Heard of a rag doll? Those often-homemade dolls built from scraps of fabric? Source of Raggedy Ann? I sometimes work with fabric, but lately I've been doing a lot with wood, and decided it was time to make a wooden toy from those scraps of wood I've been hoarding. It was also a good opportunity to play with the toys that Crashspace acquired for the Dremel/Instructable July Build Night.
I already have a Craftsman rotary tool, which usually does the job for me, but for this project I got to play with the Dremel 4000 and the Multi-Max, and a couple new attachments. I also already had a Dremel Multi-Vise, which has attachments both for mounting a Dremel and for a general clamp. It's been a huge help in keeping all my fingers intact; I figure God put em that way for a reason. That said, you will probably see scars and band aids and such in these pictures, cause God also made me a klutz.
I'm a massive tinkerer, so you will not find instructions for making these specific shapes, nor exact measurements. Most of what I'll detail here is the way that I created the articulated joints and assembled it all. Take it as suggestion, try variations, and let me know about your experiments. Snag some materials and see what kind of shape you come up out of what you have available. Play around with them. I tried different configurations before I settled on this one.
Step 1: Gather Stuff
Look for scraps anywhere. In addition to fun shapes and blocks, you'll want dowels, bamboo skewers, etc. It doesn't have to be all wood, though if you plan to use another material, you might need different attachments, tools, or adhesives. Check out this blog post about Jill Timm's Dremel workshop, and thistothat.com for how to adhere different materials.
Next, sort. Push things around, figure out what you want to make, whether bot or animal or jazz-powered submarine or whatever. You can change your mind later, it's your project after all.
Step 2: Articulation - Arms, Neck
My bot's torso is made of two squares with holes that were leftover from another project. The arms, neck, and abdomen are all attached to the torso by way of holes and pegs for each piece. Peg holes went into both sides of the torso. I drilled a hole (slightly larger than the size of the peg) into the end of the arms and neck, and slipped them onto the pegs, creating simple joints that spin easily on their fulcrums. You can make the holes a little smaller if you want your joints to have more friction, but I wanted floppy limbs.
Drilling holes into dowels is delicate work, so go slow. Note which direction your tool is likely to slip, and then make sure to put your fingers not there. They can be anywhere else, really. Just plan ahead for fumbling and your hands are more likely to remain unscathed.
I sanded the end of each dowel down around where I'd made the hole so that there would be plenty of room for them to rotate and not bump into each other. Perhaps try sanding or cutting down parts of the dowels to give them a little more shape.
Step 3: Articulation - Abdomen
The abdomen is more complicated. I could have used a dowel the way I did with the arms and neck and drill a dowel-sized hole to wedge it in the abdomen piece, but I wanted it to be more connected to the torso, so I instead cut a block of wood down to a similar depth as the dowels, drilled a peg hole, and dropped it on the peg. As with the knees, you'll want to sand curves into the abdomen piece to give it freedom of movement. Check out the pictures to get an idea of how it's shaped.
The bottom of the abdomen has a hole drilled sideways for the hip dowel, which extends and gives the legs somewhere to attach. I accidentally drilled a hole the wrong way, which - after thinking about how much time I'd already spent on that piece - I decided added "character," and should totally stay the way it was. Feel free to make your rag bot look like swiss cheese if you like.
Step 4: Articulation - Hip
To give another plane of motion to the legs, I attached them to the abdomen by way of a dowel that goes through that hole I just mentioned. There are plenty of ways you could hold the hip dowel in place (such as pegs that run through the outside ends of the dowel), but I decided on maybe the most complicated way, because it's more subtle, and because it uses a rubber band. Rubber bands are nearly always fun, unless you snap them into your eye. Do not snap them into your eye.
In this method, you have to drill a hole longways through the dowel. It's tricky. Use a smallish bit, and go slow. To tell if you're going straight, periodically let the dowel spin on the drill bit. If it doesn't wobble (much), you're in good shape. Once I had my hole, I used a cutting wheel to carve a little slot in the center of either end. In this slot went a narrowed piece of skewer (thinned down using an X-Acto knife) just a bit longer than the diameter of the dowel. I happened to have some small, thin hair bands, which work well. The rubber band runs through the center of the dowel and loops around one of those skewer pieces at each end. See photos to see how I assembled it.
Step 5: Articulation - Knees
I wanted my bot to have knees that bent, so I decided to make them work a bit like a butt hinge. I cut a couple longer pieces of wood in two so that the knees would be sure to match. A cutting wheel on the Dremel works well for this, or you can use a saw if you prefer taking a long time. I lined up the two sections and sketched the knuckles (the interlocking bits containing the axis pin) to be cut. It's a simple joint, so I stuck with three knuckles. Cutting out those small pieces is finicky work, and having some part of it immobilized (such as with a vise or clamp) will make life so much easier. I used a cutting wheel for the basic cuts, and this carving bit to clear out the recessed portions. You'll want to use a sanding bit to round off the edges of these knuckles so that they can rotate cleanly, but FIRST, make sure to drill a hole for the axis. It's a massive pain to try to do it afterward. Pop a thin dowel/skewer/bolt through all three knuckles and check to make sure the joint moves the way you want it to. You might need to do additional adjustments with your Dremel.
To attach the legs to the rest of the body, I drilled a hole so that they could slip onto the hip dowel. Since I wanted to have my knees bend sideways instead of backward and rattle along with the arms and head, I drilled the hole from the front side of the leg to the back.
For more fun with the legs, shape them with the Dremel. That holds true for everything in this project, really.
Step 6: Other Fun - Magnetic Hand!
I happened to have a small magnet puttering around my shop, so I decided to give my rag bot a magnetic hand. I traced the magnet's size onto the end of the hand, and used that same carving bit from the last step to carve out a little pocket for the magnet to sit in. A little piece of plywood the size of the hand glued on top of this, and tada! A hidden magnet hand. The Dremel Multi-Max came out in other parts of this project, when I wanted to get a nice flat sanded surface, and it was especially helpful here, cleaning up those edges of the plywood cap that poked out.
Step 7: Staining and Such
I wanted my rag bot to have a little more variety in its coloring, so after (after!) I'd put all of the pieces together and was happy with it all (AFTER. Don't do this before you know you're done with all the carving. check next step for more assistance assembling now if you need it), I pulled it all apart, sanded all the pieces with fine sandpaper, and did some staining with different colors. Actually, the colors looked a little too nice, so I very lightly sanded them once they'd dried to give them a little more character. Most of them were stained with official wood stain, but for the dowels and pegs I wanted to just be a little "dirtied up," which I accomplished by soaking them for a few minutes in a cup of tea and letting them dry. (There are many tutorials about how to do nice stains with tea, but I only wanted a very subtle change for these pieces, which is all soaking will give you.)
Step 8: Final Assembly
You should have a little experience putting the parts together while building them. I'll just point out a couple finishing touches.
I kept my gluing to a minimum on this project, but there is some involved. I like Titebond for wood. I glued the pegs into one side of the torso (and left the other side unglued so I could pop it open if needed), and then I used a couple spare wooden gear pieces and put together another rubber band assembly like the hip attachment (but minus the dowel) as an extra support for keeping the torso together.
The knees are held together with a skewer in the joint. To hold this in place, I cut the skewer down to fit, carved four little wooden caps and glued them over the openings. (See pictures)
I simply glued on the eyes. If someone decides to try putting LEDs in their bot's eyes, let me know. I decided to forgo it on this one, but I'm mightily curious.
Step 9: Play!
All done! I like how my rag bot rattles when I shake it, which is part of the reason I made it so floppy to begin with. I'm excited to see what other people come up with, given the different materials they have available. Be sure to post pictures if you make a wooden rag bot!