Plexitube Owl Clock

owlTickAnimationSmallFor Christmas I designed and built six steam-punk owl clocks that have a novel faux Nixie Tube display. Nixie tubes are wonderful with their glass tube bodies and brightly glowing numerals, but think how wonderful a solid-state low-power any color “Nixie Tube” would be!

The basic idea is that you position an LED at the edge of a piece of acrylic that has a pattern laser-etched into its surface, and the LED lights up the pattern. Long ago I’d realized that a stack of 10 laser-etched digits with an LED to light up each digit might have the same visual charm as a Nixie Tube, and the Plexitube was born.

I’m pleased with the way the project turned out.  I’ve put the software, circuit designs, and illustrator files up on github. I even made a short video of one of the clocks in action.  The project has even gotten some attention from Hackaday and won this Reddit unconventional clock competition.  Thanks a lot guys!

owlEyeElementsBackAndForthSmall

At the time it was unclear if light bleed between the layers would make the digits hard to read, so I sat on the Plexitube idea for a long time waiting for a project that could use that kind of display.

Then I went to work at a new company, and I had to spend an entire day listening to benefits summaries and corporate on-boarding. To pass the time, I started to do some sketches of an owl made from only two pieces of wood. I used my Swiss army knife to cut my co-workers’ name tags into owl prototypes. I really liked the design, and I thought it would be perfect for an owl-shaped clock with Plexitube eyes. Would this be this year’s Christmas Project?

I can’t really start a Christmas Project until after the Halloween Costume builds are done, but this project couldn’t really take shape until I’d at least tested the viability of the Plexitube. I figured if I just spent one evening laser-etching a digit stack and holding it over an LED, I could figure out if the displays were going to be an unreadable mess. If it failed, I could pull the plug on the owl idea before they got out of the paper prototype stage. So I spent one of my Wednesday nights making a prototype stack.

VeryFirstTestOfPlexitubeThe prototype stack had a lot of issues. The back digits where hard to read, there was a lot of inter-digit light bleed. I really couldn’t say for sure whether this was going to work. That’s pretty much the worst-case scenario for a make-or-break prototype. Really, I should have just stopped then, but I couldn’t stop thinking about the nice owl shapes.

The Impossible Project

Halloween came and went and I needed to decide. I even went so far as to do some prototypes of an alternative project that was much simpler, but I could tell that the owls were the ones that wanted to be made. I’m usually pretty careful planning one of these projects, and never before had I taken on one that had so many BIG unknowns. I’d never worked with surface mount electronics, never bent wood to such small radii, never designed a PCB with a lot of exact physical layout constraints, and never used an in-circuit programmer. I decided to go for it, but I knew I’d have to get first-time-success-lucky on a number of things, and I told my coworkers that I did not expect to succeed.

Two months and counting

realTimeClocksTime to make a lot of quick choices and order stuff from China. I chose the popular Neopixel surface mount LED as my light source. They could be any color and all 40 of them could be controlled using just one pin from my controller. I decided to go with the ATMEGA328p, which is the same chip in an Arduino UNO. I was building 6 clocks, so I’d need 240 LEDs. I ordered a reel of 500 from China, along with some surface mount capacitor and resistor assortments, photo resistors, and some DS3231 real-time clock modules with battery backup. Ordering things from China is very cheap, but it can take a few weeks for the stuff to show up, so I had to get that moving quickly.

Now ordering printed circuit boards from OSH Park takes something like 10 days, so I really needed to get that in the pipe. If the first set of boards were a complete blowout, I could still get a second order in, but I had to hurry.

lightGuidesCloseupThe LEDs I was using are much fatter than that 1/16″ acrylic layers I was using, so each layer needed to have a sort of integrated light guide leg that would stick out and sit directly above the 3 tiny color chips inside the LED. The alignment had to be exact. So I measured an 10-layer alternating stack of acrylic and black card stock to get the exact spacing, and then I had enough info to begin laying out the PCB.

 

 

OwlClockPCBTopI used Eagle CAD and finally had to spring for the non-free version so I could work with more than one page of circuit. I had to use some tricks with the Grid to get all the LEDs laid out in the exact right locations. After a full weekend of fighting with Eagle, I had something I could send off to OSH Park. I also quickly ripped one eye segment out into another file and ordered 3 small “test boards,” so I wouldn’t have to do my first attempt at reflowing a surface mount board with one of my giant and owl boards.

Then it was back to working in Illustrator on the design for the acrylic digit layers, black card stock separators, etc. I customized the digits of a font to make them slimmer. All the digits obstruct one another, so I wanted something that was lovely, but was mostly empty space so other digits could shine though. I also did some tricks like make the zero (which is in the back) a bit bigger/bolder so it would still read well though all the other digits.

Secret Symbols

Now on a clock there are 4 digits, but not every digit needs all 10 numerals. Heck, the tens of hours digit only really needs a 1. That leaves 9 layers for other special non-digit things. I could, in theory, have put some extra digits in the back of the tens of minute digit since it only goes 0-5, but I decided if I was going to be showing other info in those lower digits, it would be better to have all the digits there. I also decided to keep the 2 in the hour-tens digit so I could support 24-hour time in the future, and show a full year like 2016, etc.

I wanted to show the phases of the moon, sunrise and sunset times, moon rise and moon set times, etc. I used 6 of my 8 free digits doing the arcs of the moon. Because all the layers are at different depths, I staggered them so the arcs actually make a 3D sphere shape with the middle most arcs at the front. That left me with 2 layers. I used one for a sun outline that could be used along with the arcs to show things like the equinoxes/solstices.

The Magic Eye

That left me with only one free layer, which I used to add the outline of an eye. I realized that the arcs could be used to animate a slit-pupil eye looking back and forth. Of course I needed that! My owls eyes have eyes?! Yes … yes they do.

Plexitube Assembly

eyeElementBeingStackedEach eye element can display two digits, and they are laboriously assembled by stacking 20 digit layers and 20 paper masks on 4 brass pins in careful sequence. Thankfully, the digit layers were fairly easy to keep track of because they already had digits etched into them! Each acrylic layer has to have its protective plastic peeled away, and its etching scraped and dusted. Because the pins are press-fit, I had to carefully push them down on the pins without cracking the 1/16″ acrylic. The first stack took me 2 hours to assemble. My finger nails were frayed from all the plastic peeling and I had 11 more elements to make. What had I gotten myself into?!

eyeElementBack

First Reflow

solderPasteStencilingFinally the owl boards came! I had also ordered a solder stencil from OSH Stencils. When making a board like this, the basic process is a bit like silk screen printing. You position the PCB under a stencil and squeegee solder paste though the stencil holes onto the board. Then you place all the itty-bitty components onto the board with tweezers. Finally you oh-so-carefully put the board in an oven and heat it up until the solder paste melts and the parts all snuggle down exactly into place via surface tension. A while ago, I had built a special computer-controlled toaster oven in order to do just this process, but I had never used it!

intoTheToasterI kept waiting for my test boards to show up, but eventually I gave up and decided to do my first reflow on one of my giant and indispensable owl boards. I populated the board, put it in the oven, and pushed the button. Then I held my breath as the oven went though its 3-minute cycle. Success! The board came out looking perfect! It looked like something totally commercial, not something I’d made with tweezers and a toaster oven. MAGIC! Surface mount is awesome. I’m never going back!

fiveOfSixBoardsForOwlsOk, so the board looked like it was all soldered up, but would it work? I hooked the LED chain on the board up to an Arduino UNO (remember how those NeoPixels can be driven by just 1 LED?) and some quick code showed that all the LEDs were working! I blinked each one red-green-blue to test and they passed with flying colors! *phew*

owlClockDigitTest54Now for the real question: would the digit display actually look good or was the whole thing going be two months of work for an unreadable mess? I wrote some code to cycle though the numbers and positioned the eye module over the LEDs. It sort of worked, but it wasn’t great.There was quite a bit of cross lighting between digits, especially between digits 1 and 2.

I was extra sad I’d left that 2 in the hour tens digit. No one wants to look at a clock and not be able to tell if it’s 11:14 or 22:14. Something really needed to be changed. But what? I did, however, decide to get my second round of PCBs made. OSH Park sends out 3x boards, so if I wanted 6 by Christmas, I’d have to order the second round pronto.

OwlLogoI spent an evening designing a nice owl icon to put on the second round of boards, added two regulator bypass pins, and then sent the thing off. No time for anything fancy. It turns out the icon was a fail.  Even though I followed OSH Park’s guide lines it did not render properly.

 

Eerie Is Good

plexitubeCloseupOne thing I did notice while I was running that test is that although the digits were not yet crystal clear, the whole thing had a very eerie feel to it. It was almost as if I couldn’t quite tell what the heck kind of technology I was looking at. It sure didn’t look like LEDs. The layers of acrylic have a wonder full “hall of mirrors” effect on the lit segments.  I also noticed that the light bleeding off the tops/sides of the eye element were kind of hypnotic to watch go through their sequence. I had originally planned to cover the elements with a ridged copper cylinder segment, which would have looked steam punk, but not as strange/cool as that bleeding light. I decided to leave them uncovered.

Back To Body Work

Now that the boards and the eye element design were mostly settled, I had to get back to figuring out how to design the bent body of the owl. I did a second pass of designing the body in cardboard. I knew that trying to bend 1/8 plywood into a loop maybe 3 inches in diameter was going to be tricky and might be impossible. In a recent build, I’d used laser “kerf bending” to make it easier to bend curves in thicker plywood. Could I take that to an extreme? MicroKerf Bending™? I tried spacing the kerf cuts .1″ apart, cutting almost all the way though the plywood. The results where a satisfyingly bendy piece of wood. Still the owl has some very wide sections at the top of his eye arches and those were still quite stiff. Too much variation to be able to bend into a loop.It would have been nice to write some sort of script that would space the kerfs closer/wider based on the overall width of the piece, but I had to settle for just doing a few different spacings by hand.

owlBrowClampThe brows above the eye were delaminating when I’d apply the bend. That was bad. I fixed it by pre-sanding the upper layer thin in those areas and by putting a few little spring clamps on those edges during the bend. That solved the problem, but all these iterations on the body design were burning up time at a crazy rate. Would I make the Christmas deadline!? Here I’d been thinking I was saving time by having most of the owl form come from just one piece. So wrong.

Steaming and Clamping

owlInClampingJigI built a clamping jig out of a big board and carved away clearance for the owl feet. I’d steam an owl body in a pot on the stove and then bend it with my gloved hands whilst racing out to the garage to clamp the body around the face in my special jig. The first time I did this the face of the owl split in two! Yes, when the body is looped back on itself and clipped tail to feet the forces on the face are nice and balanced, but while you’re bending that around the forces on the face are actually pretty big. So I changed my clamping jig so it would support the face during the bend. Finally, it worked!

boardInOwlTestI had a lot of other little issues. I had to add some “foot prop” pieces so I could have a way of evening out feet after the main clamping was done. I thought I’d be able to adjust the owls stance by adjusting the tail angle, but a sort of scissoring action made it so any amount I pushed up the tail also pushed up the feet, canceling out the adjustment. So the owls look down a little bit more then I’d like. That’s okay though because they like to nest up high.

owlsOnTheClockFaceI wish I could have used 1/8″ mahogany plywood. Then I wouldn’t have had to deal with staining the outer body. However, that’s not something I can get locally so I was stuck with stain. I hate stain. I tired pre-staining, which gave nice crisp edges at the stain boundaries, but that made the gluing a lot weaker. I tried post staining with with pre-clear coating areas to try to reduce bleeding over, but it still bled some and required lots of awkward sanding to fix. If I had it to do again, I’d try to get hardwood ply. I did eventually get them all glued and stained.

The Secret Sauce

secritSauceUnderSideOfEyeI’d been thinking about my eye element problems. How could I improve the contrast? I already had black card stock all over the place blocking as much light as I could. I realized that as tight as the fit was around the card stock, there were still micro gaps, and the light leaks I was seeing were probably coming right up from the LEDs and into the clear bottoms of the other segments. I decided to use a small brush to paint some black acrylic into those areas! EUREKA! That fixed the problem entirely and now the displays looked great.

Christmas Eve

owlClockInFrontOfTreeIt was Christmas Eve, and I was still clear-coating owl bodies. Applying wood finish on Christmas Eve is par for the course for me. The big issue was that I was still driving the displays from a separate Arduino and hadn’t fired up the on-board computer at all. I spent a while reading about fuse bits and fighting with boot loaders, and fiddling with Arduino IDE config files. Had I made some mistake with as-yet-untested parts of the PCB? Could I get lucky one last time on this “impossible” project? Yes! At last, I was able to program the chip on the clock board, get the real time clock synced with Greenwich Mean Time, and put enough code in the clock that it could actually display the time! The clock could go under the tree.

Software in the New Year

Early on I had decided to punt on all but the most basic software until after Christmas. I had pages of ideas on fancy software features, and I knew I’d have enough trouble just getting the things physically built by Christmas. This was going to be a Christmas gift with an eventual “firmware upgrade” gift chaser.

owlSimulatorExplodedViewI knew there was going to be a lot of software, so I wrote a iPhone owl clock simulator to give me an easier platform to develop some of the code. I had been reading Jean Meesus’ Astronomical Algorithms, and I wanted to have the clock not only show the phases of the moon, but be able to display sunrise/set times and moon rise/set times.

I had included a light sensor on top of the clock so the clock could dim a bit when it was in the dark, but it could also tell if your hand waved over the clock and maybe then it would cycle though showing the sun going though sunrise colors while showing the sunrise time and the show the sunset time while cycle though the sunset colors.

Color Picking the Old Fashioned Way

colorPickerWithThreePotsAndUnoI really wanted to use nice colors in the clock, but just choosing 3 numbers for Red/Green/Blue doesn’t tell you what those are going to look like in the final display.  I needed a way to search for good colors.  So I made a super simple color picker by hot gluing three potentiometers to a board. I used an Arduino UNO to read the three RGB values and display the color on  a jury rigged LED + acrylic digit. Go Go gadget gaffer’s tape! The program would print the values out to the serial monitor.  That way I could find just the right pink by fiddling with the knobs and then write down that RGB triple from the screen.   I used that to make a whole pallet of colors I liked.

The Trouble With Doubles

The big problem was that most of the Astronomical Algorithms need double precision math. The solar system is big and you need the precision, but the Arduino tool chain doesn’t have real double precision math. I spent a while (stupidly) writing a math lib that did approximate double precision math using two single precision float values based on this paper targeted at GPU computation with floats. I did get the math working, but to my horror, I discovered that the code it produced to compute the equinoxes/solstices was so huge that it didn’t fit into the 32k of memory on the ATMeg328p. That was a huge waste of time. I did, however, use the code to generate the next 100 years of solstices and equinoxes and compress them down into just 100 bytes of Progmem, but the sunset/sunrise times were doomed. I went back to some still usable moon calculation code so the clock can show the current phase of the moon.

Then I wrote a lot of silly features. On the clock recipient’s birthday, it displays in their favorite colors. (And on their kids’ birthdays, their kid’s favorite color, etc)

I wrote all the code to set the time/date/gmt offset with nice auto repeat ramp ups and useful icons. (When you’re setting the month a sliver of moon shows, when you’re setting the day there’s a sun icon, etc) I even used the right arc of the circle to show AM and the left arc for PM like they were the first and second parts of a 24 hour clock face. Not that I expect people have to set the time/date much, but a clock needs to do that.

The clock counts down to midnight on New Year’s Eve and shows fireworks and a spinning golden globe at midnight. On JRR Tolkien’s birthday, the the eye of Sauron looks around and sometimes a golden ring spins and the digits are red and fade up and down like like a breathing beast.  etc.  I don’t want to give to many surprises away.

Needless to say, there are a year’s worth of Easter Eggs in the clock code, even on Easter.

Two Words “Optical Theremin”

photoresistorsWhen I was working on the auto-dimming feature, I wanted to have a direct readout of the light sensor, so I could fine tune a mass/spring system for the dimming rates. When I first hooked it up, I realized that with a much stiffer spring it was pretty neat to play with. You’d wave your hand over the clock and the digits would smoothly go up and down. It was kind of mesmerizing.

I was showing it to a friend, and when I started waving my hand around he said, “Wait, it has a Theremin too!?” and the Optical Theremin was born. I hooked that code up to the hue of an hsv conversion and now when you press the down button, you get one minute of “Optical Theremin” where waving your hands around changes the colors and numbers in a soothing and lovely display of Plexitube awesomeness.

It’s hard to stop writing code for the clock, but after the “Optical Theremin” feature, I started getting close to the memory limits and I decided to call it quits. It was time to give out festive springtime firmware upgrades! I had been trying super hard to have the code all done before the spring Daylight Savings Time change because people had clocks they couldn’t set! I only missed that deadline by a week. I blame double precision!

owlTrustBuidingExercise

Clarence was starting to think that perhaps this hazing ritual was going a bit too far…

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Angels and Devils: Making A Smoking Man Candle Holder

Second Sketch of Angel and DevilEvery year is build a big Christmas project.   Usually I get started on those projects right after Halloween, but this year I started way late.  At Thanksgiving, I was sitting out on my sister’s porch and  finally managed to sketch something that I liked enough to build.  The problem with such a late start was that I kept thinking, “I need to keep it simple, and depend more on excellent design rather than absurd complexity.”   This would have been great if I hadn’t eventually let the “keep it simple” part fall to the floor.

Devil SketchIn Germany, they have Räuchermänner (smoking men), which are little wooden figurines that have a small compartment to hold an incense cone. The burning incense smoke comes out of figure’s mouth.  I’ve always wanted to make one.   I considered traditional figures like a hunter, and wackier ones like a dragon, but eventually I decided it might be fun to make a devil with smoke coming out of his mouth.  A lot of German Christmas decorations have angels on them, so I thought a candle-holding angel and a smoking devil would make a nice contrasting pair.  I started some sketches and paper cut-outs, and I finally started designing the thing in earnest on Dec.  5th.   That was an epically late start.


I still had some 1/4″ mahogany plywood left over from the Egyptian labyrinth project, so I decided to use that for the devil.  This turned out to be a big mistake.   The devil wing design had very thin spars that would have been trivial to cut out of 1/8″ plywood.  If I had used 1/8″, the laser could’ve been cutting quickly enough that I wouldn’t have problems with the wood heating and catching fire.   Since I had committed to 1/4″,  I had to develop an entirely new technique where I cut the devils in three passes, using a syringe to put water into the cuts at each wing tip and pointy corners that would otherwise smolder during the subsequent laser passes.

Devil Parts On Laser Tail PitchforkThis worked, and it gave the devil an interesting burned look, but having to develop this technique burned a lot of my laser time. Christmas was fast approaching, and every minute on the laser was precious. I found myself sprinting back and forth to the bathroom with syringes of water.  Not good.  I also discovered that if you’re cutting multiple passes in wood, it’s best to orient the cuts so they are perpendicular to the direction of the compressed air blast at the cutting head.  Otherwise the compressed air can blow along the cut and fan any sort of smoldering wood you may have left in your wake.

Laser Cut Oak BaseI really do not like multi-pass cutting.  The wooden bases for the project were thicker than the devil wood, and I was able to cut them very, very cleanly in a single pass.  It’s oak, and the tiny holes you see are vessels that form in the spring.  You can see how they’re not blocked by sawdust and the radial rays are clearly visible radiating out from the center of the tree like spokes on a wheel.  I cut this at 300 pulses per second, and you can see the tiny grooves left by the pulses.  There is no charring or need to sand the edges.  It’s lovely, but I was careful not to have any thin sections or sharp points in the outline of the base.

Devil Smoke Hole MiterThe devil was hard to cut, and he turned out to be somewhat tricky to assemble as well.  I had to hand miter the top edge of the curved side pieces.  I also had to glue a paper smoke dam into his neck since the top of the devil’s body had to be airtight to prevent leakage of incense smoke from his neck.  The first two devils that I assembled still leaked a thin stream of smoke from that seam. In later versions, I suspended the assembled devils upside down and dabbed white glue down into the peak with a long stick to make sure the seam was sealed.

Devil Body Assembly Another way that the devil was much harder to assemble than the angel was the slanted back. The angle forced me to hand sand a bevel on the base. The curved sides made it tricky to attach the front since I needed to push the sides out to get them into the curved groove on the front face, but without disturbing the anchor pieces, and without knocking the bottom plate out of whack. So it was an exercise in white glue octopus wrestling.  If I applied too much clamping force, the slanted back would cause the base to come squirting out and whole process would begin again.


Devil Heads
By the sixth devil, I was quite adept at this, but the first few had some unenviable gaps, which thankfully were not visible from the outside.  I like the way the devil’s beards came out.  They’re the hidden shape of a swooshing bat.  I did some hand wood burning on the horn segments to make them a bit more interesting.  The biggest disappointment with the devils was that when I finally applied the clear coat, the contrast between their faces and the facial hair dropped unexpectedly, and by then it was far too late to switch to black walnut or something else.   

Devil Hands To GlueI like the way their gnarled little fists came out.  Complete with thumbs! They’re made from three stacked segments glued together and then glued to the devil’s front.  Here you can see the pieces ready for some dabs of glue.

The first two devils I cut had some burning on the inside corners of the belly door.   This was because I hadn’t realized those corners also needed some water injection.  Later devils didn’t have that problem, but to cover the first two I hastily designed some little feet  I could glue on over that area.  This design change is why you don’t see any feet in my original sketches.

Devil DoorPartsI also had to punt on having a tiny flame theme around the incense holder because there simply wasn’t enough room, so I switched to a simple ring.  The copper pan that the incense sits in was cut from a 1/2″ copper tube cap.  I used these both for the incense cup and the candle holder.

I chucked a piece of 1/2″ copper pipe in the lathe and used that to hold the end caps so I could cut them off at two different depths with a parting tool.  The only annoyance was that removing the remaining ring of metal from the 1/2″ was hard to do.   The parting operation squeezed the copper rings so they were hanging onto that pipe for dear life, and I had to pry them loose with a giant flat-head screwdriver and a lot of elbow grease.  Good thing I only had to  do that twelve times.

Devil Door In PositionOnce the feet were on and the door was done, the only thing left to glue on the devil was the head of the pitchfork.  I always glued that on last because it’s cut from thin sheet, and there’s no way to orient the grain of the wood to make them strong along their whole length, so they’re quite fragile between the tines where the grain cuts directly across those narrow sections.

Angel Going TogetherThe angels were comparatively simple to assemble. I carefully positioned them on the maple board so the maple’s figure would form the folds of her skirt and sleeves.  I used different wood for her face, neck, and hands.  I used a layering effect with  the hair to try and keep her head from looking too much like 2D extrusion.  I was going to try layering the area with her ear back one layer to make it even more 3D, but that would have required some more hair fragments, and a bit of iterating on the laser to get the ear size just right. Eventually I punted on that plan. So her head is a bit more of an extrusion than I would have liked.  Oh, well.

Angel Wing Mount ClampI did have to have a slightly tricky clamping rig to glue on the top wing mounting bracket.  I used a laser-cut scrap to match the shape of the bracket and make the clamping possible. Then I used some clothes pins to keep the scrap aligned while I tightened up the other clamps.

The only materials disaster I had with the angels was that the 1/8″ plywood I used to make the wing spars was defective, and some of the spars had their topmost layer of wood just fall off. I had to re-cut a bunch of them.  I’d never had that happen before.  I used clothes pins to provide even clamping force when gluing the spar to the feather veneer.

Wing Parts Test Assebly   Wing With Clothes Pins

Glued Angel WingI had originally thought about using white paper angel wing feathers and black paper wing membranes for the devils, but when I was shopping for the figured maple board I used for the angels, I found some lovely dark figured veneer.  I realized it would look SO much better than black paper on the devil.  I already had the veneer I needed for the  angels, so after I’d sprung for the devil veneer, I switched the angel over and never looked back.  I’m glad I did.

One Winged AngelI did end up having to sand a slight bevel onto the very bottom point of the wings to keep them from clonking into the angels bustle, but other than that they were really easy to put together.  The wings are glued to the top bracket, but they are just slid into the bottom bracket.  That keeps them from getting pried off by differential wood expansion of the body and wings.


The only serious annoyance I had with the angels were their faces. A face is so important, and I’d really sweated the design. I ended up trying to keep it super simple. Just a few lines.  However, as I was assembling the angels, I realized that from a lot of angles the laser-etched faces were very hard to see.

Angel With Halo On Graphite Bleed face.Faceless angels are a bit creepy, so I knew I had to do something. For the first two, I used black acrylic and a fine paint brush to darken the lines after the clear coat had been applied.  That was a pretty ticklish operation to do on otherwise finished pieces. It was no fun at all. After that, I simply highlighted the face details with a mechanical pencil. That was nice and easy, but when I used a brushed on clear coat the graphite ran and gave their expressions a somewhat haunted look. I spray coated the last two angels, and their faces came out the best. Nice clear details from any angle.

Angel Face DownOne of the design details I’m proud of is that I wanted a little cleavage V in the front aligned with her hands, but I knew that would look weird on the back. So I positioned the wing mounting bracket so it neatly trims that off, making it look more like a normal dress back.

I wanted to make halos for the angels.  I went wandering through the hardware store to see what kind of rings or loops I could find.  I purchased a few different kinds, but eventually settled on some straight knurled brass lock nuts.  As the giant monolith of Christmas rolled inexorably toward me across my calendar, I decided to punt on the halos.  No one would miss them.

Boring Halo On the LatheHowever, during the Christmas break, I had a change of heart (and a  bit more time), so I decided to make the halos even though that meant giving out a few “halo retrofit” kits.  The alignment holes for the halos were in the original design, so adding them was just an insertion and a dab of E6000.   Simple pimple.  To make the halos, I used a boring bar on the lathe to machine the threads out.  No self-respecting angel goes out in public with a halo that looks like it screws on.  I then had to drill a tiny hole part way through the halo to mount a piece of piano wire.

Drilling A Halo HoleLuckily, I already had the tiny center drill for the job, and I set up a depth stop on the drill press.  Then it was just a matter of clamping and drilling the six golden rings. Four calling birds, Three french hens, Two turtle doves…  Wait where was I?

Halos DrilledHalos With Wires Glued

I used a bit of JB weld to glue lengths of piano wire into the holes.  I glued each wire to the halo at a jaunty angle so the angel would not look like she was balancing a book on her head at Angel Finishing School.

Outdoor AngleThe piano wire feeds down through holes in both the upper and lower brackets on the back of the angel, and a dab of E6000 cements  the wire to the bottom bracket in a slightly springy but tenacious way.  Then it was just a matter of mounting each angel on a base, and adding a candle cup made from another 1/2″ copper pipe cap.

The devil is mounted using T-shaped pins that pass through his floor plate and into matching holes in the base.  The angel is simpler.  She just has two pins on her bustle that align with slots in the board.

I managed to have two sets completely done by Christmas Day, and I finished up the other four sets a bit into the new year.  Overall I’m very happy with the way this year’s Big Christmas Project turned out, especially considering the late start.   I’m marking it down as a success.

Devil With Pitchfork

Devil Incense   Devil With Black Card Smoke

Angel Devil With Narrow Depth Of Field Angel Devil Two Shot With SmokeAngel And Devil Outside angelAndDevilWithSmokeSmall