2. Assembly
First, clone the software repo (instructions under "Get Repo") as some calibration scripts must be used throughout assembly.
Cut the laser cut components according to the material and thickness labeled in their file names and print the 3D-printed parts.
Create the power and communication cables according to the diagram. The 5V supply can run off of a computer's USB port (simpler) or external supply (recommended).
Two of the longer 3P-XL cables must be spliced together to make a longer cable. They should be soldered in the orientation shown to ensure a good connection and heat shrink the joint to secure it.
Note: some of the hardware/components used have been tweaked since the images for this guide were taken.
Install connectors on the motors.
Repeat for 3 motors.
Collect the motor parts, including 8x 8mm M2 bolts and 4x 5mm M2 bolts, 4x M2 nuts and a shorter string (150mm).
Connect the motor to the computer (one motor at a time) and start the motor calibration script in the top level blossom directory: python motor_calib.py. The motor position will be set to 100 once the script is started and guiding prompts will be printed.
Begin an overhand knot at one end of the string. Insert the 5mm M2 screw into the outer wheel piece and loop the string over the thread and tighten with the nut.
Stack the wheel pieces (outer-inner-outer) and fasten to the servo horn with the 8mm M2 bolts, taking into account the orientation of the string channel in the inner piece (should be facing "down," towards the mounting face of the motor). The motor horn holes are not true M2 threads, you have to dig the screws in while screwing.
Press Enter in the calibration script to set the motor position to 0 and make the next steps easier.
Mark the string 10cm away from the outer edge of the wheel and tie an overhand knot.
Tie another overhand knot after the first knot.
The length of the string when completely taut from the edge of the wheel to the tip of the loop should be 13cm.
Mark 13cm on the string and bend the string back at this point.
Tie another overhand knot between the previous two knots to secure the length of the loop.
Superglue the knot to further strengthen the loop.
In the calibration script, press Enter again to continue; the motor position will be reset to 100 (default position).
At this point, the calibration script will prompt you for a new ID number for the motor. Enter a number from 1-3 and press 'Enter' to set the new motor ID. Repeat for the 3 tower motors so that each are numbered from 1-3.
Run the calibration script for the tower motor and skip to the step to change the motor ID number. At this point, give it the ID 4.
Collect the pieces for the ear motor, including the longer string (300mm).
Similar to the tower motor, tie an overhand knot around the bolt through the outer wheel piece, but make the knot in the middle of the string instead. Fasten with a nut and guide both ends through the open channel in the inner wheel.
Start the ear calibration script and follow the prompts like the tower motor calibration script, giving the ear motor an ID of 5.
When the script moves the motor to position 100, fasten the wheel (outer-inner-outer) to the horn, with the inner string channel again pointing downwards.
Press 'Enter' in the script again to move the motor to position 150, which it where it must be for assembling the ears.
Some components need to be glued as shown, pay attention to the orientation of the parts, taking into account the relative hole sizes as described. The larger holes are to countersink the hardware.
Base Bottom
The piece with larger holes (right) should end up on the bottom.
Base Top
The piece with larger holes (left) should end up on top.
Base gear
The piece with larger holes (right) should end up on the bottom.
Base motor holder
The piece with the larger holes should end up on the top.
Tower
Tower gear
The piece with larger holes (left) should end up on the bottom.
Ear stands
Make sure that the left and right pieces are mirrored from each other.
Collect the base components.
Note: the block on the bottom plate present in the pictures is no longer included in the current design.
Collect 3 of these Phillips screws and nuts.
Assemble the top portion of the base by lining up the base motor holder and top plate (Phillips 2.0).
- Make sure that the counterbored side of the top plate (with larger holes) is facing away from the motor holder.
Insert the screws to fasten the motor holder and top plate.
Screw the base motor gear to small holes in the base motor.
Collect the standoffs and their screws.
Install the standoffs to the top plate.
Attach the bottom plate.
Collect the tower support components.
Collect the 3 standoff screws for the gear clip.
Assemble the gear clip.
Assemble the tower support.
- Ensure that the discs are the same size (there is a similarly-shaped part that is a smaller diameter).
Screw the tower support to the gear clip (Phillips 2.0).
Assemble the tower.
Wrap (3) rubber bands along the tower to keep it pressed together.
Completed tower.
Attach the base to the tower, threading a long 3P-XL cable from the base through the center of the tower.
Collect the motor mount pieces. Take note of the ID numbers (labeled on the back of the Dynamixel motors) and use the corresponding motor mount pieces.
Ensure that the longest snap fit peg is facing the direction of the motor wheel.
Connect the motors using the shorter 3P-XL cables in the order shown.
Connect the cable from the base to motor 1.
Snap the motor assemblies into the tower, in ascending counter-clockwise order (1 -> 2 -> 3).
- This may be difficult to get it completely aligned and snapped in; it may help to remove the tower from the base first.
- Make sure that the strings are not pinched by any of the components when putting them together.
Connect the USB cable to the base motor.
The motors must be set to their default position before the tower is installed.
Connect the power and USB2AX cables to your computer.
Start the command script:
python start.py -n woody
Type s -> Enter -> reset to reset the motors.
Loop the motor string through the guides in the tower legs.
Collect all the head components.
Assemble the ear stands and connect them to the platform along with the motor.
Attach the ear hinges to the ear stands and pass the strings from the ear motor through the guides as shown. The strings should wrap around the wheel clockwise, with the string to the left ear passing over the wheel.
Wrap the string around the bolt through the ear hinge and fasten it by tightening the bolt. Make sure that the motor wheel does not rotate and calibrate it such that the bolt is almost flush against the ear stand as in the second photo.
Attach the head shapes to the platform.
If adding a cover, pass it over the tower now before attaching the head.
Attach the head to the tower.
- The front of the head should be facing in the direction of motor 1
- Double-loop rubber bands from the tower's "hook" attachment points.
- Loop the other ends of the rubber bands to the attachment points on the head.
- Loop the string ends on the attachment points.
Connect the double-length 3P-XL cable from the ear motor to the vacant port on tower motor 3.
