Class 02: Motor hub and bracket

Motor hub and bracket homeworks #

Create a secure motor attachment

Later this semester, Projects 2 and 4 will require using a motor to actuate some part of an interactive game, and Projects 5 and 6 will involve motor-driven wheels. So in these homework assignments (also known as “Project 0”), you’ll be building some knowledge about how to attach a part securely to a motor.

Motor hub #

Your first task is to design and build a motor hub that meets the following requirements:

It fits on and attaches to your DC motor shaft
It stays attached securely enough to handle the amount of torque (load applied to hub) that stalls the motor when it is operating at 12 V
It can be removed
It includes a 3 mm hole located 15 mm from the central axis of your DC motor shaft (you’ll insert a paper clip with a weighted string into this hole)
Around its circumference, it includes a channel or groove for winding up 1 meter of string

Your motor hub can be shaped however you like as long as it meets these requirements; the details are up to you.

Procedure for motor hub testing:

Attach your motor hub to your motor. Hold your motor securely in one hand or in a clamp. Power the motor at 12 V. Test to see if you can make the motor stall (stop spinning) by grasping your motor hub with your other hand (or a tool). If the hub slips around the motor shaft and allows the motor shaft to keep spinning, your hub does not pass the stall test.

Submit to Canvas (1) a photo of your motor hub and (2) a brief video (max 30 seconds) demonstrating that your motor hub meets the requirements above, including the stall test.

Click for info on preparing to use the Bray Shop 3D printers, laser cutter, or lathe ...

All students must complete the Bray safety quiz prior to their first visit to Bray. Completing the quiz will give you access to the Bray user site where you can submit appointment requests for training and fabrication time.

Use of the Bray lathe requires lathe-specific training in the red zone, which must be booked by appointment.

ME and HFE students can use the Bray 3D printers and Bray design studio anytime using their Bray building access, which is 8am-midnight every day.

Students can book an appointment to use the laser cutter or just walk in to use it during shop open hours as long as it is not reserved or in use by someone else.

Click for info on preparing to use the Nolop 3D printers or laser cutter ...

For more information about the Nolop 3D printers, review the training guide here.

Tutorials on using the Nolop laser cutter are available on the Nolop website here.

Prior Student Examples NOTE: Not all of these examples meet the requirement of a channel or groove for the string to travel - that was new in 2025!

motor hub collage

Motor bracket #

Your second task is to create a bracket that holds the motor housing in place by meeting the following requirements

It prevents the motor housing from rotating with respect to a flat horizontal surface (like a piece of scrap wood, standing in for a future game platform or robot chassis)
It accommodates your motor hub (your hub can still be attached and removed from the motor shaft)
It can be attached and removed from a horizontal surface (the piece of scrap wood) without removing the motor from itself (so don’t put mounting bolts underneath the motor where you can’t get to them)