Re: XYYZ Gantry

Hi Peter,
First of all both the Y and Y are wired together. They
are not wired to separate outputs of the controler in most cases. See
one at:
http://www.geocities.com/luberth.geo/plotter/plotter.htm

You emailed asking me about my glass etcher. Here is what I
learned. If you just want to add a signature or small flowers to the
corner of a mirror, it can be done! If you expect to put a portrait
on the glass stop right now!
Glass is very hard and hobby machines are too slow. A simple
drawing from Corel saved as a DXF converted into Gcode will run over
an hour. A Dremel diamond covered bit will not hold up that long!
You asked me about GLASSMAN. Glassman was a square base with
the center cut out. It looks just like the plotter on the above link.
Glassman sits up on four suction cups above the glass. The cutting
tool goes down past the opening to hit the glass. The Z-axis is
lowered down onto the glass. The Z assemble can float a little, there
is a spring pulling down on the Z-axis.
I got commissioned by a so called friend to build a CNC
machine that cuts paper rolls for crank organs. My job was to build
the electronics for the machine. I sent parts of Glassman as a demo
to prove my electronics work. The so called friend never sent back
my parts.
My friends own a glass company. They send out the glass
etching work. The etching is done by a man in a spacesuit in a sealed
room. Glass beads are shot at the glass. The reverse of the design is
put on the glass with tape. The man is able to adjust for variations
in air pressure. He only charges $100 to do a store front!
I think it is possible to put grit on the glass and design
a tool that moves over the glass pushing down the grit and causing
a pattern to be cut. Have fun!

John

--- In CAD_CAM_EDM_DRO@y..., Peter Chen <cadcamcenter@y...> wrote:
> XYYZ GANTRY
>
> Good morning,
>
> Asking for opinions on XYYZ gantry. I believe this
> configuration will involve having 2 lead/ballscrew and
> 2 stepper motors for the Y axis. Suppose one of the
> stepper on the y axis lose step. Does this mean that
> the x and y axis will no longer be perpendicular to
> each other? With this arrangement how does one ensure
> squareness?
>
> Thanks
>
>
> Peter
>
>
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