AEAC 2025 Design Sprint
- Alison Thompson
- Evan Janakievski
- Smile Khatri
- Conall Kingshott
Big Project | Project | Project Manager |
|---|---|---|
Comp 2025 drone | Payload | @Alison Thompson |
Task Description
Add an entry with your ideas for how we should solve this year’s challenge! This can be sketches, notes, links, pictures, or anything else!
Entries
Author: @Conall Kingshott Date: 2024/09/21
Initial Ideation
Initial research on pumps seems to show that pumps on the scale we can fit in the payload have insufficient flow rate for our use-case. A custom peristaltic pump with servo power and multiple parallel flows could be worth investigating, but my designer’s instinct is that there is a reason they all have such low flow rates.
Peristaltic Pump 12V DC Miniature Laboratory high Flow 220ml/min Kamoer KHPP260 self-Priming Circulation Pump Small Liquid dosing Pump
As far as designing the payload without a pump, I believe designs with a hinged flap will struggle to be water-tight because you will need such a strong force to keep the flap closed with a long moment arm. The first design I’ve sketched out would be a cone in 3D with a top and bottom plate with some kind of o-ring or gasket. The red stage in this sketch is stationary. The payload is submerged in water in the first image. Air can escape out the top as it fills with water. Then, the black cone is moved upwards, creating a seal on the top and bottom. Then the black cone is lowered again to release water. Ideally this can all be rigged up to be controlled by one servo.
Below is a similar concept. It is less geometrically complex, but when you release the water, it will flow out at the edges.
Author: @Alison Thompson Date: Sep 21, 2024
Potential idea:
Computer cooling water pump, high flow rate like: Water Cooling Pump, 3000RPM PC Water Cooling Integrated Mute Water Pump Support PWM Intelligent Control Speed 800L/H Flow 3.5 Meters Pump Head PC Pump Tank
One in one out (if they can’t be run backwards)
Specification:
Material: Acrylic + ABS
Model: PU-FS4-J
Rated current: 0.7A
Rated function: 8W
Pump head: 4 meters
Pump : 800L/H
Starting voltage: 7V
The highest voltage: 13.5V
No-load speed: 5000RPM
Load speed: 3000RPM
Size: Approx. 5.5 * 6.4 * 6.4 cm/ 2.2 * 2.5 * 2.5 in
Weight: about 285 g
Author: @Smile Khatri Date: Sep 21, 2024
Using a pump would make manufacturing and assembly the easiest. Reduces complexity. Trying to submerge anything in water, especially if it is large and has quite a bit of surface area might be tricky.
Stealing Alison’s idea but diff. pump
Material: Plastic
Weight: 160 g
Voltage = 12V
Max pump head = 3 m
Type: submersible
Mount the pump to a rigid tube, and submerge it. A plastic tube can be connected at the outlet
Max flow rate = 240 L/h
this is equal to 4L/min
Total weight of Peggy 2 w/ batteries is 7350g. We agreed on a max take off weight of 12 kg 2024-09-18 Comp Arch Sync - Meetings - WARG (atlassian.net). This leaves us with 4.65 kg for water + storage + pump system.
If we limit max water capacity to 4kg, this would be about 4 L of water taking water density = 1000 kg/m^3. Ideally, it would take 1 minute to pump this much water which is a major drawback of this option. Depends on what time we are willing to accept. In my opinion, anywhere up to 15s is ideal a minute might be too much…
Could use a pump to expel the water from the tank but we can also just let gravity take care of this to maximize the mass of water the drone can carry. Will have to do maths to determine the flow rate .
Author: @Evan Janakievski Date: Sep 23, 2024
Two options that I could think of, and they both have been listed above. Helibucket or a pump.
For the bucket, there would be a worry about tangling the line or reeling in to make sure it is not dragging on the ground at lower altitudes.
For the pump, the mass of the pump needs to be taken into account as well as the volume that it could hold