Introduction: Clock'r Walk'r: the Clock Powered Theo Jansen Strandbeest
I began this project by stumbling upon this Thingiverse project which caught my attention. I had known before about the so called Strandeests but I had no clue about how it functioned. After checking the model out I quickly drew up a SolidWorks assembly model to see if the sketch I found was correct because it seemed too simple. When I saw it worked (at least in the assembly) I started to model the real thing to be made.
Tools I used:
USB Soldering iron (you can use a normal soldering iron or alternatively a lighter)
Liquid and Gel super glue (not a tool though)
Toothpicks (also not really a tool but they're helpful for spreading the super glue)
M3 screws (I used 16mm ones but at least 10mm is required) x16
3D printed parts
Step 1: The Actual Design
I began the designing process by first modeling the basic shapes of the individual parts to get the arm lengths and joint distances (the geometry) to be just right. When I was happy with how the assembly "walked" I began to model real parts that would be assembleable. After refining the design a couple of times because I was not happy with how it looked I had the first version ready to be printed.
After printing I (of course) realized some of my mistakes and designed the version 1.1 which was good to start assembling. Through the assembly process I realized I was missing some parts such as the distancers an stubs.
After adding all the skipped parts to the models folder I printed them all and when I was happy with how it looked (version 1.4) I went on to the assembly.
You can download all the parts for this model on my Thingiverse page and I will also include the files here.
Step 2: Printing the Parts
I printed all the parts I designed on my Anet A8 3D printer using a 1.5mm layer height with 10% infill. I used PLA filament because that is the only filament I like to use. After printing and gathering all the parts You should have 56 pieces altogether (plus the screws and nuts).
Step 3: The First Step
The next couple of steps will be a sort of a step-by-step guide to assemble the contraption.
To begin assembling the Walk'r you first need to assemble the case and the "drive axle". Begin by sliding the eccentric axle through one of the two holes in the case. As You are sliding it through ad the Gear on to the end of triangular part of the axle and put the axle cap on at the other end (as shown in the pictures).
Note: the two eccentric pins on the end must be on opposite sides to one another in order for the robot to walk properly.
When assembled use some super glue to fix the parts in place. The gear and the axle cap must be firmly attached to the axle, be careful not to glue any of the parts to the case as it is a moving part. I used liquid super glue for this step and smeared it around by moving the part on the axle a bit.
Note: the parts must be glued to the axle as straight as possible to prevent grinding on the case.
Step 4: Adding One Leg (up to the "knee")
From now on it gets a bit fiddly.
Begin assembling the legs of the walker by adding the left leg first, no matter from which side (port or starboard) add the first piece to the left pin. The first part you need to add on to the case is the short arm with two holes, place it on the exterior pin of the case and put one of the feet on the pin over it (as shown in the photo). The next piece to go on is the long arm, (note that there are left and right arms) slide the hole on one side of the arm onto the pin on the axle and the other side of the arm, with the pin, into the hole on the foot.
Note: the parts must be free moving so if your parts aren't sliding onto the pins easily (or spinning) You can file down the pins so they are a bit smaller.
Close the leg by adding another foot from the inside of the case (as shown in the photo). At this point You can use a clothes pin or two to hold the leg closed as you pull the screws through. Next, add the two tall distancers between the two feet where the two center holes are and push the screws through.
You can add the nuts on the other side of the screws to keep them from falling out but don't tighten them just yet.
If it is sort of holding together, You're doing good so far. If not, take a closer look at the pictures.
Step 5: Adding One Leg (below the "knee")
To add the part "below the knee" You will need the short arm2 alongside two feet, short distancers and a stub.
To begin, take the short arm piece and place the side with the longer pins in between the two feet of the upper part of the leg. You can now tighten the screws that You left untightened before, the tension that you can get with just your fingers should be enough to hold but you can use a screwdriver and pliers if you want.
Lay the walker to it's side (as in picture 4) and add one foot under the short arm so the pin of the arm sits into the foot. You can also add the stub in and the screws from the bottom, onto the screws add the short distancers and then close the leg with the other foot. Tighten the screws on the bottom part of the leg.
Note: if the arms can't move freely when you tighten the screws it might be because your distancers didn't print properly and are too short, you can fix this by adding a washer or printing new distancers that are slightly taller.
The bottom part of the leg is now dangling on only one arm but we will address that in the next step.
Step 6: Adding the Second Leg
Adding the second leg is essentially the same as the first but mirrored to the right. The layout of the arms is slightly different though so look at the photos closely.
Adding the first short arm and the foot is the same as on the left side. When You are adding the long arm pay attention to the grooves cut into the side where the hole is (remember that there is a left and a right) they need to sit into one another as shown in the photos 1 and 2. Close the leg by adding the second foot from the inside of the case and use distancers and screws to hold it together.
Adding the part "below the knee" is the same as on the first leg but mirrored.
If the legs look a bit dangly at this point, don't worry it will (mostly) get fixed when it is fully assembled.
Step 7: Connecting the Legs to the Axle
If You followed the prior steps correctly, You should have something that looks a little bit like the photo 1.
To connect the legs to the axle and make them walk You need the parts longer arm and longer arm2 (they are a left and a right just like the long arms). First slide the arms onto the pin on the axle like in the photo 3 so that their grooves line up just like the long arms before.
Once the longer arms are in place, connect them to the legs by sliding the short arm in between the two feet of the bottom part of the leg and pushing the pin on the longer arm through to hold them (as shown in photos 4 and 5). Do the same for the other leg and it should look something like photo 6.
Step 8: Fixing Things in Place
As You probably noticed if You tried to spin the gear, the arms are falling out as is. This is why we need to fix them on the axle to stop them doing so.
Push the arms on the center axle all the way to the wheel and You can see that the pin is longer then it needs to be. I used a soldering iron to melt and expand the end of the pin so the arms can't fall off. If You don't want to damage your soldering iron (or You don't have one) you can use a lighter to slightly warm up the pin and then push it in with your finger. Alternatively, you can glue up a small washer or something to the end of the pin.
Note: be careful not to melt (or glue) the pin too much because the arms need to be free spinning on the pin, we just need to stop them from falling off.
If the other end of the longer arms (the side with the pins) is falling out of the leg, You can use the same method as with the pin on the axle.
Step 9: Adding the Other Side
Just refollow the steps 4 through 8 but on the other side of the case.
Note: building the thing gets trickier the more You put on.
Once done, You should have something that looks like this.
Step 10: Adding Propulsion
Once You have the walker assembled it looks cool but it's only that, cool. Now we need to add something to make it move.
For this step You need a wall clock mechanism and the worm gear piece. You will also need two nuts for the wall mechanism in order to attach it to the case properly but most mechanisms like this come with just the one so You have to find a second one somewhere. I salvaged mine from another clock mechanism I had.
First up, put one nut onto the mechanism threading and push it through the hole in the case from underneath. I had to make sure that it goes through the hole as little as possible in order for it not to interfere with the gear but depending on your mechanism it might not be necessary. Once lined up tighten the nuts on the mechanism to fix it in place in the case.
Note: make sure You put the mechanism in so that the battery compartment side is under the gear, for better weight distribution.
When the mechanism is fixed in place test fit the worm gear and if You are happy with the placement glue it on to the minute hand (the center pin) of the clock mechanism. I used gel super glue for the worm gear as it showed to be more precise.
Step 11: Adding the Second (time) Hand
At this point the walker is complete and it will walk propelled by the gear attached to the minute hand on the clock mechanism. I decided to ad a second hand to the mechanism as an indicator that the mechanism is moving and also if the battery is okay. To add this, I left a hole in the worm gear through which a second hand axle can be attached.
To begin I took the second hand and cut of the small tip on it that connects to the mechanism (photo 2). I then sanded down the end of it to be flat so it would be easier to glue to the toothpick. I glued one end of the toothpick to the second hand tip using gel super glue and when it was completely dried I plugged it into the mechanism. Next I cut the toothpick to length and trimmed down the second hand so it doesn't hit the legs of the walker.
Note: make sure that the second hand doesn't hit any parts of the walker because if it does it will stop the clock mechanism and the walker from walking.
Step 12: Wait... a Long Time
Now that it is complete plop a double A battery in the mechanism and it will... walk! If you see the second hand ticking (or spinning, depends on the type of mechanism used) that means that it's working as it should. All that you need now is patience.
The walker is slow but that was the main idea I had, a sort of a time piece that would eventually fall of the shelf that it's on. The worm gear reduction to the axle is 30:1 and because it is connected to the minute hand this means that every thirty hours the main axle on the walker makes one revolution and the walker makes one step forward. One step correlates to around 2 or 3 centimeters so it would take somewhere in the neighborhood of a week for it to move by a noticeable distance. Even when it isn't moving it still looks kinda cool.
I will try to set up a long time (a week or two) time lapse recording of the walker and update this instructable with the video.
Runner Up in the
Make it Move Contest 2020