Death of Rats, Mk. II

The Death of Rats has been our Halloween Decoration for a couple of years - there is actually an Instructable for the original version, which can be found here. Last year it suffered some damages, mainly due to cats gnawing on the chicken bones, and I decided to give it some TLC. And to make it more awesome. To get done in time I had to omit some of the things I had planned for Mk. II, but you can find them at the end of this Instructable if you are interested.

Those of you who are familiar with the Discworld series probably know what or who the Death of Rats is. To those few who are not "in the know", here is the short version:

There is Death, an anthropomorphic representation of the concept of death. He is a skeleton with long black robes and a scythe, the classic reaper. At some point, there has been some confusion about his status, and he was actually split up - there were reapers for every kind of animal, looking like skeletal versions of that animal. Death (the original one) managed to sort that out and round up all the other deaths. Except for two. The Death of Rats, as depicted in this Halloween decoration, and the Death of Fleas, who tends to travel with the Death of Rats.

If you want to make this, you should go by what you want and what you have more than by what I did. Nevertheless, here is a list of materials and tools I used, and it is by no means comprehensive.

Materials

• Black Cloth - for the robes. For Mk. I, I had dyed basic linen cloth to make it look more fantasy-authentic. You could also use fake black leather for a more martial look.
• Chicken Wire - to form the new superstructure, which is to say the shape of the open robes.
• Newspapers - to give the wire mesh structure strength (and something to read).
• Wallpaper Glue (and water) - to hold all the elements of the superstructure together.
• Grey Felt (slightly optional) - to go on the inside of the robe. I chose grey to make the inside a little lighter, although I am not sure that it makes that much of a difference over black. You do need something to cover up the newspaper pieces. Black paint would probably work just as well.
• Wood - for the base and all the bones (except for the skull).
• Bore Skull - for the Rat Skull.
• Hot Glue - to connect many of the pieces.
• Screws - to connect a few more pieces.
• (Spray) Paint - to color the bones. Initially, I wanted to prime the bones in white and then add a coat of ivory to them, but as it turns out, white on wood tends to look kinda like that already at some point.
• Stick - in lieu of a scythe. Kinda optional and/or variable.
• Mounting band - two pieces of roughly 25cm/10" long, to stabilize the stick.
• Electronic components - I had to rush this part, so I will not go into that much detail here. I used a
  • NoceMCU - with the Arduino IDE to run a
  • NeoPixel-like LED-Strip - and display a custom color palette using the FastLED library in its most basic form. Full disclosure, I also used
  • Wires - to connect things and
  • Clip connectors - to keep wires together.

Tools

• Pliers (and metal shears) - to cut and handle the chicken wire, and to bend the ends in on themselves to keep them together.
• Bowl - to mix the wallpaper glue in.
• Bandsaw - to cut and shape wood. The way I did this project, this was by far the most important tool. I used it not only to cut out bone shapes, but I also shaped them on there Jimmy-DiResta-style.
• Scroll Saw (optional) - to replace the bandsaw when all your blades have given out on you. Hopefully very optional for you.
• Miter saw - to cut wood to size and to create precise angles to connect pieces.
• Belt sander - to smooth over the bones and add a little more shaping.
• Rotary Tool with Mill Bit - for the more intimate shaping of pieces where the larger tools cannot cut it. Literally.
• Hot Glue Gun - to apply the hot glue
• Drill - to put in screws with in positions where a drill press might not get to.
• Forstner Bit - to drill a large enough hole for something the rat might hold. In my case, this would be the stick.
• Drill Press - Recommended for use with the forstner bit.

In my mind, Mk. I had two important features. His robes were closed and his feet and hands were made from chicken bones (think chicken wings). Those bones turned out to be a problem when cats decided that they were fun to play with and gnaw at. Which is the main reason for actually making Mk. II. But I also wanted to fix the robe, because what good is having a skeletal rat if you do not get to see anything but the skull?

So I took the old one apart, which, as you can see, consisted of nothing more but a wooden superstructure. The old robe was still in good condition, so it would find a spot in the new design. As it turned out, it was large enough to work well without any modifications.

Since I want the robe to be open it needs to hold its own in terms of weight. As such, I use wire mesh to make a sturdy base for it. I use metal shears to cut the pieces to rough size, then I bend them to a cylindrical shape. To make the top come together I cut into the material and bend the flaps over each other and use pliers to pull ene ends through the mesh to make them link together.

At this point it is hard to imagine how the finished robe will look like, let alone determine whether it will fit. But all that comes after this can be made to fit whatever the result of this step is, so that is not much of a problem. The only thing that cannot be altered is the skull. For that, I make a separate cowl piece, also from wire mesh.

Since draping the robe around the wiremesh superstructure will likely cause only headaches, and the shape itself is still pretty malleable, I want to stabilize is using newspapers and wallpaper glue. Maybe this technique is familiar to you from kids' crafts, and it works well to build up a sturdy surface that strengthens the wire mesh.

I tear most of the newspaper into strips, but you could also use larger pieces since the glue will make it eacy to fold them flat anyway. I try to add as many layers to the inside as I do on the outside. Since the whole thing needs to dry (it is a rather wet affair), I would recommend letting it dry through at least once even though you still want to add more newspaper, because in my experience the overall drying time will be less than waiting for all the paper to dry in one go.

Sincd there is little evidence that grim reapers wear a layer of newspaper under their robes - although it would most likely help to keep them warm - I add a layer of grey felt to the inside of the dried stand-up robe. I chose grey felt to make it less dark than black, reasoning that black felt would take away too much color when the rat is illuminated (eventually), and also make it easier to admire the bones when it is light outside.

Whether either of that assumptions is correct is up for debate. Using black would probably have made for a different effect, and since the bones are near-white anyway it would not have mattered much I guess. But this is how I made it, and for now, this is how it will be.

I also added the old robes to the outside and glued it to it just enough to keep it in place - mainly on the front. That allows me to put things in the back, hidden from view.

I take a board - actually a number of scrap slats glued together - and place the robe onto it to trace out a rough shape. I want it to extend a little further to the back, but I have enough fabric to cover tha up, too. I then cut out the shape on the bandsaw.

To add stability to the whole thing I add a long slat to the back, just behind where the robe would come in.I screw it in place, then I shread the second spine between the mesh-and-newspaper and the black robes. Here, the slat will be covered all the way up where the hood does the rest.

Allmost all of the bones in this version of the Death of Rats are made using the same techniques, so I will not go into details for every single bone but rather give you the highlights in the following steps.

This basic technique makes heavy use of the bandsaw to shape the pieces. I always start out by tracing a bone-shape on the flat side of the piece of wood I am using, and then cut it out. Then I flip the piece on its side and immitate that shape. Then I remove the corners by freehanding the piece. This is not as hard as it may look as long as you make sure to have the piece rest on the worktable and keep your fingers away from the blade. Remember that you can pull the piece the rest of the way to finish cuts.

Once the bone is reasonably round and shaped, I use the bandsaw backwards to "sand" the remaining edges off (Full disclosure, I picked up that trick from Mr. Jimmy DiResta). This is a good technique to know, but not entirely necessary since I am then moving on the belt sander for the final shaping and smoothing out of the bone.

Also on a general note, I used hot glue to connect bones to each other in most cases, and I did not bother keeping that glue hidden. If it ever comes up, I will explain it away as being cartillage. Also, I imagine that if I ever need to take things apart again, it would work quite well using hot air.

The feet are made up of two bones and the feet themselves, who would in reality be made up of a number of bones of their own. I admit that I could have added more details here, but I did not think they would get much attention. I cut out the overall shape, then cut between the toebones with the piece tilted in both directions, i.e. making tso cuts. It did not turn out too great because I did not hit the right spit both times. A vertical cut and then some careful shaping might have worked better.

To connect the bones I freehand the joints and cut flat spots where they meet the feet and the (upcoming) hip. The knee joint itself was a haphhazard thing, and did not work quite as it should because when I made it - on the bandsaw - I was planning it for the wrong angle. I was also limited by the nature of bandsaw cuts. In the end, I should have used the rotary tool mill bit that I used in the next step.

The hip serves both as connection for the legs as well as the base of the spine. It is also a fairly complex shape, and the bandsaw cannot do inside holes. To get it done without too much hassle I took two pieces of slat, clamped them together and sketched out the holes that need to go through it. This way, I can then take them apart and cut the shape in the bandsaw.

If you are using a different tool (like a scroll saw) you can do the hips in one piece, but I assume it is easier to come by two pieces of wood half that size.

To add a degree of 3D to it I then used my rotary tool with the aforementioned mill bit. Looking at the reference picture, I remmoved material at the front and ad the back of the vertical "columns" in such a way, that two appar to be further back then the other two.

I only glued mine together after the shaping, but I should have done it before, because naturally, they moved against each other as I clamped them and I had a few more edges to clean up. Then again, nobody will ever notice, really.

While you may think about rats what you will, they do need a backbone. A visible one, in addition to the one in the back. So I took a slat and added two 45° chamfers to one wide side, thinking that it would make it easier to attach the ribs in the next process (and it probably helped).

In the past I had considered other ways to make vertebrae - shaping them from foam with a soldering iron, or cutting single ones from wood and threading them onto a dowel. But that all seemed like too much work, and realism is a tricky thing when you are working with wood and not too much time on your hands. I mean, the feet are not realistic at all, but you can still make a guess at what they are supposed to be.

So I settled for a series of coves on the bandsaw to mimic a proper spine, up to where the ribs start. My last bandsaw blade broke at this point, otherwise I might have added a few more details, like a smaller chamfer in the larger ones, to approximate the vertebrae.

For the ribs, I take some smaller slats and start out by cutting them at a 22.5° angle on the miter saw. This allows me to put pieces together in an octagon shape, which is a pretty decent mix of circle and simple. I vary the length of the pieces to flatten the shape based on the room I have inside the robes as well as my preconceived ideas of what it means to be a rat's ribcage. For the connection to the spine, I adapt the angle to match the 45° on there,

All the pieces receive a roundover on the belt sander before I hot-glue them together. After which I sand over the corners again to make for a rounder rip experience. One of the costal arches did not quite meet up at the back, so I brike it apart again - which is one of the advantages of hot glue - and used it as two unconnected ribs instead.

The skull will rest in the cowl piece, but it needs some sort of stabilization to keep it there. I find an old hammer hilt that fits into a cavity on the back of the skull, then I drill two holes in the back spine to make a matching hole to stick it in. In the end, I get a friction fit, which is fine by me.

The tricky thing about the arms is that the new robes do not have holes for them. On the other hand, it would be pointless to shape arms from shoulder to hand, only to have them then covered with black cloth sleeves. So instead, I roughly cut the curve of the robe into two pieces of wood, then I screw them to the superstructure with two screws from the inside. I then drape the sleeves over the shoulders and attach them with a few drops of hot glue.

Connecting the arms to the shoulder pieces is a little tricky, at least if you want them to come out in a certain direction. For that, you need to take a good guess at the compound angle, which is the miter angle and the tilt of the blade on a tilting miter saw. You can also do the same on the bandsaw by tilting the table and angling the workpiece. I recommend trial and error for this until you have two piefes that, when attached to the shoulder, point in the right direction.

As you might have seen in the video, I shaped the first arm before cutting the compound angle. This way I had no controle over which way the hand was oriented. For the second arm, I made the cut first, then shapd radius and ulna accordingly (on the scroll saw, but a bandsaw would work just as well). Actually, the first arm I made will not see any use in this iteration of the rat, so let's move on to the second one.

The second arm was supposed to hold the scythe, which is of course a mandatory prop for a reaper. Due to time constraints, the scythe itself did not happen, so it will now hold a stick instead. With the arm angled in the right direction, I needed a hand.

I first took a forstner bit to drill a hole into a piece of slat. That hole needs to be large enough for whatever you want the rat to hold to fit into. Then I sketched the fingers going around that hole and cut them out. To separate the fingers I again used the mill bit, because any kind of cutting would most likely lead to the hand disintegrating along the way. I also use it to shape the connecting faces for the arm, and connect them both using hot glue.

The way I made the hole I could fit the strick through it with some twisting and turning. To keep the stick from falling over or, worse, toppling the rat, I used two pieces of mounting band screwed to the butt end of the stick and connected to the base to keep it somewhat stable. Those bands do not look that good, but I hope they will blend in to the ground.

For the lighting, I use an RGB LED strip with the ability to control every single LED (which is so awesome if you stop and think about what technology can actually do these days. Sorry, but all the possibilities...). I cut it into strips. Two for the insides of the robes and one for the cowl. I actually wanted to have light in the sleeves as well, but the way the cloth hung down I did not see the point.

These strips are connected to an Arduino Uno via wires leading to the back, all hidden under the robes except for the mandatory power cord. If you want more details on the programming and developement and the getting-this-to-work-at-all, you can find that in the next step. Otherwise, skip one ahead for more ideas for the future.

I used the Arduino IDE for programming, and you can find a number of good Instructables about that here so I will not go into that. I wanted to run the code on a NodeMCU, which is a wifi-module turned full Arduino, but for some unknown reason, it stopped working late in the developement procees. The code would run for a number of cycles, then reset. At the last minute, I replaced it with an Arduino Uno and everything worked out fine.

For the light show I used the FastLED library which allows you to easily get the most out of your neopixel-like LED-strip. I loaded the "Color Palette" script from the library's example files which is a cool way to see what the strip can do. Then I cut away what I did not need, and ended up with a single self-defined palette using the colors aqua, blue and grey.

I also added two single RGB LEDs to the skull to act as the eyes, which were the only part of the old rat that lit up. I tried to use the same code that ran the original eyes, but again, due to time constraints I just set them to a permanent bright blue for now. The original idea was to have them to slowly vary in brightness with the occasional blinking. Maybe I can still add that feature this year.

For those of you who care for such things, here is the complete code:

There are a few physical things that I wanted to add to the rat but did not manage in time. Most notably is the scythe, which is what the wooden stick should have been. The Mk. I had that exact same stick with a piece of plastic cut in basic scythe blade shape spray-painted and hot-glued to it. but it came apart and frankly, I wanted something better looking for Mk. II.

My plans went from an actual old metal scythe blade (too heavy, not to mention dangerous) to a see-through one made from a thin sheet of transparent plastic. I had the idea to make it light up to give it an ethereal effect, and my current idea is to use two pieces that connect at the blade and separate slightly towards the outside to make for a better light effect - which means the scythe would also receive some LEDs.

The other, less obvious omission is the hourglass. The first rat had one made from two acrylic teardrop shapes with a grid of hot glue added to them for support and decoration. It did not look that good, though. For the next version I am pondering a more classical design with a wooden frame around it. I still might use the acrylic shape because it is the easiest way to get something see-through. but I will probably paint it with swirls of color. I also plan to make it light up at some point.

One idea that the Mk. II design really lacks is a motion sensor so that it only activated when someone is actually close enough to appreciate it. That would also save a bit of energy. It would probably trigger for the odd cat, too, and even for leaves in the wind, but that would still be better than having it run around the clock - especially during daytime.

Another similar idea is to use a proximity sensor. I actually had this part set up on a breadboard and integrated it in the code at some point. It would take the distance value of the sensor, (calculate the average over the last five measurements to even out spikes and errors) and change the color palette used from blue to blue-yellow to red-yellow as someone approaches. It made for a cool effect, but I did not get to where it would have blended the colors or run smoothly.

As I mentioned in the last step, I want both the scathe and the hourglass to light up, too. That would, of course, require additional LED strips on separate pins, and allow for additional colors and effects.

Another idea that has been drifting through my mind, and that is actually both physical and electronic, is to make it move. Just imagine a rat that would look at someone approaching it, or at least turn its head. It could open its mouth and speak, and turn the hourglass if appropriate. The scythe would flicker to life - that is hoping that it would not be too visible in the dark, to begin with - and light in the hourglass would flow downward like sand.

The main problem with making it move is that it would require some heavy physical changes, especially for the head. For now, I will leave that on the drawing board. If only I had started earlier to get this done...

Thank you for checking out my Instructable. I hope you enjoyed this build, and that is inspired you to make something yourself (don't forget the "I Made It!" option). Let me know what you think in the comments, and I'd appreciate your vote in the Halloween contest! Also, you know, sharing is caring...

Thanks again, and no matter what you do, remember to be Inspired! (And have a happy Halloween!)