I tried to send pics but they got hung up in the Listmom's approval
list. I'll try later to attach them or something.
Here is screen grab of the vid I made the other day that shows the
machine, mostly, and you can see the old laptop to the right that
drives the controller (which is under that switch box). The whole
thing is sorta bodged but it works pretty well. I keep saying I am
going to get it cleaned up and organized but....
The bottom pic shows a bevel bit engraving text outlines -- you can
do inside the lines (pocketing), on the lines, or outside the lines,
whatever you want.
I use a free program called Cambam to do designs, then create gcode
from the designs (gcode are the commands that tell the machine where
to go in 2.5D), then that gets loaded into a program called Mach3
that actually sends the gcode commands out the parallel port to the
stepper motor controller and drives them to turn the lead screws
which moves the router around.
On the pic you can see the screws and slides for the Y and Z axes,
the whole gantry slides on 1/2" rods that are under the table. You
can see one stepper in the back that drives the Y axis. I scavenged
those out of old Laserjet III printers, they are quite strong and
have 1.8deg per step, so 200 steps per rev, and the lead screws are
10 pitch, so that gets me down to 0.0005in resolution which is
pretty good, though there is more slop in the system than that, but
not really noticeable.
Note that if you wanted to build one of these on the cheap, you can
use some common materials and driver boards and software, and a
Dremel -- you could probably get one going for about $100, maybe
less if you worked at it. I probably have about $500 in this one,
the precision slides, lead screws, and bearings and nuts were kinda
pricey but give it some good performance. The driver board was a
$100 kit. I have a power supply I got from a surplus shop, it came
out of an old film developer and is pretty cool. You can build one
for not much too using common components.
I have a single axis driver I built with an Arduino, I think it will
do 2 axes, and I could drive 2 boards with the Arduino, so that is
pretty cheap stuff. I built a test rig from some threaded rod and
nuts and some wood scrap, driving it with an old stepper motor from
a printer or scanner or something, and a power supply from an old
Laserjet. Even with the random bits I had laying around, the thing
has pretty good repeatable accuracy.
I think a linux program has been ported to a Raspberry Pi, a $30
computer, so that eliminates the need for a laptop or desktop
machine, just hook that to your stepper drivers and you are off and
running. The laptop I am using was my daughter's old HS machine, it
died a year ago so I found one on eBay for $29 just like it, popped
the HD in and up and running again. Any old desktop would do too,
long as it has a parallel port for Mach3.
I could probably build the frame out of metal extrusions but not
sure what it would do for me at this point for things I use it for.
I have actually done some really nice things with it, a very cool
adjunct to classical woodworking.
If anyone is interested I could give you a straightforward tutorial
on how to get up and going -- there are lots of kits and plans out
there for machines, from really cheap to really nice, I sorta just
made one similar to a kit a friend bought, did not take long once I
got the parts together.
--R
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
