LasaurShield - nortd/lasersaur GitHub Wiki
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The LasaurShield connects Arduino, stepper drivers, and wires. In addition it also implements a strictly hardwired safety subsystem (logic gates). The laser is forced off when any of the following occurs: door opens, chiller off or malfunctions, a limit switch triggers.
- size is 80x70mm (3.15x2.76")
- double layer pcb
- Immersion Silver (ROHS)
- Also see the Lasersaur wiring diagram
The relevant parts from the BOM are:
- 1x 36 pin header 2.54mm pitch 538-22-28-4360
- 2x nand logic ICs 863-MC74AC20NG
- 7x resistor 10 KOhm 271-10K-RC
- 5x resistor 100 Ohm 271-100-RC
- 10x screw terminal, 2.54mm pitch 651-1725672
- 2x screw terminal, 3.5mm pitch 1984714
- 1x screw terminal, 5.08mm pitch 571-2828414
- 1x resistor 20 KOhm 271-20K-RC
- 1x resistor 6.5 KOhm 271-6.49K-RC
The board uses two resistors to set the maximum current of the stepper motors. If your motors or drivers differ from the latest BOM make sure you use the correct resistors (named x-current, y-current; some boards also say x-set and y-set).
| x-current-set | y-current-set | |
| Nanotec/G203V (standard as of v12.02) | 6.5 KOhm (271-6.49K-RC) | 20 KOhm (271-20K-RC) |
| Lin Engineering/G203V | 12.7 KOhm (271-12.7K-RC) | 20 KOhm (271-20K-RC) |
| Lin Engineering/G251X | 1.5 KOhm (271-1.5K-RC) | 2.1 KOhm (271-2.1K-RC) |
| stepper motor | x-terminal | y-terminal |
| Lin Engineering WO-4118S-01 | black -> A; green -> /A; red -> B; blue -> /B | |
| Lin Engineering WO-5718M-02ED | blue-white -> A; red -> /A; green-white -> B; black -> /B; blue -> red-white; green -> black-white | |
| Nanotec ST4118M1206-A | yellow -> A; red -> /A; brown -> B; orange -> /B | |
| Nanotec ST5918M3008-B | black -> A; green -> /A; red -> B; blue -> /B; red-white -> blue-white; black-white -> green-white |
The LasaurShield has a couple of IO-pins to control air and nitrogen valves. They can be controlled directly via G-Code (M7, M8, M9). The air valve should be connected to A4 and is turned high with M7. Nitrogen should be connected to A5 and is turned high with M8. G-code M9 turns both low. To switch a solenoid valve please use a 5V micro-relay that draws less than 40mA.
NOTE: Unfortunately some of the v12.02 boards have incorrect or missing labels for the air assist pins. The following are the correct pin outs. When unsure about this drop us a line on the mailing list.
