the key usable for me.

Thinking of how I could make the spring tension adjustable I would do this.

Find the right length allen screw ( no head ) the length to be 
determined for final build.

Next I would find a spring with a bigger diameter with less turns per 
length, the end to fit a shoulder washer.

Turn a washer or find a washer shaped with a shoulder so the inside 
could be threaded to fit the allen and the out side  diameter would hold 
the spring the shoulder of the washer would be inside the spring.

Install this on the allen with washer and spring about half way along 
the length to be timed out when installed the allen would be flush with 
the out side of the paddle arm, when the final dimensions are set 
Loctite thread locker would hold this washer in place so it could not move.

Last install it from the inside out now this lighter spring with less 
turns bigger diameter would be more sensitive to closing (adding) 
pressure against the two paddle arms now turning the allen screw from 
the outside will adjust the arm closing pressure.

Several springs /shim washers might be the way to go.

Regards
Art
ka9zap