Introduction: Roblocknics - Magnetic Wooden Robots

I make these fun toys for etsy using the basic building block of human existence known as the 2x4. Now I'm going to show you how to make them yourself!

These "robot blocks" use magnets to hold the parts together - and creative decoration to make them beautiful.

There are some things you need, so:

Parts List

  • (1) 2x4 - You only need one to make several. Get them at the hardware store, laying around the yard, or wherever. 2x4's are everywhere!
  • (10) Rare Earth Magnets - Super strong magnets for the joints to connect. I use quarter inch. You can use any size as long as they are strong enough to stick together. Regular magnets are not strong enough. And, just remember your drill bit will have to match in diameter. And yes, we use very strong epoxy so they won't dislodge.
  • 5-Minute Epoxy - The uber sticking glue for the magnets. You can't pry them out with a crowbar after sticking them in with this stuff.
  • Forstner Drill Bit - Again, make sure the drill bit matches the magnet size (I use 1/4" for both). A regular drill bit can work too if you fill in the divot to flat - but a forstner makes a nice flat hole to start.
  • Gorrilla Glue Gel - This is a superglue for attaching googly eyes and other features.
  • Acrylic Paint - Matte finish is best for gluing too. As far as brand, take your pick. I buy what's on sale!

Optional List (for polymer clay beautification)

  • Silcone Gear Mold - press polymer clay into these to make cool gears to attach.
  • Polymer Clay Multi-Pack - Multi-pack is good for two reasons: 1) Need lots of colors. 2) Only need a small amount of each.
  • Sealer / Finish Coat - something that agrees with acrylic paint to protect the paint (not oil based poly - been there, melted my finish with that.)

Other Random Stuff

  • Various grit sandpaper
  • Small paint brushes
  • Little things around most workshops I'm forgetting that will be mentioned in the steps ;)

Ok, now we have our supplies in order, lets make some robots!!!

Step 1: Plan It Out With a Drawing

I've attached some PDF's of very specific dimensions - but, I like to draw things by hand to start. Gives me sense of the test fit. Just keep in mind you're working with a 2x4, so that sets some limits. Measure the 2x4 you're using to make sure of it's actual size (usually a bit smaller than 2" by 4") and go to town on the drawing.

For a simple roblocknic, use the existing width of the board for the body, and cut out a square. So draw that square on the paper. Then, using a ruler, try some different sizes for arms, legs, and head.

You can also buy some smaller stock material such as 1"x4" furring strips or other sizes for arms and legs AND 2"x2" sticks for head. But, to keep this a purist 2x4 only project for the contest, we'll stick with those - that's actually how I make them anyway: All 2x4!

So, you have dimensions now. Maybe a tall head, or really stubby legs. Use your imagination - then mosey over to step two for some wood cutting! yeah!

Step 2: Cut That Wood!

There are many ways to cut a 2x4 into smaller pieces. I'm lucky enough to have a bandsaw. I like this tool because it makes nice straight cuts with less setup time than some other power tools.

If you're just doing one, and you don't have access to a bandsaw or table saw, a handsaw with miter box is great. In fact, when I was prototyping them, this is what I used because it was so easy to just cut up what I needed by hand.

My other tip for cutting wood is to mark on the wood with a pencil (have to erase those marks later). A speed square or some other mark/measure tool for straight(-ish) lines is nice to have. But remember, this is a handmade wooden toy, it doesn't have to be perfectly cut. The handmade imperfections are part of the charm.

So, mark the blocks with the pattern, take your time, and cut out the basics shapes.

Onward to sanding!

Step 3: Sanding, Oh Sanding - My Arch Nemesis

You must sand. As with any wood project, sanding is a critical step. I use plain old sandpaper of successively smother grits to get the finish I want. The amount of sanding completed will directly effect the smoothness of the overall toy. I've done some rough before, but it's hard to deny the prettiness of the paint job on a nicely sanded robot. Makes it shine.

Anyway, find some music, put on a favorite Instructable video series, or just go into a zen state - and sand away.

Don't worry, it'll all be worth it.

Step 4: Drill Baby, Drill

We need some holes for those magnets to go into - therefore, we shall make holes.

A forstner bit with a drill press is ideal. But, make a hole however you must. A hand drill with a regular bit will work. Just use some wood putty to fill in the cone shape at the back of the hole so it is flattish for the magnet.


#1 - Make sure the hole size matches the magnet size. If you use a 1/4" diameter magnet, make sure the drill bit matches. There is always the chance of a slightly larger hole, but that can be filled with epoxy too.

#2 - Mark the center of the holes. This can take a little measuring jujitsu, but the goal is to get each magnet relatively centered and equal to its opposing partner in the case of the arms and legs. A punch for marking the center of the hole is a good way to keep the drill bit on target too (prevents what is known as "walking" - when the drill bit wanders away from where the whole was intended). If you're using a hand drill, be sure to clamp it down good. Same if you're using a drill press of course, but the hand drill really needs that extra support.

#3 - Drill the hole - but not too deep. You want the magnet to be flush with the surface of the wood once the magnet is inserted. This is so the different body parts snap together nicely. Wood putty/filler can be your friend if you over do it. Just make sure it dries before you add the epoxy. If using a drill press, setting the depth stop nut is ideal (if there is one - not all drill presses have them). A good hack for a hand drill is to mark the depth desired on the drill bit itself with a marker, then drill until you can't see the mark (regular drill bit more so than forstner style).

Ok, that was a lot of 'splainin' - in short, make those 10 holes - 5 on the body, one each on the 4 appendages, and one in the head/neck.

Now - let's GLUE!

Step 5: Let the GLUING Begin

Before any gluing can be done, we must first determine the poles on our magnets. I find that a simple black mark on the sides you have designated "North" to be most effective. Now when you epoxy the magnet, you have a sure fire way of knowing the right way to attract arms, legs and head to the body.

Following the directions on the Epoxy, mix enough for one magnet hole at a time. You don't want to mix them all at once and not have enough time to set the magnets in the holes correctly. Any spillage onto the magnet or the wood can be carefully sanded away. Don't sand too aggressively or you will scratch the surface of the magnets.

Step 6: Bringing Roblocknics to Life, Also Painting

Now the fun part begins! Let your artistic tendencies and creative juices flow for this. The blocks can be primed or not, its up to you. I prefer having some of the wood grain showing through the paint. Since the arms, legs and heads can be swapped with each other, coordinating color schemes may be used. I chose to paint the numerous ones I have made a solid color and then picked a matching color scheme for the decorations and robot details.

Step 7: Optional - Making the Robot Bits

This would be a bonus step if you are happy with your painting skills. Final details can be done in paint but I happened to have a silicone mold for hot glue that was very easy to repurpose for this project. I just used polymer clay instead. Since the mold is silicone, as long as the polymer clay wasn't too soft, the pieces came cleanly out of the mold. Once you've made as many gears, buttons, clock faces, and levers as you like, follow the polymer clay's baking instructions. (I find 275 for at least 30 min is a decent starting point)

At this point, you've either used matte paint to give the polymer clay pieces some "tooth" to hold on to, or you may need to sand (rough up) the painted wood. Using the Gorilla Superglue, glue and hold down each individual polymer clay piece to the arms, legs, body, and head. Make sure to leave clearance for the magnets to attract each other, so you don't want to put any raised decorative bits on the magnetic sides of the blocks.

If you don't want to use polymer clay but would like raised detail, washers, nuts, screws, or random electronic parts you have may be used.

Step 8: Seal

Use any Acrylic paint sealer for a nice glossy, indestructible finish. You want to protect your handiwork and make the colors pop!

Step 9: Conclusion: Build Your Robot Army

Now that you've made one robot, got get a truckload of 2x4's and start making your army. You'll also need that steady supply of RARE EARTH MAGNETS, those super not-of-this world except they are nuggets of amazing that make it all possible.

If you enjoyed this Instructable and the Roblocknic ultra-force of wooden awesomeness not to be messed with...

Check me out at my Etsy shop.

Thanks, and Happy Making!!!


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