Step 1: Hello World: Building a Simple Circuit with the Othermill
The Othermill is a nifty little desktop mill that can fabricate amazing things out a variety of goods. Printed circuit boards for electronics are something it handles nicely.
Here's a tutorial for a basic board to play with. It's the first public project we released for the Othermill: "Hello World!"
Step 2: Assemble Your Materials and Equipment
- An Othermill
- A soldering iron and solder
- A hot glue gun
- Diagonal cutters
- Calipers to measure your board
- “Third set of hands” (optional)
- Safety glasses
- 1 - single-sided FR1 printed circuit board blank
- 2 - 47 Ohm resistors
- 2 - LEDs (we used 3mm red and green ones)
- 1 - Coin-cell battery (we used a trusty 3V CR 2032)
- 1 - Coin cell battery holder (we made sure ours fit our trusty 3V CR 2032)
- Double sided sticky tape
- A basic understanding of how a simple electrical circuit works (Here's a nice explanation)
- Basic soldering (Here's a splendid tutorial)
- A basic understanding of what milling is (Here's a quick but effective video)
- The willingness to pick these skills up while you make this project (it might take a little longer, but if you've never done it before, you'll feel like you just invented fire).
Step 3: Set Up Your Othermill: Getting Started
Download the EagleCAD .brd file called "Hello World" attached to this step.
Have a look at our Othermill Getting Started Guide, if you haven't yet used your Othermill. It'll show you how to get the machine set up for milling, and how to download and install Otherplan, the Othermill motion control software.
Turn on your Othermill and home the machine when you are prompted.
Step 4: Set Up Your Material
Launch Otherplan, and click on the "Setup Material..." button in the "Setup" panel.
Use the calipers to measure the exact height, width, and depth of your FR-1 blank.
Select "Custom Width," and add in the X, Y and Z dimensions of your PCB. Click "Continue..." and "Done."
Step 5: Set Up Your Tool
In the "Tool" panel, select "Change..."
Select 1/32" Flat Endmill, and run through the steps to insert, setup and locate your tool.
The Othermill has presets for a bunch of different tools. This means that feeds and speeds and other tooling settings take care of themselves, with no fiddling with charts and manuals (trust us, if you are a machinist this is a big deal).
What this means for an Othermill user is that once you select the tool in Otherplan, the machine will know what to do with it.
Step 6: Set Up Your File
Click on "Import Files..." from the "Plans" panel.
Select "HelloWorld.brd" from wherever you've saved it.
The board design should appear in Otherplan on top of the rendering of the material.
In the "HelloWorld.brd" panel, select the 1/32in Flat Endmill as both the trace and the outline tool.
Set your trace clearance to 0.
You are now (nearly) ready to cut your board!
Step 7: Insert The PCB Blank
In the Move By panel, select Unload Material. (You can also choose Machine > Load/Unload Material from the menu bar.) This will bring the machine bed forward.
Put a few strips of double-sided sticky tape on the back of your board.
Square the board up on the lower left hand corner of the machine bed and press it down firmly.
In the Move By panel, select Load Material. This will bring the machine bed back into the correct position for...
Step 8: Cutting your Traces!
In the "Plans" panel, click on "Cut Traces..."
The Othermill will give you one more chance to make sure everything looks right. Verify that the board is secure to the bed, and double check all your settings. Put on your safety glasses, and snap the Othermill's safety windows into place.
Click on "Cut Traces" again.
The Othermill will descend dramatically to the surface of the material, and with a pleasant buzz start cutting your traces.
This mesmerizing process will take about 20 minutes. It's a good idea to collect anything you might need and get comfy before you start, because you should never leave your Othermill unattended while it is running.
Step 9: Cut Your Through Holes!
After the Othermill has cut the traces, it will return to the home position. Click on "Cut Outline..." in the Plans panel.
The Othermill will begin drilling the through holes for your board.
If you are using a PCB blank that is larger than your finished board, you can let the Othermill continue cutting out the outline of the board after the holes are drilled.
If you are using an FR1 blank that is cut to size for your board, you can stop cutting after the holes are drilled. To do that, first click the Pause button at the bottom of the Otherplan window, then click the Stop button. This will stop your machine and return it to home without it cutting an unnecessary outline.
Step 10: Inspect Your Finished Board
Click Move By > Unload Material to bring the machine bed forward.
Gently pry the cut board off the machine bed with a flat blunt tool of some kind. A cheese knife works really well for us, but be careful not to damage your board.
Have a look at the finished board and make sure it looks correct.
It it does, it's time to light it up!
Step 11: Assemble The Board: LEDs
Find the two sets of holes on the bottom corners of your Hello World board.
One at a time, insert the LEDs into the holes, from the back of the board.
The long wire on each LED should be inserted in the hole closest to the outer edge of the board. Push them in all the way, but don't force them!
On the front of the board, bend the LED wires so that they line up with the traces you are soldering them to. (A “trace” is a line on a PCB that transfers signals and power.)
Solder the wires in place, then clip them with the diagonal cutters. Clipping wires prevents short circuits, and also makes the board look nice.
Step 12: Assemble Your Board: Resistors
Insert the resistors into the holes at the top of the board, from the back – just like the LEDs. Resistors have no polarity, so you can drop them in any which way.
Bend the resistor wires to match the traces before you solder them, the same way you bent the LED wires.
Solder the resistors into place, and clip the wires close. Save a longer piece of resistor wire – you’ll use it later to connect your ground.
Step 13: Assemble Your Board: Ground
On the back of the board, take the wire you saved from the resistor, and place one end in the bottom-most hole, just below the W in World.
Place the other end through the hole in the middle of the milled circle. Bend the ends of the wire a little to keep them in place.
Turn the board back over, and solder the ends of the wires into place.
This wire will connect the front of the board to the negative pole (the ground) of the battery.
Step 14: Assemble Your Board: Power
Turn the board over so you are once again looking at the back of the board.
Hold the battery holder in front of you so that the + sign is on the bottom, and facing you (see photo).
On the right side of the holder, locate the small terminal tab and poke it through the top hole (the only empty hole on the board at this point).
Turn the board over, and solder the terminal into place.
Step 15: Assemble Your Board: Complete the Battery Holder
Clip off the other terminal tab on the other end of the battery holder, and hot glue that side to the back of the PCB as shown.
This is important, because if you solder both sides of the battery terminal into holes in the board, you'll create a short circuit and your board will not work.
Step 16: Light Up Your Board!
Once the hot glue is firmly in place, slide your coin cell battery into the battery holder with the flat side (positive) up, and the rounded side (negative) down.
Your LEDs should light up, and your board should salute you with a cheery message.
Now that you have the basics, you can make all kinds of things on your Othermill.
Contact us at [email protected] to tell us about your projects (we'd love to hear about them!), ask us questions, and discuss issues.