PCB Space Fighter - 3d PCB With DOTSTAR Illumination

Hi yall...

I was kicking around trying to think of a cool project for this Instructables PCB Challenge. I have a lot of them in the works. But nothing that could be finished in time.

I was talking with some of my friends who have kids (I am a Dink, duel income no kids).

I starting think about projects that would be good for kids. Something I could do when I have kids.

My wife and I where trying to adopt children. (Very long background story with lots of twists and turns) We are now trying to be foster parents. That journey has been long and difficult. But I digress

This is Long and short of it.

I want a good project that "kids from hard places" can look back and say "I did that". I wanted something that would catch there eye. But I also want something that would teach them something. Something that was all there's and a part of me. Basically a cool thing we could share. A project that we can do together.

Patience

FUSION 360

KiCad or Eagle

Hot Air pencell (hot air gun for soldering)

Low temp solder past

Gloves

Safety glasses

Tweezers

Microscope

12in AWG 16 Solid copper wire

20 Adafruit Dotstar LED's (AKA: APA102–2020)

5" of heat shrink

4 PCB wings

1 PCB Connector

1 PCB Body

3d Printed Stand

First I want to thank "Nakozen" (Peeto Skeeto) on Thingiverse.com. He makes a bunch of these 3D printable kit cards. You print them out and snap them together. They are cool. But he did one in particular that was VERY cool and caught my eye. His X-Wing Kit Card. (HERE)

The kits is basically is several flat parts that slid together. They are sort of a "snap-tight" 3d printable model.

The thickness of those parts happens to be 2mm. I can get boards in that thickness. I so could turn this into a PCB sculpture. Even better; I could add some leds...say some neo pixels. The pcb could then have power, ground, and signals for neo pixels running through the sculpture. I could even solder it all together. No glue.

With neo pixels, (we are actually going to use DotStar Micro LEDs (APA102–2020) ) and an MPU we could get some really advanced programming going on. Or with a lib the programming could be easy.

So good kid learning and I get to be a cool dad. Or maybe an nerdy dad who tries to hard. :)

The rest of this Instructable is how I made my boards. You can see the 3d render of the boards in the very first picture.

I am going to use KiCad as my PCB program. I know it the best, it's free; so, anyone can do what I'm going to do.

Nakozen's model is basically 3 parts. A connector, the body and, 4 wings. The model is a 2D cutout. That is good from me. I can use the outline of the part as my board shape. KiCad can import a DXF for the board out line. So I need to convert the STL outline into a DXF. That is fairly easy to do in Fusion 360.

Click on the video to see the basic steps.

I needed to make changes to the wings. The wing shape is to detailed for a board out-line. The lasers that come off the wings are also way to thin. I need to take out some detail and make the lasers larger. I also adjusted the slots for 1.6mm (62 mills) PCB thickness.

You will see those changes in the board later on.

Deep purple fans will get the title. if not go look it up...

I selected the DotStar Micro LEDs (APA102–2020) from Ada fruit (HERE) for the illumination.

I have a few reasons for this.

• The first is there are clocked serial. They are way faster than Neo-pixels and can do persistence of vision animations.

• The second is its clocked serial. If I have to clock the LED's very slow then the project is still viable.

• Lastly they don't have many connections and one LED drives the next. This is true for the clock and the serial line. That makes this much easier to do.

• They are easy to get.

The main reason I would need to slow down the clock would be due to the high speed performance of the boards. Or lack their of. It could be fine but then again; maybe not. I have never ran 1Meg Hz signals through a 3D PCB sculpture like this before.

The schematic for the body of the project is displayed in the picture. My plan was to put 4 LED's on each board. Two on each side of each board. That way led's can be viewed from any angle.

The body of the sculpture will need to have solder pads on the top and bottom for all the other boards. That is what holds this thing together. Everything needs to line up and be electrically correct.

I really don't want to design 4 different wings. I don't even want to design 2 different wings. So..... Drum role.

The wings will need to be electrically identical on both sides of the wing board. Or at least the electrical connection points to the body will need to be mirrors.

The Body board has 2 styles of SMT PCB connectors. Top side and bottom side. They are numbered from front to back. Same on the wing. So, no mater what side of the sculpture the wing is on; the electrical connections go from front to back. Now I can rout the board any way I want.

When we are all done the LEDs will all be connect in one serial line. 5 boards 4 LEDs, all 20 LEDs in one row. Just like on each board, but longer.

I really don't know you all that well; so it's just a cheeky title.

The connector board. There is really no schematic. It's only propose is to provide some mechanical stability to the sculpture. 5v and Ground are on it But that's it. The pads on the board are there so it can be soldered to the body of the fighter.

The only connection that is supper important is the ground slot for the AWG16 wire. You will see that in the construction steps.

Sorry no snarky title....I had no ides

I have another video to import the dxf in as a board outline in KiCad. It also shows how to line of the solder pads so the signals can pass from board to board.

The sound got a bit on the low side. I'm still learning on how to make a video like this. But you get the picture of what to do.

The placement of the LED's is for effect only. No real electrical considerations where taken into account when placing them. Which is why I'm a bit concerned about the data rate to the LEDs. The led string goes down one side of the board and back on the other. All 3 PCB's are that way.

It time to solder the LED's on the board. The APA102–2020 are only 2mm across. Not the smallest part I have ever soldered. But all the pins are underneath the part. It is not easy. It also looks like I botched the solder mask. Solder dams should have been in place. But they are not.

I add a small amour of solder paste to the pads put the part on with a micro scope. I used my hot air pencell to heat the part and the board. The hot air will melt the solder but does not move the part. (if set right) . When the board, part, and solder are at the right temp. I tap the board. This gets the surface tension of the solder to pull the part to the center of the pad.

I had to pull one or 2 LED's off the board. I cooked one of them during the soldering process.

I went slow and was carful and it took me an hour per board. About 15min per LED.

Once all the LED's and bypass caps are placed you can start assembling them into the fighter.

I'm using a AWG 16 solid copper wire (stripped out of some old house wiring) as my ground line. It's also the rod that's going to hold the fighter above the stand.

As it so happens AWG 16 wire is .062 or 1.6mm thick. Same as our boards.

So I tinned the tip and then soldered into the body. With just a little solder. Then I mashed on the connector PCB. I made sure the two boards where 90 degrees from each other. I then soldered the 5v Pads on the connector PCB to the body. There are four 5v pads.

Now come the trick part. Add a little flux to the ground pads and AWG 16 wire. Then apply heat with your iron and then add some solder. The goal is to solder all 4 ground pads and the AWG16 wire at once. This provide the electrical ground connection and a machinal post for display.

Notice none of the boards have their electrical components on them. These pictures where taken when I was building the mechanical test unit. I built one fighter to check that it could be assembled, take pictures, and to do a continuity test on. It passed with FLYING COLORS. (pun intended)

The real test will be to put LED's on the board and light them up.

Ok we will need to get the CLK, Data, Power and GND on the fighter. The AWG 16 wire will be the ground. The magnet wire will be used for the other signals. The signals are labeled on the fighter body board.

Once they are soldered on label the ends. You will need that later. Run all the wires down the length of the AWG 16 wire. Bundle them all together and put a long section of heat shrink over them.

The stand rod will be black (or whatever color you used, I used clear) and look like one part. But it will actually be everything to run the electronics on the fighter.

I am working on a stand that will house the controller and power. That will be out soon. The stand will hold the wire upright and have the control electronics. So, the whole thing is going to look like a fighter, on a stick, on a stand (holding a tic tac - thanks Jeff).

The wings get attached one at a time. I use some painters tap to keep each wing in place while I soldered them.

The pictures show the top of the sculpture. When you flip the body over to solder the bottom wings; it looks very much the same.

This was actually a little bit difficult. The pads a close together and its easy to make a short. I had to use some solder wic a few time to get the excess off.

As you can see there is lots of white space. That was on purpose. Even if my kids don't like electronics they can decorate the fighter. My dad had RC cars. Never did get into that but I had fun painting them.

The one in the picture I numbered the wings for testing. Permanent marker works well. But what is even more fun is water slid decal paper. Same idea as the decals you put on snap-tite models as a kid. But you can run them through an inkjet.

The possibility's are endless.

My plan at this point is to use a PsOC 5LP as the controller for the LED's. They are cool little parts. They have programmable logic blocks and pin functions can be moved around.

CY8CKIT-059 is $15 at Digi-key. Not the lowest cost controller. But it beats Arduino because it has A DEBUGGER!!!!!! Oh and native USB. PsOC creator is a better IDE and this thing is easy to use.

I also have one.

I will add more about this in the make it glow contest.

So this is the last page for now. I have a lot to do to get this to light up. The contest is about to close so I will finish this up in the make it glow contest.

There are lots of opportunity's for kids to participate at different levels. From the really hard to painting the project.

So if you want to make change or other wise use my work it is licensed under Creative Commons

Space-fighter by Adrian West is licensed under Attribution-NonCommercial-ShareAlike 4.0 International

If you want the source files or the gerber data for building your own go (HERE)