(Another) 500mm x 300mm x 125mm build!

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    Mike Cunningham

    I will edit this in the future, and put specifics, but for now, picture.

    btw, that xbox logo was burnt at 38mm, power setting 0-22, 4000mm/min (3.8w laser)

    * 1/2″ MDF sitting on top of 1×3″ pine on 6.75″ centers

    Ramps 1.4-ish/arduino:
    * Removed the backpower diode on the RAMPS board, added a 7805 regulator to provide 5v servo power (ended up not using it)
    * Removed all 5 baby capacitors under the Pololu drivers, and soldered leads to 32v 440uF capacitors for the steppers. Now they don’t starve.
    * Custom case, slides over the whole assembly, with a 50mm fan holding it together
    * Removed the USB Poly fuse on the arduino mega 2560 R3, so the board is never powered by USB.
    * desoldered the power connector, re-soldered the hot going to where the polyfuse used to go; so voltage in bypasses the regulator.

    Power Supply
    * 30-year old AT 350w power supply with 36A of 12v on a single rail. (20a for steppers, with plenty of excess for laser/extruder/heater/fans)
    * lots of wire clipping inside to reduce the octopus coming from the back of it.
    * Controlled via Marlin, but set to turn on by default. I add an M81 at the end of long runs to power it down when complete.

    * 84 oz/in, with 9mm wide GT2 belts, 20t pulleys, and “custom” idler pulleys (this could be a post in its own)

    Printed parts:
    * 100% ABS, at recommended infill settings. Stepper mounts sag a bit, and I plan on redesigning them with considerable reinforcement.
    * I stuck with everything being ABS, to absorb the vibration of larger routers better.

    Micro-router head:
    * Dremel 200, with “custom” bearings ABEC-7 ZZ’s, shimmed in, and backfilled with fiberglass, for accuracy
    * Used for extremely fine detail and finishing (0.15mm milling bits and whatnot)
    * Custom mount, holds tight enough for 0.0025mm accuracy.

    Mid-router head:
    * Dewalt 660, basic off the shelf setup, with a Hall Effect sensor superglued inside of the head.
    * RSC-9400 speed controller, with a servo stuck on the knob (seriously) http://www.thingiverse.com/thing:1635710
    * Standalone Arduino Pro Mini dedicated to maintain specific RPMS (controlled via I2C from Marlin) .. Again, specifics could fill a whole post. The way Marlin beats up the timers, PWM from the 2560 is not reliable enough to control a servo.

    Heavy-router head:
    * TODO. Random brand 1800W variable speed router sitting in a box, still have to crack it open and design a mount. Have not found anything the Dewalt couldn’t tackle yet though.

    Laser Head:
    * 2.8w Diode (Nichia NDB7875 445nm 9mm Laser Diode In a Copper Module With Leads & Glass Lens, from DTR’s Laser Shop)
    * 3 Element Glass Lens
    * China special driver (A10?)
    * 32mm x 32mm x 62mm Aluminum Heatsink (Keeps the laser at room temperature.)
    * 2x line lasers for aiming
    * Intel PIII Heatsink Fan as the primary cooling fan
    * 30mm fan mounted below for smoke evacuation, with an endstop screwed to the bottom of it
    * High quality, top of the line random re-used piece of a bed liner cut out as a shield to reduce harmful reflections.
    * Custom made mount.. didn’t like any of the existing ones, and I wanted to use the PIII CPU Heatsink fan 🙂

    Print Head:
    * TODO. Will be a Direct-driven J-head. Have all of the components, just need time to design the mount.

    Z Tower:
    * Custom Gang Box with a 4-pin and 8-pin GX-16 connector. 4-pin has +12v, +5v, GND, D9- (fan), 8-pin has D44 (Laser Enable), D8-(Extruder Heater), A13(THERM0), D18(ZMIN), D11(Servo1),D6(E0 DIR),D5(E0 ENABLE),D4(E0 STEP)
    * 5/16″x12″ SS threaded rod, hardened, with a flat ground into the top to lock into the pineapple coupler.

    * There are not many parts of Marlin that I have not rewritten. Let’s just say its custom.
    * M3 Sxxxx, 0-255 sends PWM to D44, for laser level, 3000-35000 sends I2C command to router speed controller and turns on Dewalt 660 power relay
    * M5 turns off DW660 relay and D44 (Laser Enable)
    * M10 turns on Vacuum relay
    * M11 turns off Vacuum relay
    * Added st_synchronize to M3, M5, M10, M11, M106, M107, and a dozen other commands, so they are executed in the proper order… otherwise the laser will just pulse off for a split second while doing a G00, and cut lines while traveling.
    * Modified stepper_indirection.h to run X/E0 and Y/E1 in paralell, so each DRV8825 is powering an individual stepper; so I get a full 2A to each stepper faster, so they hit max current quicker, and do not slip.. tried wiring them in series, but with the current going through 2 steppers, 12V is not enough to push 84oz/in steppers to their limits.
    * Changed E0 to D6,D5,D4; DRV8825 for the extruder will be mounted on the extruder. (3 data wires, instead of 4 magnet-making power wires.. plus RAMPS only has 5 drivers; no room for a 6th)

    **more specifics to come


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