H.S. robotics project

This is not a proposal, but a way to communicate just one fevered vision.


It seems a fair assumption that the Robotics Club members are interested in doing some robotics. But maybe they heard “Nope, we’re not doing robotics, not until FIRST in January. The rest of the year it’s just fundraising (collecting old shoes, selling candy bars) and leaning on parents to be mentors.”

Maybe there’s a robotics project that would help with fundraising. That would combine two problems into one solution.

What if our fundraisers were accompanied by a cute mascot-like robot while soliciting at football and basketball games (and maybe elsewhere)?

I’m thinking of the old organ grinders who had a monkey, maybe dressed like a little person. The monkey was entertaining in itself, and accepted money from passersby and scampered back to put it in the bucket.

The donor/audience experience

The robot is maybe four feet tall, vaguely humanoid. Instead of walking, it rolls. Its two arms can move, its head can nod up and down, and its face has slightly expressive features. Depending on available artistry, it might wear a Viking helmet, or maybe a deliberately cheesy 1950’s boxy look (or both).


When you approach it, it ducks its head, makes sad puppy-dog eyes, and holds out its hand for a donation.

When you put some money into its hand, it lights up and smiles in delight. It drops the money into its money pouch, which the other hand is holding open.

What’s really happening

Automation is hard enough. True autonomy is way beyond the scope. To keep this one simple enough to actually finish, it works by remote control. It’s actually a student who directs it to extend its arm, move its eyebrows, etc. Wireless would be nice, Bluetooth or WiFi from a phone or tablet. Or maybe someone holds a control panel with a cable to the bot.

The hand does not need to grasp (even claws are hard to do). Mechanically, it’s little more than a hand-size cup or bowl. It is kept horizontal by the arm mechanism until it’s tipped into the money bag. [What about bills blowing out on a breezy football day?]

How it is built

At the bottom there’s a platform with the wheels and wheel motors. Wheels for a football stadium need to be bigger than wheels for basketball parquet. Above that there’s a torso, mostly space-taker-upper.

The shoulders bear the arm attachments.

The right arm is the one that reaches out to accept donations. Its upper arm is a parallelogram arrangement, to keep the forearm level. A motor in the shoulder sends the hand out and draws it back.

Just above the elbow, another motor rotates the right forearm — one position is toward the donor; the other position is against its “waist”, just over the money bag.

In the right wrist is another motor. In one position it keeps the “hand” horizontal; in the other it tilts the hand toward the body to dump the money into the money bag.

The left arm is simpler. Its only job is to open the money bag. The near side of the bag is attached to the torso; the far side is attached to the left hand. The left arm moves so that the hand pulls the far side of the bag away from the body, making a space for the right hand to dump the loot.

The head can tilt (nod) up and down. We might simplify this away, but in my imagination it would add to the sad-eyes/joy transformation.

The face has movable eyebrows and movable mouth. The eyebrows change between between sad and happy by simply pivoting. Similarly the mouth can be deformed between sad frown and happy smile.

Static painted eyes might be good enough to convey the emotional affect.

Tiny R/C servos work the facial features. High-torque hobby servos might be adequate to move the arms. [Potential issue: making it robust against “attacks” by aggressive hand-shakers and low-fivers.] Not sure about wheel motors—depends on whether it’s all cardboard or plywood.

Systems modularity

Exhausting as this list might seem, it isn’t exhaustive.

Specialist subteams can work on many of these aspects at the same time, for later integration.  In some cases we might want extra controllers—working on eyebrows shouldn’t contend with arm sequencing, for instance.


– wheel base, wheels, and motors
– battery mounting
– torso and skinning
– shoulder mounts to torso
– neck mount to head
– arm and neck servo mounting
– face servo mounting
– electronics mounting

Articulation/joint attachment

– R upper arm
– R lower arm
– R hand
– L arm
– neck/head


– right shoulder
– right elbow
– right hand
– left shoulder
– head nod
– eyebrows
– mouth

Artistic design

– entertaining for donors/audience
– worthy project for roboticists
– grand vision—cheesy/boxy or what
– overall shape
– overall color scheme
– skinning, surface materials
– shaping torso
– shaping arms and hands
– shaping head
– designing face; eyebrows, eyes, nose, mouth. Dimples? helmet?

Facial expression

– servo attachment(s) for eyebrows
– servo attachment(s) for mouth
– calibrating degree of motion


– batteries
– charger
– separate power for electronics and motors/servos
– perhaps lower wheel motors separate from upper servos
– Raspberry Pi, Arduino, whatever
– wheel motor controller
– servo controller
– control wiring
– power wiring
– cable routing and strain relief


– wheel motor control—left/right speed
– arm/hand/head positioning
– facial feature positioning
– individual controls, used during engineering/development
– pre-programmed cycles, several controls concurrently
— reach out arm then stop
— retract arm then stop
— retract and deposit money, then stop
— become sad
— become happy
— return expression to neutral
– communications (BT, WiFi)
– control panel app (or web page) on phone/tablet
– Raspberry Pi can serve web page(s) to phone/tablet


Materials: Structural stuff can probably be scrounged.  I can donate servos and controllers, and lend up to three RPis (donating one).  That leaves wheels, wheel motors, batteries, and relevant hardware brackets, fasteners, etc.

Time: I can do two 90-120 minute sessions per week.  I haven’t worked with high schoolers since I was one, so my judgment is suspect, but I’m optimistic.  If simplifications are are needed, let’s make them early, rather than drop stuff later after time has already been spent on it.



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