Intro: Benzene Molecule Wooden Fidget Spinner
I work in an Organic Electronics lab as my day job. When I tell people this, I think they are often confused and assume I do some weird experiments on cyborg mice or possibly grow electronics without GMOs, pesticides, angry thoughts, etc. However, the word "organic" here is used in the chemistry sense, in which it assumes chemical compounds with the element carbon. "Organic Electronics" is the field of solid-state physics that studies organic compounds that have specific (and hopefully useful) electronic properties that may be used for things like solar cells (organic photovoltaics), lights (organic light-emitting diodes), or transistors (organic thin-film transistors).
I also have two young sons who both are mildly obsessed with fidget spinners (who isn't nowadays?). So, I decided to try my hand at making an "organic electronics" inspired spinner! I ended up making two different wooden spinners: one based on the fundamental organic molecule of Benzene (which is a hexagon of carbon atoms) and another based on a molecule of Triphenylene. I made these in two very different ways, so I decided to split them into separate Instructables. In this one, I'll show you how to make the one based on Benzene (https://en.wikipedia.org/wiki/Benzene).
Step 1: Materials and Tools
There are many ways in which you could go about making this fidget spinner. Of course, my way is the best way and you should do exactly as I say. If you don't feel like being cool like me, go ahead and do it however you want.
List of tools I used:
- Clothes iron. Some people may have these sitting around their house to take wrinkles out of their clothes. Ours seems to be used to prevent the dust from collecting on the shelf it sits on.
- Access to a laser printer. This is necessary for the type of print transfer we'll do, but the same effect can be accomplished with a steady hand and a permanent black marker.
- Scroll saw.
- Drill press.
- Drill bits: 1/4", 5/16", 7/8", 1-1/4" hole-saw.
- Coping saw.
- Files (round and half-round).
- Bench vise.
- Sand paper.
List of materials I used:
- 1/4" wood at least 4" square (enough for two of these). I used lauan hardwood plywood since I could get it from Lowe's Home Improvement ~$6 for 24" x 48" https://www.lowes.com/pd/1-4-in-Lauan-Plywood-Application-as-2-x-4/1000068895 (you can make a LOT of fidget spinners with this sheet!)
- 1/4" wood dowel.
- 5/16" wood dowel.
- Ball bearing. I used the common 608 bearing with inner diameter 8mm, outer diameter 22mm, and width of 7mm. You can use whichever you want, but the hole will be different. I stole mine from my son's fidget spinner since they're just there for weight.
- Magazine paper.
- Parchment paper (optional). This will be used to protect the iron during the print transfer.
- 12 pennies or similarly sized metal discs or washers (used for weight).
- Spray Lacquer or wood wax (something to protect the wood).
Step 2: Draw It Out and Cut
You'll need to cut out two regular hexagons with a distance between two opposites sides of 3.5". I drew the shape using a straight-edge and a compass, but it would have been easier to have transferred the template from Step 4 and would shorten the number of steps.
Start out by getting your wood pieces with a width of 3.5". Since I used the 24" x 48" plywood, I just cut a strip of width 3.5". Draw a 2" radius circle. This is a close approximation of the size of the transcribed hexagon. Draw a straight line down the length halfway the width of the board (1.75" from each edge). With your compass still set to 2", pivot it on the intersection of the circle and the straight line and mark where a new circle would intersect the original circle. Repeat this by pivoting on one of the new intersections until there are 6 intersections that transcribes the hexagon. Connect the dots to define the hexagon. The top and bottom of the board will already be two of the sides.
I found it easiest to set my miter saw to 30 degrees and cutting the edges out with that. Otherwise, you can use your favorite cutting method, such as scroll saw, band saw, hacksaw, coping saw, well-placed karate chops, etc.
Do this again for the 2nd piece. Draw a 1.5" radius circle centered on the hexagon along with diagonal lines that join opposite corners. We'll use the intersection of the diagonals and the new circle to drill holes in the next step.
Step 3: Add Weights
You'll see in the pictures that I cut 3/4" holes into the corners of the hexagons. These are to hold pennies. You can use any other coins if you want, but just use the appropriate spade bit. I used the spade bit so I could drill partially down and keep the bottom of the hole square (you could use a forstner bit instead). However, this still requires the point of the bit to make a hole all the way through, so I clean that up afterward by drilling a clean 1/4" hole and plugging it with a 1/4" dowel that is glued in. I drilled the pilot hole for the spade bit at a radius of 1.5" from the center (although, you can put them wherever you wish) and in line with the corners.
Apply glue to the interior of both hexagons, but don't bother putting any in the coin holes. Apply enough glue to completely cover the mating surfaces (but don't overdo it). Remember to put your pennies in the holes. I made the holes deep enough to put one penny in each side, you'll just stack the two on top of each other as you assemble it all. After the pieces are in place, add clamping pressure. After it's dried, cut some small plugs from a wood dowel and glue them into the holes above the pennies. It's OK if the plugs are a little long since we'll just sand it down anyway. Let the glue dry and sand everything down to smooth.
Step 4: Print Design
A laser printer uses a plastic-based toner pigment powder instead of the liquid ink used in typical ink-jet printers. The toner powder is transferred to the paper and heated to melt and fuse the pigment into the paper. This is why the paper is always warm right when it comes out of a copier/laser printer. We will use this property to transfer the toner from the paper to our wood. This will help us for both defining the template to drill the wood for the bearing (you could have done this in the first step to define the edges of the hexagons instead of using the compass and straight edge. In hindsight, this would have been the better way to do it.) and to decorate it to complete the "Benzene" theme.
You can use regular printer paper, but I have found it best to use a glossier media such as a page from a magazine. I simply found a magazine sitting around the house and ripped a page out of it. Sometimes some of the print of the magazine transfers as well, so it may help to prep the paper first. We will transfer our image using the heat from the clothes iron. To prep the magazine paper (assuming there's some graphics/text already there), I pressed the magazine paper up against another blank sheet of regular printer paper and pressed the hot iron against it. If any of the magazine print is prone to come off the page, it should do so now instead of onto the wood. To protect your iron (unless you want smears of random ink on your clothes), place a sheet of parchment paper between it and the paper. Place the magazine paper into your laser printer's paper feed and print the attached template. Cut out a single template and place it on your wood, design side down, so that the entirety of the design is on the wood. You can use a piece of masking tape to keep it in place if you wish. Press the hot iron onto the template with the protective parchment paper in between. I used a setting somewhat in the middle of the temperature range, but you can experiment with whatever works for you. Make several passes with the iron, making sure to get the whole template hot. It's best to press with a decent amount of pressure which may be helped by using the tip or edge of the iron. The template should be sticking to the wood. Although you can try to peel the paper off now, I suggest not doing that yet. It may still pull the toner off with it. It seems to work well to get the back of the paper wet with water and then rub the paper off. Do this until all the paper is removed, adding water as needed.
Do this for both sides.
NOTE: The wood will be HOT! Be careful when handling both the iron and the wood. You should be mindful of the surface you are doing this on to make sure it is tolerant of the heat. Also, with the combination of both the heat and the water, the wood may have a tendency to warp. Simply press it against another flat piece of wood or set it in the vise between a couple blocks to make sure it cools/dries flat. You can alternatively use a product like Mod Podge to transfer the print to the wood instead of the iron.
Step 5: Drill Out the Bearing Hole
The template includes a convenient crosshair to line up the central hole for the bearing.
I used a 7/8" drill bit for the central bearing hole since I used a 608 bearing. The bearing is actually 22 mm while 7/8" converts to just over at 22.225 mm. The whole will be a little oversized, but I just wrapped the bearing in a layer of electrical tape (I'll go over that later). You could instead use a 13/16" drill and then enlarge the hole with a small drum sander or round file. I used a spade bit and the hole turned out fine. I'm sure a forstner bit would be somewhat cleaner. I'd wait until later to put the bearing in.
Step 6: Make the Finger Pads
I used a 1-1/4" hole saw to cut out a couple discs of wood. I decided to add a little fender to the discs to keep them separated from the bearing and only touch the inner race. This could be done in a lathe. Even though I don't have one, it didn't stop me from using other tools in ways they weren't intended. So, I clamped one at a time on a machine screw with a few nuts to tighten down on it. This was chucked into my drill press. I clamped a coping saw upside down in my drill press vise. With the press spinning, I slowly brought it down on the eagerly awaiting saw blade and used it to "face" the disc and leave the little ledge. I used a file to smooth it out a little bit and better define the ledge.
I took the two discs and enlarged their holes with a 5/16" bit, which corresponds with the wood dowel that is just a little smaller than the inner diameter of the bearing. I pressed the dowel into the discs and dry-fit the bearing to make a sandwich of them. This let me know where to cut the dowel off. After marking the cutoff location and dismantling the spinner, I cut the dowel to size and glued it to one of the discs. If you're like me, you might shy away from commitment (don't tell my wife!), so the spinner works fine by leaving the other side as just press-fitted onto the dowel. You could also counter-sink one of the pads and drill a pilot hole in the dowel for a small screw to hold it together (in my experience, this screw starts to work itself loose, so I'd go with just press fitting). You can then remove the finger pads and clean out or replace the bearing when needed.
Step 7: Putting It All Together and Cleaning It Up
As I mentioned before, the 608 bearing is too small to make a tight, press-fit into the 7/8" hole. So, I did one layer of electrical tape to fill in the gap. If you line up one edge of the tape with the edge of the bearing but let the other side overhang, you can use that to help pull the bearing through the hole and you should only have to trim one side when ready. You should be careful to not let the tape touch the ball bearings or the races so it doesn't leave a sticky residue that will slow down the bearing.
When in position, you can trim off the excess tape from the bearing. The dowel for the finger pads will need a small amount of tape as well. I found that scotch tape is a little thinner and gave me more precision in adding thickness than the electrical tape. In the end, either will work fine. Press the pads together. The spinner is now functionally complete. I sanded down the dowel to make it flush with the pad. You should protect the wood. I used some wood wax, but you could also use a couple coats of spray lacquer to protect the spinner part. If you do this, you'll want to remove the bearing or tape it off to keep the lacquer from gumming up the bearing. Have fun fidgeting and be sure to look up some of the science behind Organic Electronics!