Re: rotary hand encoder wheels with detent

To add to the mud...

What divisions are common on metric commercial machines??

Also, I'm looking at the possibility of implementing a handwheel
with IndexerLPT, but the easiest approach (using 2 of the standard
input lines) would allow the possibility of missing steps at
higher rotational speeds. My guess, based on some of the
discussion here, is that this would be tolerable for many of the
same reasons a 36 position wheel would be an acceptable
alternative to a 100 position wheel. When it is really critical,
you'll be going slowly, or looking at the position readout.

Thoughts?

Carlos Guillermo
VERVE Engineering & Design

-----Original Message-----
From: Alan Marconett KM6VV [mailto:KM6VV@...]
Sent: Monday, February 18, 2002 1:33 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
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


audiomaker2000 wrote:

>
> Hi Alan,
> Too many.
> Your jog increments should be...
>
> .010
> .001
> .0005
> .0001
>
> Anything less is silly and anything more is dangerous. You don't

want

> to be able to travel 20 inches with a revolution of your wheel.
> What is done instead is having a jog "continuous" where you hold

an

> axis jog key and it keeps moving at the set jog feedrate. This

allows

> you to move larger distances without spinning the wheel. Imagine

the

> acceleration of a jog wheel you could spin revolution in .1

seconds

> when set at .1" per increment (100 increments would equal 10

inches

> per revolution). That's un-necessary, un-doable by most motors,

and

> dangerous.
>
> Sean
>