Anansi Hexapod Robot

The Anansi Hexapod Robot is a 3D-printable hexapod frame based on 24 Dynamixel MX-28 Robot Actuators. The design is radially symmetrical and offers mounting points for custom electronic components to be added.

License

• Anansi Hexapod Models by Bryce Cronin (http://cronin.cloud) is licensed under a Creative Commons Attribution 4.0 International License.

• Anansi Hexapod Renders © 2020 by Bryce Cronin (http://cronin.cloud) is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Components

Components to 3D-Print

Unless where otherwise noted, it is recommended to 3D-print these components with normal print settings.

Image	Component	Required	Quantity	Notes
	Body_Connector	✔️ Required	6	-
	Body_CoreSpacers	❌ Optional	6	Optional, but recommended to prevent overtightening of the M6 60mm Bolts.
	Body_BoardMount	❌ Optional	4	This component can be added to the Body_Connector component to provide mounting points for electronics, however it is recommended to design a custom component to suit your exact needs.
	Core_PartA	✔️ Required	1	May require high-precision 3D-print settings to allow for the M6 Hex Nuts to be inserted into this component.
	Core_PartB	✔️ Required	1	May require high-precision 3D-print settings to allow for this component to be inserted into Core_PartA.
	Leg_ConnectorA	✔️ Required	24	Print this piece so that it looks like a 'U' shape when looking from above, this will make it flexible so that motors can be inserted and removed. Alternatively, you can edit the model to extend the oval shape to the very edge so that motors can be inserted and removed without a great amount of flexibility in the printed model.
	Leg_ConnectorB	✔️ Required	18	18 are required, but 24 are recommended if aesththetics are important to you. If you use 24, attach the extra components between the Leg_ConnectorB component and the spacers in each foot.
	Leg_BearingMount	✔️ Required	24	-
	Leg_BearingSpacer	✔️ Required	24	Print with high precision - it should fit snuggly into the recess on the Dynamixel motor. If it doesn't fit snuggly, consider designing a custom version of this component with your 3D-printers settings in mind.
	Leg_HornCap	❌ Optional	24	This component is purely for aesthetic reasons. It's optional, but will make your hexapod look nice and symetrical.
	Foot_PartA	✔️ Required	6	-
	Foot_PartB	✔️ Required	6	-

Other Components

You'll need to purchase or fabricate the below components yourself. I've included links to the exact products I used for illustrative purposes only, I recommend finding similar products that are available for purchase in your region. Consider 3D-printing the Core_PartA and Body_Connector components in order to test the sizing of screws and bolts before purchasing.

Component	Required	Quantity	Notes
Dynamixel MX-28 Robot Actuators	✔️ Required	24	These come in a few different models (T, AT, R, AR, etc). https://www.trossenrobotics.com/dynamixel-mx-28-robot-actuator.aspx
8mm x 22mm x 7mm Bearings	✔️ Required	24	https://www.ebay.com.au/itm/282588304295
Rubber Feet	❌ Optional	6	20mm x 20mm so that they fit the bottom of Foot_PartB. https://www.jaycar.com.au/rubber-feet-large-stick-on-pk-20/p/HP0822
M3 6mm Screws	✔️ Required	168	https://www.jaycar.com.au/m3-x-6mm-steel-screws-pk-200/p/HP0401
M3 10mm Screws	✔️ Required	72	https://www.jaycar.com.au/m3-x-10mm-steel-screws-pk-200/p/HP0404
M3 15mm Screws	✔️ Required	24	https://www.jaycar.com.au/m3-x-15mm-steel-screws-pk-200/p/HP0407
M3 Hex Nuts	✔️ Required	72	https://www.jaycar.com.au/m3-steel-nuts-pk-200/p/HP0426
M3 Washers	❌ Optional	192	Highly recommended, but not required. These are used where the 3D-printed components are screwed into the Dyanamixel motors and the servo horns. https://www.jaycar.com.au/3mm-steel-flat-washers-pk-200/p/HP0431
M3 10mm Spacers	✔️ Required	48	These are required for assembling the 6 feet. Alternatively, you could design and 3D-print a custom foot component that doesn't require spacers. Spacers were used so that the feet could be easily extended or shortened using different sized spacers. https://www.jaycar.com.au/m3-x-10mm-tapped-metal-spacers-pk100/p/HP0901
M6 20mm Bolts	✔️ Required	6	https://www.bunnings.com.au/pinnacle-m6-x-20mm-yellow-zinc-hi-tensile-hex-bolt-and-nut-10-pack_p2320083
M6 60mm Bolts	✔️ Required	6	https://www.bunnings.com.au/pinnacle-m6-x-60mm-stainless-steel-hex-head-bolts-and-nuts-6-pack_p0087642
M6 Hex Nuts	✔️ Required	14	I recommend using lock-nuts for 6 (out of the 14) of these to connect the 6 Body_Connector components together. https://www.bunnings.com.au/pinnacle-m6-x-60mm-stainless-steel-hex-head-bolts-and-nuts-6-pack_p0087642
M6 Washers	❌ Optional	18	Recommended, but not required. https://www.bunnings.com.au/zenith-1-4-m6-zinc-plated-machine-washer-46-pack_p2420281
Glue	✔️ Required	1	A small amount of superglue is required for assembling the core.

Assembly Instructions

Refer to images of the completed hexapod for assistance in assembly process.

1. 3D-Print components: 3D-print the required components. You can find advice for 3D-printing individual components in the 'notes' column in the 'Components to 3D-Print' table above.
   
   
2. Assemble the core: Insert 8 M6 Hex Nuts into Core_PartA. Ensure the nuts are properly centred to the holes, then secure the nuts in place using glue. Then, glue Core_PartB into the cutout of Core_PartA.
   
   
3. Assemble the body: Connect the interlocking wings of the 6 Body_Connector pieces so that they form a hexagon. Use 1 M6 20mm bolt, 2 M6 washers, and 1 M6 hex nut to connect each piece together.
   
   
4. Connect the body to the core: Slide M6 60mm bolt through 1 M6 washer, then through a Body_Connector piece, then through a Body_CoreSpacers piece, then screw into the assembled core.
   
   Repeat this for each side of the hexagon. Go slow, do not overtighten.
   
   
5. Prepare bearing assembly: Insert a Leg_BearingSpacing into each Dynamixel motor (on the opposite side of the horn), they should fit snuggly. Then insert a bearing into each Leg_ConnectorA component, they should fit snuggly.
   
   
6. Attach motors: Follow this step for each motor. Ensure the included servo horn is attached firmly to the motor, then slide it into a Leg_ConnectorA piece.
   
   Next, slide an included servo horn screw through a Leg_BearingMount piece, then through Leg_ConnectorA (and the bearing), then through Leg_BearingSpacer (which is attached the the motor), then screw it into the motor.
   
   On the other side of the motor, use the smaller included servo horn screws to screw through Leg_ConnectorA and into the servo horn in each of the 3 holes. If you want, you can then screw a Leg_HornCap on top to make it look pretty.
   
   
7. Leg assembly: Now that each motor is attached to a Leg_ConnectorA piece, connect 6 of them to the 6 Body_Connector pieces using 4 M3 15mm screws and 4 M3 washers each. (This is also where you add the Body_BoardMount pieces if you've chosen to use them.)
   
   Then, connect another Leg_ConnectorA piece (and its attached motor) at a 90 degree angle to the Leg_ConnectorA piece that is now attached to the body. Do this using 4 M3 6mm screws and 4 M3 hex nuts. This step might be difficult if you're using a bulky screwdriver.
   
   Using 4 M3 6mm screws and 4 M3 hex nuts, connect 2 Leg_ConnectorB pieces together - repeat this 6 times. Then, attach each of these to the end of each limb using 4 M3 10mm screws and 4 M3 washers
   
   Add another motor to the end of each limb using 4 M3 10mm screws and 4 M3 washers. Attach a Leg_ConnectorB piece to the Leg_ConnectorA piece at the end of the limb using 4 M3 6mm screws and 4 M3 hex nuts.
   
   Attach the final motor to the end of the limb using 4 M3 10mm screws and 4 M3 washers.
   
   
8. Assemble the feet: Use 8 M3 6mm screws and 4 M3 10mm spacers to attached Foot_PartA to Foot_PartB. Then, add the rubber foot to the bottom of Foot_PartB. Next, use 8 M3 6mm screws and 4 M3 10mm spacers to attach the foot to the end of the limb.
   
   Repeat this step for each foot.
   
   
9. You now have a completed hexapod. If you've had trouble following these instructions, please refer to fully assembled pictures. Errors may be present in these instructions, but it should hopefully be intuitive to figure out the solution.
   
   Feel free to get in touch with me (Bryce Cronin) via LinkedIn if you have any questions.