Re: Jog wheel

[Ray Henry <rehenry-at-up.net>]

On Monday 03 June 2002 10:58, you wrote:
> > I can certainly understand where you're coming from here.  Let's not let
> > this minor difference in imagined function stall out the process of really
> > making one of these that works.  Let's drawn up the specs for one of 
> >these and throw it into the code writing stage.
> >
> > I'm not sure that the Tcl/Tk code level is the appropriate one for this
>> but
> > we could easily prototype it there and then translate it when we have it
> > working the way we think it should.
> >
> > If we need cheap quadrature, one of those oven temp pulsers should do the
> > job. but as Paul points out, mouse guts should do it also.  I seem to
> > remember that he put started some code read a second mouse connected to a
> > serial port.
> >
> > Ray
>
> Hi Ray,
>
>
> I guess first decision needs to be if it will have any type of counter
> such as the LS7166, or if the encoder will be wired directly to one
> of the ports. How many encoders, one for each axis or just 1 with
> a switch to toggle the axis? What port, serial (would require a counter)
> parallel, game?
>
> I like the idea of having pushbuttons, as an axis select/enable
> hold the X button down and spin the wheel to move that axis, prevents
> accidential bumping and sending the axis off on 3 clicks at 1". If
> it was layed out right, one hand operation of the enable button and
> jog wheel would work. Or 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 forsee
> me wanting to move Y and having it set to X and spinning the
> wheel. Others may not like the enable concept, I'm just tossing
> out ideas here.
>
> I have a couple of shaft encoders, some old mice and other stuff
> around here, but what would be the best is a 25CPR encoder with
> 100 clicks per revolution. That would probably need to be made by
> us. Digikey has some 25 CPR encoders at
> http://info.digikey.com/T022/V2/0742.pdf bottom left of the page.
> $21.00 in quantities of 10, $30.00 for 1
>
> Bill

Bill

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.  

Such an interface in iosh should allow us to set up chips, pic's, stamps, or 
tigers or whatever kind of outboard device we want to hang on there.  Then we 
could write scripts that use iosh to test those i/o devices.  Many of these 
intelligent devices have rs232 interfaces set up.

You wrote
> 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.

Hope this helps.

Ray