Rear Motor Mount Clamp Design Report

Owned by Andrew Wright
2023-04-03
3 min read

Requirements:

  • Motor mount must be easily removable

  • Motor mount must not move during flight

 

Current Motor Mount:

The current rear motor mounts were custom caded to fit the unique dimensions of each side of the ICARUS frame. The motor mount comes in two parts, the top and bottom. The top of the rear motor mount has been water jet and machined out of a 3mm aluminum sheet and rests at a 3 degree angle on the bottom of the motor mount, which is 3D-printed out of carbon fiber filament. A picture of the physical prototype is included below.

Problem Definition:

When testing the motor mount prototypes, it was noticed that the motor mounts could slide horizontally down the ICARUS frame given enough pressure. This is a major problem due to the propellers and motors needing to be securely fixed in place to ensure the drones in-flight success.

 

Solutions:

When ideating potential design solutions which modified the pre-existing mount to solve the movement issue, I settled on three different designs to explore.

 

Solution 1: Clamp Bottom of 3D Printed Mount

  • This solution consists of a M3 bolt which fastens both sides of the bottom of the 3D-printed mount to prevent movement via friction.

Pro’s:  

  • Relatively easy CAD modification

  • Is likely to work based on previous shaft collars/clamps performances

Con’s: 

  • Need to buy new flathead screws due to the motor mounts elongation 🙁

Sketch:

3D Printed Bottom of Mount CAD:

 

 

Solution 2: Clamp Top of 3D Printed Mount

  • This solution consists of a M3 bolt which fastens both sides of the top of the 3D-printed mount to prevent movement via friction. This solution is less likely to be as effective as the previous clamping method due to the 3D-printed material not having much leeway to bend due to its close proximity to the aluminum top mount. 

Pro’s: 

  • Very easy cad modification

Con’s: 

  • Raises entire motor, meaning the front motors will have to also be raised and reprinted

  • Is less likely to be effective in clamping capabilities due to close proximity to the aluminum motor mount top

  • Need to buy new flathead screws due to the motor mounts elongation 🙁

Sketch: 

 

Solution 3: Vertically Clamp Via Wedge

  • The original design of the motor mount was intended to be fixed in place due to friction caused by pressure between the flat aluminum top motor mount and the ICARUS frame. This however could no longer be achieved due to the motor mount needing to be shifted 3 degrees, as the aluminum motor mount top could no longer effectively press into the ICARUS frame. To solve this, a wedge with a pitch of 3 degrees could be placed under the aluminum motor mount top to allow a successful clamping between the top and bottom pieces. 

Pro’s: 

  • Easy CAD modification 

  • Does not require extra screws

  • Can still use current flathead screws

Con’s

  • Is unique method of clamping so would require extensive testing

CAD:

*The aluminum top of the motor mount has proper holes in real life.