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Version 0.4

Notes

High Voltage

Laser Module & Stepper drivers need 12 V. Using a PSU that is 12V/20A (similare to the one pictured, but had to go for higher voltage to suit the DRV8825’s).

PSU Getting Ready

Enclosure (Air Exhausting)

Extraction and Filtering needed for any particles (smoke), or off-gases from lasering.

Extractor Getting Ready

(Box contains Activated Carbon from CO2 laser filter. Can evacuate air using this inline fan OR 4” duct/fan of C02 machine.)

Enclosure (Eye Damage)

  • Laser Module: 5W (±0.5W), 450 nm (± 10nm)

Laser Module (LT-40W-AA) (v0.3)

Laser Module 3D file

Links and references:

Electronics

  • For presentation, v0.3’s board is not working. It is likely a short, or bad joint somewhere that I haven’t traced yet. I will continue with the Proto-Shield until I get a chance to sort it.
  • v0.4 was to use a daughter board to break away remaining DRV8825 drivers, and not increase the complexity of either board too much. We will use a second shield, which is in the interest of a), saving resources (Arduino Mega shields are big, and it has taken 1x FR1 board to cut each test) and b), because the design of the v0.3 shield allows it. (Not intentional at the time, have to make sure I have enough headers etc…)
  • Note for self: Pay attention to track thickness… looking at Adrian and Neil’s examples, in particular.

So continuing from our Wokwi examples in v0.2/0.3…

Wokwi Examples

Pin Function
2 SD Card Detect (optional) SD Reader CD
20 SDA OLED SDA
21 SCL OLED SCL
24 Button 1 Button 1
23 Button 2 Button 2
22 Button 3 Button 3
25 ENDSTOP ENDSTOP
31 M1_STEP Ribbon White
33 M1_DIR Ribbon Grey
35 M2_STEP Ribbon Purple
37 M2_DIR Ribbon Blue
39 M3_STEP Ribbon Green
41 M3_DIR Ribbon Yellow
43 ENABLE Ribbon
45 Laser PWM
46 MOSFET Fan
53 SD_CS SD Reader
50 SPI MISO SD Reader DO
51 SPI MOSI SD Reader DI
52 SPI SCK SD Reader SCK
5v Logic Supply SD Reader, Ribbon Red
3v3 OLED OLED VCC
GND Ground general, ribbon black, ribbon brown

Soldered the ribbon cable as follows:

Colour Connection
Black GND
White M1 STEP
Grey M1 DIR
Purple M2 STEP
Blue M2 DIR
Green M3 STEP
Yellow M3 DIR
Orange ENABLE
Red 5V ???
Brown GND

Mechanical Redesigns

Mechanical Temp...