Re: rotary hand encoder wheels with detent

Hi Mike,

The problem with "keyboard jogs" is if the "repeat" function of the
keyboard is used, it repeats at a rate that is not very useable.
Hopefully the controller program "traps" the raw keydown and keyup
codes from the keyboard, and does not rely on the "getch()" type of
keyboard function. This way, a key that is still down, can be used to
"stretch" a jog into a continuous move.

Alan KM6VV


Mike Snodgrass wrote:

>
> This may seem a little "Micky Mouse" but some time ago I built a device to
> send different keystrokes to the computer. At the time I was using an old
> XT with limited resourses, an Dan Cam 3D. I found an old keyboard that
> had hard printed cincuits in it along with good ole click keys. I soldered
> small wires to all the keys that I thought that I would use and ran one wire
> to ground.. Then I ran
> all wires to a D-shell connector on the back of the keyboard. From that I
> could send keystrokes from what
> -ever device I chose. I am now starting to use Mastercam5, which also will
> let you use the keyboard to jog. I am considering getting the old keyboard
> out and dusting it off and putting it back to work. Hope this is an option
> for you.
>
> ----- Original Message -----
> From: "Alan Marconett KM6VV" <KM6VV@...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Monday, February 18, 2002 11:33 AM
> Subject: [CAD_CAM_EDM_DRO] Re: rotary hand encoder wheels with detent
>
> > Hi Sean,
> >
> > I wondered about that. .000125 results in a single step, whereas .0001
> > is not. Perhaps .00025 would be better, two 1/2 steps (Sherline).
> >
> > I see you point about limiting the travel on a full spin, but as I
> > currently also set a jog rate and use an incremental encoder, spinning
> > the knob fast will "loose" the handwheel steps. Using a DRO chip would
> > "save" these steps, something I'm intending to experiment with.
> >
> > When using the keyboard keys to jog, holding down a key will continue
> > the jog. With the encoder and a DRO chip, something similar could be
> > done.
> >
> > I have observed that with larger jog sizes, more jog rate is
> > appropriate, and what I'd really like to do is make the rate dependent
> > on the distance to be traveled. The rate would have to map at both
> > ends. Slow enough at the low end such that single steps could be
> > traveled for "touching off", and fast at the larger end so that motion
> > would be more continuous.
> >
> > Alan KM6VV