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howto:pcb_engraver

QuickCircuit PCB Engraver

Is a QuickCircuit device connected to an AMC2500 controller box (serial interface from factory.)

It has 2 axes of stepper controller motion, a high speed spindle and a neat solenoid to push the spindle head down on the workpiece (complete with a “foot” to hold the piece flat and adjust the cutting height.)

Materials

There's a box with the original QuickCircuit manual printed out in it (essential reading if only for the how to adjust section.) The PC has (did have?) the Windows QuickCircuit software installed on it, but this is a demo version that can't do isolation routing (ie it can't take a gerber PCB file and work out the router paths directly.)

Current Functionality

Angus & Adam did some experiments talking directly to the onboard controller. Angus managed to mill some boards this way, not the greatest workflow but OK.

Scripts: https://github.com/projectgus/amc2500/

Mailing list post about the experience: http://www.makehackvoid.com/pipermail/makers/2013-November/005961.html

Driving the machine with EMC2

This is an alternative design (by Alastair) to control the PCB engraver directly with LinuxCNC/EMC2 via a parallel port interface. Idea is to disconnect the controller's MCU from the optocouplers & buffers which interface it to the motor drivers & limit switches, and instead replace it with a parallel port from a PC running EMC2.

This is an Eagle project with the proposed interposer which will allow us to switch between the local MCU and the parallel port by moving jumpers: quickcircuit_emc_20110504.7z

Interposer Operation

The chips on the right of the schematic are dummies, and will contain pin headers to connect into the existing IC sockets.

The real chips are on the left of the schematic, and are connected to the dummy chips via jumper blocks (note: some lines are connected directly as we do not care about feeding/driving these signals from the PC). LEDs are connected to allow visual inspection of the lines to identify which lines perform which tasks under MCU control, so an appropriate mapping can be created for EMC2.

The single row jumpers are intended to be placed adjacent to their corresponding double row headers, to allow the signals to be sent/driven by the parallel port. JP3 goes next to JP2, and JP4 goes next to JP1.

Direct EMC2 Control

The Interposer PCB was too complex to mill out, so a revised version was made which only allows EMC2 control. The new simplified board uses SMD components (except for the DB25 connector and pin headers mating to the motherboard), has wider traces and does not try to squeeze traces between pins.

howto/pcb_engraver.txt · Last modified: 2014/07/15 00:09 by 118.209.159.39