On 7/20/2014 3:31 PM, gareth wrote:
"vu2nan" wrote in message
...

gareth;822016 Wrote:
"vu2nan" wrote in message
...-
gareth;821995 Wrote:-
A straight Morse key has a fulcrum away from you, but your wrist
articulates in front of the key, in a mirror image of that of the key.
Therefore, your wrist is constrained to follow an unnatural arc
when keying.
Have there been any mechanical designs published so that the
keying arc is in the same sense as the wrist arc?
(cf. Watts' parallel motion, perhaps?)-

How about keeping the key turned 180° (facing away from you)?!
-

That thought did occur to me in bed last night. The main difficulty
would be
in needing a special-purpose table with an indentation...............by
having a
downward right angle bend for the paddles, you keyed
horizontally.

Hi OM Gareth.

Or the key should be below the table-top with only the knob projecting
out!


Yes, the knob protrudes, but the skirt of the knob is flush.

I can't see how the arc of the key is important. The key only moves a
tiny amount and the arc is very small with a miniscule perpendicular
movement. The issue of the key being above the table is a different
matter. This could be handled without making holes in the table.

A good key only moves a tiny amount. The key can be curved so the
actual key can be just a small paddle a few mm above the table top. Or
the user can use a wrist rest to elevate the wrist.

====O=====+
/ \ |
/ \ +----- -- Key "knob"
==================== Table

Does this make sense?

--

Rick

"rickman" wrote in message
...
On 7/20/2014 3:31 PM, gareth wrote:
"vu2nan" wrote in message
...
gareth;822016 Wrote:
"vu2nan" wrote in message
...-
gareth;821995 Wrote:-
A straight Morse key has a fulcrum away from you, but your wrist
articulates in front of the key, in a mirror image of that of the key.
Therefore, your wrist is constrained to follow an unnatural arc
when keying.
Have there been any mechanical designs published so that the
keying arc is in the same sense as the wrist arc?
(cf. Watts' parallel motion, perhaps?)-
How about keeping the key turned 180° (facing away from you)?!
That thought did occur to me in bed last night. The main difficulty
would be
in needing a special-purpose table with an indentation...............by
having a
downward right angle bend for the paddles, you keyed
horizontally.
Hi OM Gareth.
Or the key should be below the table-top with only the knob projecting
out!
Yes, the knob protrudes, but the skirt of the knob is flush.

I can't see how the arc of the key is important.

Then you have not grasped the point of the discussion.

On 7/21/2014 6:26 PM, gareth wrote:
"rickman" wrote in message
...
On 7/20/2014 3:31 PM, gareth wrote:
"vu2nan" wrote in message
...
gareth;822016 Wrote:
"vu2nan" wrote in message
...-
gareth;821995 Wrote:-
A straight Morse key has a fulcrum away from you, but your wrist
articulates in front of the key, in a mirror image of that of the key.
Therefore, your wrist is constrained to follow an unnatural arc
when keying.
Have there been any mechanical designs published so that the
keying arc is in the same sense as the wrist arc?
(cf. Watts' parallel motion, perhaps?)-
How about keeping the key turned 180° (facing away from you)?!
That thought did occur to me in bed last night. The main difficulty
would be
in needing a special-purpose table with an indentation...............by
having a
downward right angle bend for the paddles, you keyed
horizontally.
Hi OM Gareth.
Or the key should be below the table-top with only the knob projecting
out!
Yes, the knob protrudes, but the skirt of the knob is flush.

I can't see how the arc of the key is important.

Then you have not grasped the point of the discussion.

Gareth, I typed a fair amount explaining my rational (which you
snipped). If all you can say is, "you have not grasped...", then you
are a pretty poor conversationalist. Someone else made the same point
that the range of motion is so small that the center of motion is not
really very important.
Key Arm Hand
--o------------------------) (-------------------------o--

With a very small range of movement at the point of contact there is no
real problem with stress.

One thing I believe has not been pointed out is that the fingers are
part of the link and their multiple joints act to isolate the wrist from
the exact motion of the button. In other words, you are discussing a
problem that doesn't exist in regards to the arc of the button.
|------- Finger ------|--Hand--|
--o--------------------) (------o-------o-------o--------o--


If you want to discuss this, then please don't be condescending.
Instead, say something useful please.

--

Rick

"rickman" wrote in message
...
On 7/21/2014 6:26 PM, gareth wrote:
"rickman" wrote in message
...
Yes, the knob protrudes, but the skirt of the knob is flush.

I can't see how the arc of the key is important.

Then you have not grasped the point of the discussion.

Gareth, I typed a fair amount explaining my rational (which you snipped).

Because it added nothing further.

On 7/22/2014 2:03 AM, gareth wrote:
"rickman" wrote in message
...
On 7/21/2014 6:26 PM, gareth wrote:
"rickman" wrote in message
...
Yes, the knob protrudes, but the skirt of the knob is flush.

I can't see how the arc of the key is important.

Then you have not grasped the point of the discussion.

Gareth, I typed a fair amount explaining my rational (which you snipped).

Because it added nothing further.

Ok, when you wish to have a discussion, let me know.

--

Rick

"rickman" wrote in message
...
On 7/22/2014 2:03 AM, gareth wrote:
"rickman" wrote in message
...
On 7/21/2014 6:26 PM, gareth wrote:
"rickman" wrote in message
...
Yes, the knob protrudes, but the skirt of the knob is flush.
I can't see how the arc of the key is important.
Then you have not grasped the point of the discussion.
Gareth, I typed a fair amount explaining my rational (which you
snipped).
Because it added nothing further.

Ok, when you wish to have a discussion, let me know.

Well, I was. But you were off on a different tack.

On 7/22/2014 4:20 AM, gareth wrote:
"rickman" wrote in message
...
On 7/22/2014 2:03 AM, gareth wrote:
"rickman" wrote in message
...
On 7/21/2014 6:26 PM, gareth wrote:
"rickman" wrote in message
...
Yes, the knob protrudes, but the skirt of the knob is flush.
I can't see how the arc of the key is important.
Then you have not grasped the point of the discussion.
Gareth, I typed a fair amount explaining my rational (which you
snipped).
Because it added nothing further.

Ok, when you wish to have a discussion, let me know.

Well, I was. But you were off on a different tack.

I am beginning to understand why you get a lot of flack here.

If you aren't interested in discussing the topic, why do you keep
responding? I am beginning to think you truly can't help yourself.
Here is another chance to discuss the topic.

The movement of the end of the finger along the arc of the key does not
need to be the same curve as the movement of the wrist because the
finger provides compliance by bending at the other three joints, plus,
the difference of movement of the two arcs is so miniscule, that it does
not cause a problem in the first place.

My father operated a telegraph key in his job as well as most of the
people he worked with. None of them ever reported any sort of
repetitive motion injury.

BTW, I have the brass key he used.

--

Rick