Re: rotary hand encoder wheels with detent

Hi Fred,

It does sound a little overwhelming. And add to that the desire to have
a faster jog rate at the larger distances. Seems they should be tied
together. The keyboard jog IS convenient. And with MDI, there is less
need for jogs as well.

I have never really used a feed override, MaxNC has a limited override
facility, but it is nothing like what the "big machines" you and others
have discussed have. MaxNC's requires one to pause the move, which I
could do, but I think I'll try to implement a "bump" up or down of rate
(I use a rate table) while the axis is moving. I have a 4 channel D/A
module that can be read from a second LPT port, although it is a serial
device, and would take time to read. It could be connected to a 10-turn
pot, and would therefore have a "0" point, and could be easily scaled.
How are feed overrides typically implemented?

Best regards,

Alan KM6VV


imserv1 wrote:

>
> --- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > Hi Fred,
> >
> > I've been trying these step sizes, too many?
> >
> > 0.200
> > 0.100
> > 0.050
> > 0.020
> > 0.010
> > 0.005
> > 0.002
> > 0.001
> > 0.0005
> > 0.00025
> > 0.000125
> >
> > Although the Sherline and stepper motion hardware isn't accurate to
> the
> > smallest step size, it seems necessary if one wants to creep up to a
> > surface, to set a zero on a part.
>
> Not a problem from the development or "play" viewpoint. I suspect
> that once you get it working and actually use it that you will only
> want the .002 and .001.
>
> The Stick-Slip on the ways and stepper granularity will be a problem
> with small increments. You will turn the knob and nothing will
> happen for a while every time you change direction (backlash).
>
> For larger distances you will probably want to use the controller jog
> and push in a button.
>
> Are you doing anything with % Feed rate override? Have you given it
> any thought? Some of the controller software has this built in as a
> key press adjustment during program operation, some doesn't seem to
> have any provisions to adjust the feed while the program is running.
>
> Best Regards, Fred Smith- IMService