Re: joystick control two axis stage

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Greg McCreight"
<gregmc@w...> wrote:

> Hello group A cnc type question I hope not off topic. We are

building up a video

> measurement system, I have a X Y stage with

stepper motors about

> 100 0z in size (not marked) The wires are

cut and the controller is gone

> I would like to set up a joystick ( stand

alone )system that would allow us

> to jog at a high and low speed does anyone

know of a kit or instructions

> at a practical cost for retrofitting or using

the origional stepper motors ?

> Maybe I am way off as I only see joystick

controlled tables on real

> expensive systems but would like to give it

a shot. If you guys say

> no way I will go regular cnc route and use

the keyboard to jog it will

> just take longer ! Thanks for any help.
> The old clockmaker
> Greg McCreight
>

Go to the DIY-CNC Group /Files/Circuits. There is a full two axis
wide range step/direction circuit that uses a joystick for both speed
and direction feedback. THe circuit features three ranges of pulse
frequencies using a rotary switch and has adjustable accel and
deaccel on each axis. Also there is a circuit showing 1/2 half of
the above for one axis. I originally designed it for using my mill
in manual mode but then Art added joystick interface to his software
so the need went away. It would still make a good stepper based etch-
a-sketch project! I used the chips in the design because of their
wide range VCO capabilities and linear frequency output with voltage
input. Basic 555 circuits have smaller dynamic range and are non-
linear without adding external active components.

You will probably want to remove the relays that allowed the joystick
trigger to switch the step and direction source from automatic
(computer) to manual. The components are cheap off the shelf parts
mostly CMOS 4000 series chips. Drop me a line off-list for specific
questions.

Tom C