Monday, October 6, 2014

My first Uncia print!

Finally stopped thinking about Uncia upgrades long enough to actually print something on the bot! Printed in MakerJuice SubG.

The color change of the resin is pretty interesting... but past that it's not the best model in the world. Granted, it's way better than nothing, but some calibration obviously needs to be done. What's pretty cool is that the only variables are resin exposure time, layer height, and the dwell period on each layer (to let the resin settle). Hopefully I can dial this in nice and quick!

Kudos to Uncia for making such a solid machine... and bigger kudos to Sedgewick for the original design!

The model I was trying to print was the 3D Hubs Marvin - Key Chain. Attribution!

Thursday, October 2, 2014

Uncia Electronics -- In Depth

I haven't seen this in a lot of other places, so it's going here!

The Uncia's electronics are (like the rest of the machine) and clone of Sedgewick's electronics. They comprise of a Teensy 2.0 and a single Pololu A4988 stepper driver. Also included is the smallest, most adorable 12V 1A power supply.

The two boards are mounted on a very simple circuit board.

Yes, that's all there is to it. Click the images to see a close up

It's a bit difficult to see all the connections. I've recreated the board in Fritzing.
This is a simple version -- It just shows what Teensy pins go where. Note that the LED shown is the signal LED that is on the Teensy itself.
Now for the real deal:

This is (I believe, unless I screwed up) the full breadboard for the Uncia.
Please note that Pin 10 is tied to a +5v. I'm not sure why this is the case (Since Pin 10 isn't even used in the firmware), and it doesn't make sense from a circuit design standpoint. I'm assuming it's a mistake. If you're ever pressed for pins enough to need number 10, it's easy enough to slash the thin trace that connects the pads.

Anyways, it's clear that the Teensy isn't being used to its full potential. This is actually pretty nice, as it allows for upgrades to the printer without having to swap the electronics!

With these upgrades in mind, I scribbled out the layout of the breakout pads that litter the board.

The layout of the three pads that line the board.
I don't like how the 5V pin is in between the GND and Signal pins -- it means that you can't just use a simple 2 pin BLS connector. C'est la vie, I suppose.

When programming new firmware in the Arduino IDE for Teensy (Teensyduino), just keep the following image in mind:
The numbers closer to the board are the pins called by Arduino code.
Note that pins 7 and 8 are both reserved for Rx and Tx -- if you attach inputs to these that force a HIGH or a LOW, you won't be able to upload new firmware.

All of this information will be used in the improvement of the Uncia firmware (Or should I say the Sedgewick firmware...). Check it out!

Wednesday, October 1, 2014

I finally understand GitHub!

So a few weeks ago my new Uncia DLP 3D Printer came in the mail. This is really some cutting edge technology, and I'm excited to be able to play around with it!

The hardware of the bot is pretty simple and solid -- a steel frame, a linear rail, and a stepper motor.

The electronics are a bit eccentric, however -- a stepper driver controlled by a Teensy 2.0!

The firmware's totally wonky -- it uses "pseudo gcode", and essentially expects the computer running the Teensy to do all calculations.

The software is nearly there -- I'm using Steve Hernandez's Creation Workshop, and, with the inclusion of a custom Uncia driver to support the weird firmware, it works pretty well.

There were some things that I wanted to change in the software, though... The first and foremost being the ability to turn off the damn motor! The electronics aren't tuned perfectly for the motor, so it hums pretty loudly, even while idle. There was a button on the CWS to turn off the motors, but it didn't do a thing.

So I turned to GitHub, and logged into my old account. How coincidental that I made my account on October 1st, 2012, and pushed my first commit Octobor 1st, 2014! Git's become a lot more usable since 2012 (At least on Windows).

You can see my repository here, but it probably won't be that interesting unless you also have an Uncia.

Hopefully that repo will see some serious action as I start to tune in my bot!