2023-01-31 - Switch push motor from 300KV to 230KV for greater efficiency

Requested by Nathan Green - Luigiman54#2439

Description of Change

The current rear push motor is the T-Motor AT4130 300KV. We purchased this high KV motor because we initially thought the largest peoipeller size that would clear the lift props was 16 inches. This motor is rated for a 14 or 15 inch prop, and we elected to use a 15x8 APC propeller. We have now realized that since the motor is an outrunner (the entire motor bell spins, not just the shaft) that the motor has to be mounted on the shaft end (the top) instead of the bottom. This mounting setup allows the push propeller to be a few inches closer to the front of the plane, hence a larger propeller can be used. We would purchase a 230KV AT4130 motor and use an APC 17x10 prop.

Implementation

The new motor will be a drop-in replacement for the current one.

Reason for Change

The efficiency of propulsion will be increased. For example, the efficiency will increase by ~15% at 2kg of thrust, ~22% at 5kg, and ~30% near max throttle. The full chart can be seen here https://store.tmotor.com/goods.php?id=828

Priority

Medium

Impact of Not Responding to Change

Icarus will draw 15-30% more current to fly in plane mode.

What Groups, People, Sub-teams Need to be Notified?

• Mechanical

Change Impact

Additional Parts/Resources Required and Costs

1x T-Motor AT4130 230KV

2x APC 17x10E Props

Total cost: $190

Impact on deadlines

Once parts arrive: 10 minutes

Alternatives and Recommendations

Alternative is to fly on the current motor with less efficiency.

Comments

Change Request Sign Off <System Integration>

Status

Accepted / On Hold / Rejected / More info Requested

Comments

Signatures/Name