Introduction: The Official ZeGoBeast Manual - the Crankshaft

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Welcome to the third and final section of the Official ZeGoBeast Instruction Manual!

ZeGoBeasts are mechanical walking creatures which function using Theo Jansen's design for biologically-inspired motion. This manual is the result of a successful ZeGoBeast Kickstarter Campaign in September of 2015, made possible by 63 amazing people from around the world.

The final section will go over how to assemble the Crankshaft, the power-transmitting central axis that moves each of the legs in sequence. This component is what brings together all of the pieces you've built so far to make the completed model.

Make sure to complete the previous two sections (the Leg Assembly and the Core) before moving on to this step.

Step 1: Gather the Parts/Tools

For this final section, you will need the following:

  • Laser-Cut
    • 6x Crankshaft Link
    • 6x Crankshaft Link Cover
    • 2x Outer Link
    • 2x Core Link Cover
    • 8x Bolt Guide
    • 2x Outer Brace
    • 2x Handle
  • Hardware
    • 2x Small Bearings (685-ZZ)
    • 2x 13" Threaded Rod (1/4-20)
    • 24x 1" Hex Bolt (1/4-20)
    • 2x 5/8" Pan Head Bolt (10-32)
    • 2x Nylon-Insert Lock Nut (10-32)
    • 50x Thin Hex Nut (1/4-20)
    • 16x Serrated-Flange Lock Nut (1/4-20)
    • 8x Nylon Washers (.194"x.375"x.032")
    • 4x Cap Nuts (1/4-20)
    • 8x 11mm PVC Tube (1" ID)
  • Tools
    • Hammer
    • 2x 7/16" Wrench
    • A set of Calipers or other measuring tool

Step 2: Attach the Support Rods

Step I:

Slip one of the Threaded Rods through the Core Braces holes on one side of the Core Assembly. Make sure to thread Flanged Nuts on the Rod as you go along, so that you end up with a Flanged Nut on either side of each Core Brace. Repeat for the other side.

Step II:

Measure the distance between the end of the one of the Rods and the face of the Core Brace. Adjust the Nuts until the distance between both ends of the rod are equal, while making sure that there is enough clearance for the Core to spin freely between the Braces. Once satisfied, measure the distance between the Core Braces, and mirror that to the Threaded Rod on the other side of the Core Assembly. Keep this same distance as you adjust the rod on the other side be centered.

Step III:

Make small adjustments so that the Core Assembly isn't skewed at all. If you attached the Spring already, this may be a noticeable problem. Once straightened, use your Wrenches to lock down the position and angle.

Step 3: Attaching the First Link

Step I:

Insert the Hex Nuts into the Crankshaft Link using your Hammer. Make sure that you insert the nuts flush with the surface with the markings on it (otherwise, the Bolts you'll use later on won't be able to reach).

Step II:

Insert the Bolt Guide into one of the PVC Tubes so that it sits flush with the surface.

Step III:

Insert three of the 1" Hex Bolts through the Crankshaft Link, followed by the PVC Tube with Bolt Guide. You may need to turn the Bolts into the Bolt Guide in order for it to go all the way through to the other side.

Step IV:

Place one of the Core Link Covers over the Outer Core Plate.

Step V:

Slide one of the Legs onto one of the Support Rods through the E holes. It doesn't matter which side at this point.

Step VI:

Place the Crankshaft Link Assembly though the larger holes in the Upper and Lower Arms and use one of your 7/16" Wrenches to bolt it to Outer Core Plate below. The arrows on the Crankshaft Link should be pointed towards the center of rotation of the Crankshaft. Keep it a little loose for now - you'll be adjusting it later.

Step 4: Building Out the Crankshaft

Part I:

Use two of the Thin Hex Nuts to lock down the location of the previously attached leg. Leave enough room for the Leg to move freely, then hand-tighten the nuts against each other.

Part II:

Place two more of the Hex Nuts on the opposite side, not locked down yet, just close enough to make it easy to use later.

Part III:

Place a Crankshaft Link Cover over the previous Crankshaft Link.

Part IV:

Attach another Leg the same as previous step (just without the Core Link Cover and with a leg of the opposite orientation). Before each Leg is completely attached, try moving the Crankshaft in a circle to see what the kinematics look like. At its farthest point, the Leg should look like the first attached picture - a little gap between the the A and C Holes. If A and C are touching, then the previous Crankshaft Link is angled too far outward from the center. If A and C are much farther apart (such as with the attached picture) then the previous Crankshaft Link is angled too far inward for center. Again, the arrow markings should be pointed directly towards the center of rotation.

This is probably the single most important part of building a machine that works well. Take your time, be careful, only change one variable at a time, and don't be upset if you have to disassemble the whole crankshaft again to fix a mistake you made earlier on in the setup. I've done it countless of times - it's all just part of how this works. You'll get it, don't worry!

Part V:

Repeat this one more time until you have three legs on the current side of the machine.

Step 5: Capping the Crankshaft

Part I:

Insert one Nylon-Insert Locking Nut into the Outer Link with the entry point of the Locking Nut sticking outward (the side you can't insert a bolt into should sit flush with the surface of the Outer Link). Also insert a Small Bearing into the Outer Brace.

Part II:

Repeat the previous step using the Outer Link instead of the Crankshaft Link. Make sure the entry point of the Locking Nut is facing outward from the machine during this step. Leave this somewhat loose for the next part.

Part III:

Lightly attach the Outer Brace to the Outer Link using a 5/8" Pan Head Bolt. Spin the Crankshaft until the Outer Link seems centered to the Outer Brace bearing, then bolt the Crankshaft down using your wrenches to keep the position.

Part IV:

Put together the Handle Assembly by:

  1. Taking a 5/8" Bolt
  2. Placing a single Nylon Washer on it
  3. Placing the Outer Brace over it
  4. Followed by 3 Nylon Washers, and
  5. The Handle directly over that

Part V:

Place two Flanged Nuts facing outward onto the Support Rods, followed by the Handle Assembly we just made. Attach to the rest of the Crankshaft via the 5/8" Bolt and aligning the holes in the Handle with the Hex Bolts on the Outer Link. Use two more Flanged Nuts to secure the Outer Brace, followed by two Cap Nuts to finish off the Rod.

Part VI:

Repeat for the other side.

Step 6: Congratulations!

You're done! You've officially built your very first ZeGoBeast!

We hope it's been an awesome journey. Remember to take your time with this and relish the art of troubleshooting. The fewer things you can change between test the better, and don't forget to record your findings along the way! They'll help you out later when you're trying to remember why you chose to take a certain course of action.

Please feel free to contact us with any questions you have! Feedback is also welcome - send us an email and we'll definitely take a look.

To our backers, thank you again for making this happen. It's been a blast so far, so hopefully there will be more to come.

Thanks and take care,

- Alex and Dan