Build Frame

A frame of some sort holds your “light paintbrush” together, providing a base onto which components can be firmly attached.

Thus begins the Choose Your Own Adventure part of the project. There is no One Right Way to do this. Your access to and experience with different materials and tools might be entirely different than what’s shown here, so consider these merely guidelines, not a blueprint.

Think About Materials

There exist some really nifty metals out there — including aluminum extrusion and U-channel — but these are relatively costly and require special tools and skills to cut and join. If you’ve got the chops and the budget, go wild.
For most folks, wood is probably a better choice. Inexpensive, easy to acquire, easy to work with.

This 3/4" pine molding is the perfect width for the NeoPixel strip. It typically comes in 8 foot lengths, which can be cut as needed.

Unfortunately, the dowels in the “hobby wood” section of most hardware stores are typically 36 inches long…just a bit too short to support a full meter of NeoPixel strip. So you’ll probably need to buy a full 8' length of molding. Many stores will provide one or two cuts for free.
If you must buy your wood from a big home improvement store, sight down the length of the boards and try to find one that’s relatively straight. A local independent lumberyard or hardware store will usually have better quality stock in this regard.

PVC pipe might seem an alluring option, but it’s not recommended. It lacks rigidity, and the round cross-section is difficult to attach the NeoPixel strip to.

Think About Shape

How big will your paintbrush be? In what ways do you envision moving it around?
The simplest support frame is just a straight bar a bit longer than the strip itself. This provides a grip at one or both ends…it could be lifted like a barbell, or brandished like a light saber.

A “T” configuration puts the grip at the center, providing different options (such as spinning).

Or you could mix and match. A “T” with a longer bar for multiple grip options.

The bar should be a minimum of 42 inches long…that’s just a little longer than the 1 meter strip with the end caps.
If you’ve opted for wood and a “T” configuration, the two pieces can be held together with a pair of 3" zinc tee plates and ten 3/8" wood screws.

Mark and drill some small pilot holes, and screw the frame together…
Super easy!
Or, to make a frame that can be dismantled, drill all the way through the wood and substitute bolts and wing nuts.

Think About Stray Light

There are a few LEDs on the Arduino board and shield that could produce undesirable light streaks in your paintings, so consider some kind of enclosure.

We used an Altoids-sized mint tin for ours…it’s almost exactly the same size as the Arduino and shield.

Some sections of the enclosure need to be cut away. Metal can be difficult in this regard, and there’s the risk of cuts from sharp edges.

If you prefer plastic, there's a nice weatherproof box in the shop that is easier to work with - you can drill and cut it with basic hand-tools.

As an alternative, you might track down a plastic box that’s big enough for the Arduino and shield. Even a small paper box (like playing cards come in) may suffice. Look around you!
If you do use a metal tin, devise a scheme to insulate the electronics inside. This needs to be done on the inside top and bottom.

Here the footprint of the tin is traced onto index cards and cut out to produce a liner. Later this will be glued or taped in place.

Vinyl contact paper is another option, if you have some in your craft stash.
Cutouts must be made for the USB port and SD card socket. Using the Arduino and shield for size and position reference, outline the planned cuts with a permanent marker.

Notice with this tin that the SD slot needs cutouts both in the base and the hinged lid.
Add a single cutout for wires at the opposite end of the enclosure as well.

Also, mark two spots on the bottom where screw holes can be drilled. These will hold the enclosure to the frame.
How you cut the tin will depend on your tools on hand. Dremel? Metal snips? Files?

Watch out for sharp edges, and wear eye protection when using tools!

After cutting, metal edges can be smoothed with sandpaper or an emery board (nail file).

Wash out the case thoroughly after doing this, and allow it time to dry. Any lingering metal shavings or dust will wreak havoc with the electronics!
The enclosure is mounted near one end of the bar in order to minimize the wire lengths between the Arduino and NeoPixel strip. Attach it to the face of the wood that’s opposite where the LED strip will go. Later, we’ll position the batteries to provide a counterweight.

The tin shown here was painted matte black to reduce reflected light from the environment. Not a crucial step, but go ahead if you already have some paint on hand.
The insulating layers that were cut earlier (if needed) can be installed in the case now, using glue or double-stick tape.
This guide was first published on Dec 10, 2013. It was last updated on Dec 10, 2013. This page (Build Frame) was last updated on Nov 20, 2019.