"Morris Dovey" wrote

Snip of some very good advice

It would not be difficult to move your sliding jig with one or a pair
of micro-steppers and set up the jig to clamp while in motion and
release at extremes of movement. That would allow the operator to
drop the block into the jig and press a pair of buttons (one for each
hand), then reach for the next block while the cut is being made. You
should be able to feed the block past the cutter at 3-4 in/sec
(180-240 ft/min). Once the cut block has been dropped, the jig can be
retrieved at a still higher speed. You'd need a PC (an old, recycled
386 would probably do) and a stepper controller to drive the motors.
Using steppers makes it easy to control feed speed and
acceleration/deceleration of the fixture.

Hey Morris,

This job is easily handled by a servo motor system. The one I'm thinking
about is a stepper motor with an integral controller. This controller can be
PC controlled, or you can program it to perform the very functions you
describe. With four digital input/output lines, and one analog input line,
you can (a) start sequence with two switches in series. This drops a shield,
forces a clamp to close, start the spindle, and after a brief (programmed)
delay, starts moving. When it hits the end-limit switch, it shuts off the
spindle, releases the clamp (allowing the part to drop), and after another
brief (programmed) delay, returns the carriage to the home position (set by
the "home" switch). The analog input port can be used to set the travel
speed, and you have the last output to either serve as a clamp release, or
other function you may desire.

I used 3-stack 34 size motors from Intelligent Motion Systems
(http://www.imshome.com/mdriveplus_overview.html) for the assembly line
battery tester; I was moving 45-60 pounds of fixtures on two axis and needed
the torque. We used acme screw rod and nut to move, and used turned, ground,
polished rod on linear bearings for low friction directional control.

Hope this helps ... with this approach, it's more mechanical than
electrical. You will, of course, have to provide a power supply for the
motor, and will need an RS-422/485 interface (available from IMS as well) to
program and/or control the motor. Nice thing about the 422 comms, you can
daisychain a pile of motors on one comms line (I had 14 steppers running at
once in direct comms mode with no issues).

Regards,



Rick