Imperial Journey

My vision for the Dragon Paw holding the Orb was a dark green mottled skin with dark yellow claws. The 3D printed paw was black. Well, this is what they make airbrushes for.

Order a set of acrylic model paints in different colors. The one for painting military vehicles has an assortments of greens and browns that look like they will work.

Spraying paint next to the Imperial makes me nervous. Fortunately this is a solved problem – a paint booth will draw air away from the airbrush and filter out all of the paint overspray. It also provides task lighting and includes a turntable for painting.

Start with a coat of primer. This let’s me practice with everything and provides a base for the rest of the work.

I’m looking for a muddy green for the skin, so start with olive drab and mix in some dark brown. Keep adding brown until it is muddy enough. No need to worry about color changes – I’m looking for a lot of variation. With green on everything clean out the airbrush and load it up with a little bit of dark brown. Spray patches of brown overcoat on various parts of the paw – not covering up the green, but giving it slightly darker areas.

Lean back and study the results. Hey, this isn’t too bad! It is ugly, uneven, and blotchy. Perfect – just like a dragon skin!

For the yellow claws I need finer control that I can get from the airbrush, so dig out the model paint brushes and brush on a coat of yellow. Discover that acrylic model paints have poor coverage and end up applying six coats.

The end result is very close to what I had in mind originally. And there was much rejoicing!

With the Orb working it was time to start working on the programming. Which would involve turning it on and off repeatedly. Well, we needed a power switch to actually use the Wizard Staff. Might as well go ahead and design and build a switch.

Do some research and select an on/off switch and order a bag of them. I’d been thinking about this for a while and decided that the “bracelet” below the dragon paw was the best place to mount it.

You know what is coming: Fire up the CAD system and design the switch into the bracelet. Print out the bracelet and test fit the switch. It works, so go ahead and wire it up.

This let me start on programming. The electrical engineer let me know that the batteries were on order, but it would be a few days before they were in. No problem; it makes more sense to do all of the development work with external power.

Except that I can’t completely assemble the Orb with the power wires in the way. And it would be really convenient to be able to choose between internal and external power.

Hmm… If I used a DPDT power switch I could choose between battery and external power. And it would be convenient to have a real power inlet on the staff. One that the external power supply could just plug into. A bit of research and order new switches and connectors.

Back into CAD and redesign the bracelet for the new switch and power inlet. Print it out and test fit things – everything fits! It is almost like I’m getting better at this design thing!

Assemble the Orb, dragon paw, and bracelet. Wire everything up. Test it: works on external power and should work on batteries when they show up.

NOW I can get serious about programming. Dig into WLED and (re)learn about effects, presets, and playlists.

Recall that we want to have interactive control of the Wizard Staff. The WLED controller has two I/O lines that can be used with pushbuttons. I had a bag of pushbuttons ready to go. Study the staff for a few minutes. Looks like the adapter between the bracelet and the shaft of the staff is the most convenient place to reach the buttons.

Back to CAD, design in the pushbuttons, and print out a new adapter. Hey, the pushbuttons fit! Wire everything up, assemble the pieces, and get back to working on the lighting effects.

After an hour or so of playing with various settings and effects there was nothing left but admitting defeat. The LED strips on the bottom of the railing were great accent lights and terrible Christmas lights.

As I sat sulking in my chair, glaring at the lights, I recalled that I had an “extra” roll of pixels from the Mega Tree build. These were basically Christmas lights. Find where I hid the roll, plug it in to the end of the under-rail lights, and loosely wrap it around the railing to see how it looks. Fire it up and stand back.

And it looks great! This is what Christmas lights are supposed to look like! Hmm, three strings would cover the entire railing. Head to the computer and order two more strings.

With a full set of light strands in hand it was time to wrap them around the top rail. She Who Must Be Obeyed suggested “you know, it would look nice if they were draped from the (horizontal) wires”. Why yes, yes it would! And this makes it easy to adjust the length – just fiddle with it until everything was bowed the same amount.

Grab a handful of zip ties, fiddle with the spacing, and zip tie the lights in place. “Patiently” wait for nightfall and fire up the lights. Now This is Christmas!

Login to the WLED controller and start trying the 100+ effects that WLED provides. Find a half dozen that I like and save them into a playlist. Sit back and admire our now festive deck.

Not quite a “I meant to do that!” situation, but worked out in the end.

Tis the season again. Pick a (somewhat) “warm” day and get all of the Christmas decorations up. To my pleased surprise I found all of the pieces of the Mega Tree, put them together, and everything worked! How did that happen???

Night time rolled around and everything looked great. Then She Who Must Be Obeyed asked the question: “Can we add some Christmas lights to the deck railing?”

Why, yes! Yes we can!

I’ve been thinking about adding lights to the deck railing ever since we installed it. This provided the impetus to actually do something.

My vision was to add accent lighting to the bottom of the railing. You want to control the brightness, so dimming is a requirement. There isn’t much difference between white LEDs and full color LEDs, so might as well go with color changing LEDs.

Or, even better, based on my experience with the Mega Tree, go straight to computer controlled pixels. This let’s you do full Christmas effects! Clearly the only way to go.

This time use the full size LED strips which are much easier to work with than the ultra narrow strips from the Wizard Staff. The full size strips are available in outdoor versions which have a heavy silicone sheathe that protects them from the weather and from damage. And they have an adhesive backing, so just peel ‘n stick on the bottom of the railing.

Right. You know better than that…

I don’t trust adhesive to stand up over the long term for applications like this. They also make a U-shaped aluminum channel for mounting LED strips. These channels have a snap in plastic cover that locks into place over the LEDs making sure they don’t go anywhere. Even if the adhesive fails completely everything is still secure.

And the channels are white, so they will blend invisibly into the white railing.

These channels are commonly held in place with double sided tape. Or…. You can run screws through the bottom of the channel. But the railings are (heavy) steel – you can’t run screws into that.

But you can drill and tap holes for machine screws. And I have drill bits. And taps. And a box of 8-32 stainless steel machine screws.

Order the LED strips, aluminum channels, and the electrical cable to wire everything up.

Drill and tap the holes in the bottom of the railing. Since I am experienced and careful I was able to accomplish this with only one broken tap. Screw the channel into place. Hey, it does disappear!

Now to install the LED strips. Thes strips come in 16.5 foot (5 meter) lengths. The long side of the deck is 22 feet. And I need a right angle connection.

Unlike my experiences with the ultra narrow LED strips, these full size strips are easy to work with. Cut to length, solder wires to the pads, and cover the connections with hot glue to protect and insulate. Check the full length on the bench and everything works.

Take the 30 foot long LED strip to the deck, peel off the backing, and stick it inside the channel. Come back and pop in the plastic covers and Viola! Done!

Hook up the WLED controller and test it. Still working! And there was much rejoicing!

Wait for nightfall, fire it up, choose some different WLED patterns, and admire my handiwork.

It was boring. It worked perfectly, but had no impact. You couldn’t see the LEDs – they were inside the channel, behind a diffuser, and below waist level. The light was shining down on the deck providing the accent light I had originally envisioned. It was nice, but it just wasn’t Christmas.

Crud.

To be continued…

WLED can treat a string of LEDs like a TV and display complex images and animations. Basically it treats a string of LEDs like a two dimensional matrix.

It does this by arranging the LED string in a serpentine pattern. The LED string goes up, down, up, down until it fills the 2D array.

The intelligent LED strings I’m using can be cut apart and re-connected between any two pixels. The backing for the string has three copper pads that can be connected by soldering wires to them.

With standard 1/2″ wide LED strings this is (somewhat) easy to do. With the ultra thin 2.7mm high density strings it is a nightmare.

To make the display look right you have to have the same number of pixels in each row. The original plan as to cut eight strips the same length and solder them together.

I tried. Several times. Managing to destroy several lengths of LEDs. The worst part was actually getting the connections to work a couple of times – until you moved the strips and the solder joints failed. I didn’t have the skills, equipment, or dexterity to pull this off. At lest not with any trace of reliability.

The electrical engineer proposed just wrapping the LED string up and down without cutting or soldering anything. This “wastes” some pixels at the top and bottom where you reverse direction of the LED string, but it avoids the need to cut and solder.

The first time I tried this I bent the LED string too much and damaged it. I tried cutting out and repairing the damaged sections. It almost worked. I managed to get the whole string to light up a couple of times. But as soon as I touched anything the fragile solder joints failed. After about three hours I gave up and ordered another roll of LEDs.

With the new roll of LEDs in hand I very carefully ran the string up and down the ribs of the inner framework. At each end I used the largest bends I could and left as much slack as possible in the string.

Completely paranoid now I checked the LED string for proper operation as I installed each of the eight legs. This time the whole string worked.

Slip the controller into its pocket and connect it to the LED string. Plug the controller into an external power supply and turn it own. The LEDs sprang to life!

So far, so good. Fire up the laptop, connect to the WLED controller, and start trying different patterns. It works and looks great. And there was much rejoicing!

With the CAD work done and parts in hand the next step was to actually assemble the Orb. Of course the electrical engineer had some last minute changes. Batteries kept falling out of the battery box, so he selected a different one.

Good news: the new boxes were close enough in size that the fit on the mounting plate. Bad new: the new boxes had different mounting holes.

No problem! Grab the 3D solid models for the new battery boxes and add them to the CAD assembly. Delete the mounting holes for the old boxes, project the mounting holes for the new boxes, and hit print.

Mount the battery boxes and screw them into place. Slide the voltage regulator into its slot. Slip the controller into its pocket. Everything fits!

Now we just need to wire everything together.

But before that we need to install the LED strips.

With the controller in place the next question was how to power it. The electrical engineer determined that we would need four 16650 Lithium Ion cells and a voltage regulator to make this work. He identified the parts he wanted to use and sent me the part numbers.

The datasheet for the voltage regulator had a mechanical drawing with dimensions. OK, that gives me the information I need.

The batteries would go in two battery holders, each holding two cells. Tracking down the part number on the Internet I discovered one of the greatest advances of civilization in the last 20 years: dimensionally accurate downloadable 3D solid models of the parts! I knew that these existed, but this was the first time actually using them in anger.

Let me see… The battery holders needed to be mounted on a flat surface about “this” big. Play with geometry for a few minutes and I had a rectangle the needed size positioned between the Orb ribs. Extrude it about 0.080″ thick and I had a mounting plate for the battery holders fused into two of the ribs.

Position two of the battery holders on the mounting plate. Project the mounting holes from the battery holder model to the Orb inner structure model. It all fits and looks good.

Rotate the Orb around and add a mount for the voltage regulator to the back of the battery mounting plate. The voltage regulator is a tiny 1″ x 1″ circuit board with components sticking up. Design a slot for it to slide into with plenty of room on both sides for air flow – voltage regulators can produce a fair amount of heat.

Assuming the actual production parts fit the Orb should be ready to go!