nanoDLP

So the built in NanoDLP G-Code guide is ok, but I had to spend a TON of time figuring out how the interface actually works. My printer is a VERY simple clone of the Chimera printer on Instructables. The set up is GRBL 0.9j with the SolidRay patches running on a chinese Arduino Nano clone and an EasyStepper v4.4 driver driving the carriage from a PlayStation 3 Blu-Ray drive. My build platform is perfboard, my vat is a glass cup.

To save others the trouble, this is a quick run through of what worked for me. I've tried to annotate the G-Code as much as possible, so each function is clear. I'm happy to clarify if anyone needs it.

**G-Code - Bootup :**

None

**G-Code - Start Of Print:**

$X ; Unlock GRBL in case we're in an alarm state
G90 ; Put GRBL in absolute mode
$H ; Home GRBL so we can start from a known place
G4 P0.1 ; SolidRay movement sync
[[WaitForDoneMessage]] ; Wait done message
G92 X0 Y0 Z0 ; Set our new homed position as the origin
[[PositionSet 0]] ; Set the current position as 0 in NanoDLP

**G-Code - Before Each Layer:**

G01 Z[[LayerPosition]] F100 ; Move to the correct layer height
G4 P0.1 ; SolidRay movement sync
[[WaitForDoneMessage]] ; Wait done message
[[PositionSet [[LayerPosition]]]] ; Save the current position in NanoDLP

**G-Code - After Each Layer:**

[[Delay 1]] ; Wait 1 second for the resin to “settle”
G01 Z{[[LayerPosition]] + [[ZLiftDistance]]} F100 ; Dip the platform by the lift distance
G4 P0.1 ; SolidRay movement sync
[[WaitForDoneMessage]] ; Wait done message
[[Delay 3]] ; Wait 3 seconds for the resin to settle and air bubbles to pass
[[PositionChange [[ZLiftDistance]]]] ; Again update position

**G-Code - End Of Print:**

$X ; Unlock GRBL just in case
G01 Z0 F100 ; Bring the platform above the resin level

**G-Code - Resume Print:**

$X ; Unlock GRBL in case we're in an alarm state
G90 ; Put positioning in absolute mode
G92 Z[[CurrentPosition]] Y0 X0 ; System crashed so we need to recover current position from NanoDLP and set it in GRBL
G1 Z[[LayerPosition]] F100; Move to layer position
G4 P0.1 ; SolidRay movement sync
[[WaitForDoneMessage]] ; Wait done message

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Because my set up is so simple, the build platform is attached to the drive sled with a rare earth magnet, it's leveled by bending its attachment post. The resin is poured to be just barely BELOW the homed position of the build platform, and all of my models include a "raft" like structure at their base so that even if the printer "misses" a few layers it'll still start with a non-critical part. To start a print, I manually push the build platform to near the bottom of the resin tank. This is because the G-Code is going to home the platform anyway, and it ensures that there's a very thin layer of resin on the platform.  Because the platform starts technically above the resin level the final end of print G-Code returns the platform to 0 and the printed piece rises from the resin, ready for post curing.

I've had a number of excellent prints with this current set up, my only issues are 100% software based. I still need to tweak the cure time, as well as the amount of time to let the resin settle. I'll post pictures of some prints, as well as the castings they'll be turned into soon.