Clamping Leg Blocks
- Conall Kingshott
- Jonathan Di Giorgio
- Alison Thompson
Big Project | Project | Project Manager |
|---|---|---|
2024 Comp Drone | Clamping Leg Blocks | @Conall Kingshott |
Task Description
We are looking to modify the existing leg blocks on the frame to apply a vertical clamping force to mitigate vibrations.
Constraints
Constraints | Written By | Append Date |
|---|---|---|
Apply vertical clamping force to the legs to mitigate vibrations and deformation of materials over time. | @Conall Kingshott | 2023/10/06 |
Minimize weight wherever possible. | @Conall Kingshott | 2023/10/06 |
Incorporate the mounting blocks with side shroud clipping design. | @Conall Kingshott | 2023/10/06 |
Assignees
Assignee | Asana Task | Date |
|---|---|---|
@Jonathan Di Giorgio | 2023/09/21 |
Task Progression/Updates
Author: @Conall Kingshott Date: 2023/10/06
INITIAL IDEAS:
Main body of the block will be made with CF PETG due to its strong strength and resistance to deformation along with the low weight of printed parts.
A slotted will exist in the middle of the part for the clamping end piece.
This end piece will be driven downwards by an M5 screw which will pass through a tapped hole in an aluminum plate at the top of the block.
Printed areas to accommodate the clips for the CF side panels will be added to the print.
Author: @Jonathan Di Giorgio Date: 2024/01/07
V1 of clamps:
The entire assembly was made in CAD, designed to be manufactured by 3D printing and laser jetting of 1/8 inch aluminum sheets
Heat set inserts were used for structural fastening
Includes slots for battery shroud to slip into with help from @Andy Zhang
New holes were drilled into the drone chassis to accommodate the new fastening layout
The assembly was manufactured and installed onto the drone
The installed clamp was visibly successful at reducing vertical vibration and flexure
Author: @Jonathan Di Giorgio Date: 2024/01/07
Failure of clamp V1:
After some time on the drone, the clamp assembly failed (broke)
A large crack is visible on the inner column of the clamp, and the heat set inserts appear to be slightly peaking out
The most likely suspect of failure is the large clamping force applied on the assembly or over-torquing of the bolts
The thin nature of features around the crack is one suspected cause
Next Steps:
More accurately define the root cause of failure
Perhaps using some FEA
Conduct a redesign while salvaging the unaffected parts
Author: @Jonathan Di Giorgio Date: 2024/01/22
1st redesign:
moved the clip holes outwards but its still pretty thin inwards
in order to make that thicker the options are
make the tube contact thinner (remachine the aluminum insert)
move the holes (re drill the frame)
its also possible that we may have just overtorqued the bolts originally and thats what caused failure
Author: @Jonathan Di Giorgio Date: 2024/01/24
2nd redesign:
Made contact smaller to add more thickness around the fracture region
Contacts and aluminum inserts to be reprinted and remachined
The top aluminum threaded plate may continue to be used (will remain functionally the same, but may be a little less aesthetically pleasing since it is not completely flush)