Re: CNC Plasma Help

In a message dated 12/28/99 3:28:29 PM Hawaiian Standard Time,
xmas4lites@... writes:

<< From: Jay Hayes <xmas4lites@...>

I'll have to get back to you with the exact specs on the rack and pinion
drive components. (I'm not near the machine right
now.) Off the top of my head, I'd say the rack is 3/4 wide by 3/4 high and
maybe 10 or 12 pitch. The rack is attached along the
X axis so the teeth are on the side of the rack. The pinion that engages the
rack is between an inch and 1 1/4 in diameter. The
rack and pinion are positioned in this manner so the dirt will not collect
in between the teeth of the rack. The rack on the Y
axis is attached with the teeth pointing down for the same reason. The
pinions, encoders, gear reducers and servo motors are
attached to a plate that pivots on one point. A spring holds the pinion
against the rack when the drive is engaged. A toggle is
used to overcome the spring pressure to disengage the drive.

Each axis rides on one inch Thompson linear ways. Instead of linear
bearings that would quickly foul from all the grit that
plasma cutting generates, each axis rides on inch and a half sealed bearings
grouped in pairs that are each set at 90 degrees to
each other. This arrangement also promotes self cleaning.

The size of the motors that you will need will depend on how heavy you build
the gantry and how fast you need the cutting speed
to be. Overcoming inertia and top end speed are the biggest factors in
determining the size of the motors. My machine has a lot
of mass. It's built out of quater inch wall, 4 inch square tubing. It will
cut an area 72 x 126. I think the servos each usually
pull about 3 amps.

Jay Hayes
Weston, WV >>
Jay,
Any chance you got pictures on the web or something you can e-mail to me?
Thanks.
Peter