Handwheel & Joystick

Well, here is a short mix of topics:

1. EMC : ( Fred )

There is so many different machines and needs, - it's not possible
to satisfy every need. The $9.99 joystick option - is interesting
! My question is, why not make it available ? I sure would like
if there could be room for a "scrap" directory on the website. A
small note about what it is, if it lacks comments. These small
software collections, is of great value - you don't have to reinvent
the wheel - and many times you can use it it quit different
contexts. Most of the time, - you just want to test an idea, or a
setup, quick and dirty. Often this can create new and very good
ideas.

2. Hand wheel: ( Fred )

I had the same questions about when I suggested this for the
manufactor. There is several ways to do this, - and I will just
mention one:
You just use it in manual mode, - and take the input from the hand
wheel as the encoder feedback ( toggle switches to select axis ).
This will offset your actual position, - but it doesn't matter. If
it does, save the value some place. When you start a program, this
will be your new zero position. You will only need a very slow
count rate on the hand wheel, the error loop gain would not have
any problem with it.
I used it to center a tool to a punch mark, then started the
program. It could be nice to sample positions too, like for a tool
changer, or other stuff. Maybe even output these values in a
readable file format -> into a CAD package again. ( digitizing ) -
or G-code.

( ? you could also have an external mux, and steal the motor
encoder, - an option that may work in some situations. Such a mux
could also have step/dir output. - i.e. you could have a handwheel
for step motors, without doing any modifications to the program. ? )

( .. or what about using a serial port ? Or game port ? I am just
thinking of expanding input ports for non stg users. A handwheel
could be great. )

3. Joystick:

I thought of using analog ones, and use the ADC on the stg board. I
was thinking of a general RT-module, and I could use these channels
for reading spindle rpm, pressure, what ever. I noticed a lot of
worry about it from others, - and I do understand this very well.
Don't try to incorporate too many options in the general setup. It
may just mess things up for people, - but I would favor a *scratch*
directory. Some of the contents did not have to be workable
programs, just rough sketches and ideas. Sure the more meat it has,
the better, but in many cases even rough sketches to an application,
is better than none.

(Dan) : " .. original game port is junk.. " I don't know, it might
work ok with RTLinux. It is a crude ADC ( timer ) - but it could be
useful. You could easy use this for monitoring oil pressure, rpm,
etc. - or a for feed rate over ride. If you have only steppers on
par ports, this interface could be very nice, - encoder input,
feedrate, switches, - you don't have to buy a special io card.

4. IO:

In the case of handwheel, and other stuff, you need to enable
switches as digital io. As I have not been able to assemble a
machine setup yet, I haven't looked into it, but I would use the stg
board for this.


5. CAF: ( Ian, - et al )

I just downloaded Rhino demo, and I will check up the other stuff,
and yes - you are right about the objects and stuff. I was thinking
of a much easier application to use. I just bursted out some ideas
:-) But, let us keep to it for a moment, - the parts you pick up,
could just pop up an input window - diameter please: , length : ,
etc. And it snaps on the centerline. You could also have a roller
bearing icon, - just enter the size, and the computer enters what
needed for the rest. You don't have to have any drawing
environment. I thought more of something you could do on the
"floor", on the machine center. Not something you had to fire up a
CAD program package to use, and it would produce the G-code direct.
This desktop could mimic your machine center, as where tool pockets
are placed. Do the hole thing.

I speak out of ignorance - I have not been working at a machine
center, and know little about it, - but the way I see it, there is
some trouble with CNC. Often you could do minor jobs manually, -
but a CNC machine will not give away the control that easy :-), so
I was thinking of some sort of entering programs, in a more easy -
on the fly - environment.


6. NURBS

Ok, Rhino uses this. What packages are great with solids ?

NURBS looks good for 3D, but not so good for mechanical parts ?

( it will take some time before I understand what rhino can do )




//ARNE