Re: Jog wheel

["William Scalione" <scalion-at-dellepro.com>]

>
> I'm way out of my league here and others are welcome to trash this idea
but
> it seems to me that rs232 serial ports are going to be around for a while
> with linux.  If we write the code to connect a serial port into iosh we
> should be able to make almost any kind of device we want out there and
> connect it with a rather simple cable.  USB powered would be easier but we
> can hang a little connector alongside the db9 to carry power to the
device.

US Digital has a quadrature to RS232 adapter, but it's $125.00 each.
Probably
just a LS7166 chip, a uart, max232, and some glue logic. If someone can come
up
with a circuit, I will hardwire a few together and send them off to you
software
experts. They also have a USB model that will do 4 encoders and some digital
inputs, but it's pricey. Then there is also the Dan Mauch Encoder board that
would
work if you are not using it for encoder feedback, but that is ISA bus.
Probably
not the best for future expansion.


> > a single button to step through the axis
> > select and one to enable. The axis select/enable button would
> > be a way of ensuring this is the axis I want to move.
>
> I like this idea if the enable could be under or alongside one of the
fingers
> that you use to hold the device.  One nightmare of mine used a 1" or so
> diameter tube about 4 inches long.  The wire would exit one end and the
> handwheel would cover the other end.  Most of the handwheel would be
covered
> around the outer edge so that you could thumb it from one side but not run
> the wheel on your arm or leg.  The top of the wheel would have a
depression
> so that you could spin it with one finger of your other hand.  That way
you
> could use it as either a traditional pendent, or one hand could hold the
> cylinder and thumb the wheel slowly while your other hand slid a paper
that
> you are using as a gage to touch off a part.
>
> I went looking once for small 100 tooth gears that I could use for a
detent
> but couldn't find any.  But if we turn out the knobs ourselves from AL we
> should be able to center drill or mill100 detents around the outer edge of
> the bottom and use a spring and ball from below.  Writing a g-code program
to
> do this would be a good task for CP-1.

I did the same today, and found some NEMA 17 stepper motors with 3.6 degree
per step. None with dual shafts to mount an encoder to the back side, and
probably
not much detent torque (is that the proper term?) either. But if you took
the rotor out
would it have 100 teeth on it?