Lighter spring pressure for the KXPD3

[Arthur 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
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[Buck - k4ia]

Good ideas.  I hadn't tried to take the paddles apart yet.

Maybe I'll send it off to Pierro Begali and see what he would design.  
Probably end up with paddles that cost as much as the rig - but they
would be beautiful!

Buck
k4ia

On 7/16/2012 7:18 PM, Art Nienhouse wrote:

> 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
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Please help support this email list: http://www.qsl.net/donate.html