Final Project
Overview
I already knew what I was interested in making for my final project before Fab Academy 2025 began. It's an idea that has the potential to, at best, change the world, at the least, be a gimmicky product you see on Temu.
A toilet seat that lifts itself and puts itself back down. But, why?
Over countless dinners I have explained to friend and foe alike about how I believe we can change the world through the reduction of small scale inefficiencies. If we reduce tiny (fricticious) issues in our lives, at scale, we can begin to heal the world (one bathroom at a time).
Since the advent of toilets, man and woman have battled one another, both internally, and externally. Men cannot aim, women have to sit, we share the toilet, but men must lift the seat AND put it down. A cruel world we live in, indeed.
If I am to be both a proper gentleman and a germaphobe, then I will do it my way.
My proposed solution:
The Shit Flip aka Die Pisbrug
This is what I was able to make before I started Fab Academy.
Brainstorming
Some very early sketches...
More brainstorming...
Toilet seat lifter
What kind of motors / hinges / levers I could use?
After some initial research, linear actuators seemed like a good option. My linear actuator idea would probably need a base that sits on the ground.
I like the idea of the linear actuator because it would minimize contact with the inside of the toilet, but it would also make the final design bulkier.
Here's an idea of a manual toilet seat lifter that the linear actuator motor could replicate.
This is a sketch for a rotating joint.
The sketch below is an idea I had that doesn't have a based on the ground. However, it will be a struggle to clamp the piece on to the toilet without having to hook into the inside of the toilet bowl.
In order to help lift the toilet seat, a counterweight could be handy.
Linear actuator resources:
- Linear actuator kit
- (Actuator) elevator gear
- Lead screw actuator
Motion sensor
I plan to make a 3D printed part that will house the sensor and can communicate with the toilet bowl lifter. It will attach to the under side of the toilet bowl with a suction cup.
This is an idea that I think would more likely sit in Spiral two.
Gravity
Henk was very early to point out that I must consider gravity. All further design considerations take that into account.
To address that, I studied up a bit on motors and torque as I want to better understand the dynamics behind how we get objects to move.
Here are some useful resources around motor types, gear ratios, and torque.
Design
After familiarizing myself with the types of mechanics and components I might use for my project, eventually I had an idea that seemed promising.
My plan was to:
- Make use of the space between the seat an the wall / cistern
- For stability and positioning, incorporate the two bolts that hold (most) toilet seats to the bowl into my design
- Power my device with a stepper motor (or two) for the lifting of the lid
Combining all of those points with a mechanism like this draw bridge that I saw on YouTube. I hope to use the rotation power of a stepper motor to wind up cables that are attached to either side of a toilet seat.
NB. Do make sure to look at this rotation driven draw bridge
My first design incorporates the two bolts of the toilet seat and is designed to sit behind the toilet seat.
99% of toilets that have seats are held in place by two bolts. There is a space between the seat and the toilet that I hope to utilize to lock the base of my design in place.
As I plan on pulling the toilet seat up by cables, the motor will be pulled forward. The bolt slots hope to counteract that.
Midterm work plan
I have now been introduced to most of the theory that I will need in order to design my final project. It's now about compiling what I've learned and putting it towards making Die Pisbrug.
My plan is as follows:
(one) Test stepper motor strength
- Lasercut / woodwork a base that can hold a stepper motor
- Test how much weight a stepper motor can pull up
I will attach a string to the stepper motor and have it a) pull objects across a table and b) pull weights up a pulley system.
The results of these tests will help me figure out if I need two stepper motors and how much power I will need, or if I need go a different route entirely.
(two) Design
It's important that I turn my notebook sketches into 3D models so that I can use the lab's tools to make prototypes.
These are some areas of the design for the final project that I need to figure out:
- How to attach string to stepper motor?
- Nut and string holder
- Outer wings to thread cables through?
- Non-slip mat
- Toilet clamps
(three) Material decisions + production
- Power and control
- Sensors (spiral two)
- Communication protocol?
- What material will the base / clamp / cables be?
Spiral 1
- A stepper motor that receives communication from a button to lift a toilet seat
- And is able to lift the toilet seat and put it back down
- It's all held together with a base plate
Spiral 2
- Toilet seat clamps
- Sensor activate (TOF, milliwave, etc.)
Spiral 3
- Adjustable base plate to fit different sized toilets
- Magnet controlled release (seat + lid vs. just seat)
Project parts
Case
Cable
- Fishing tackle
- Quentin's 2-axis machine cables
- DM20 rope (low creep)
Seat clamps
Here's a tutorial on YouTube for making a simple clamp in Fusion.
The clamp needs to clamp the lid and seat when lifting in MALE URINATE mode but just the lid in all other modes.
I decided to put a servo on top of my clamp and have it turn a flat part inward when MALE URINATE is chosen.
Later spiral: Magnetic
Power supply
Button or sensor case
- Milliwave sensor
- TOF sensor
- Step response (Adrian's suggestion)
Electronics system diagram
Mechanical
Testing the capabilities of the stepper motors.
insert video of it going up
After a few beers, Henk convinced me that a gear system would help lift the lid. The next day, I tested that in the lab.
Fabrications
Questions?
- How do I power the device?
- How do I stop moisture getting in?
- How do I get electricity to the servo clamp?
- How do I make the battery detachable? (later spiral?)
- Do I use a CNC shield or make my own circuit?
- What components are needed?
- What do I use for the structure?
Integrating Fab learning
Computer Aided Design
In Computer Aided Design week I learned how to use CAD softwares to make digital designs. In that week I followed a tutorial to make a toilet in Fusion. The skills from that week are essential for the creation of the toilet seat lifter I'm planning.
Computer controlled machining
3D printing
Input devices
Sensor work
Output devices
Servo turning
Extra questions
- What to do about soft close hinges…?
- Detecting men vs women?
- Toilet seat lifting quick enough so that it isn't irritating to wait for
- Closing toilet seat quick enough before flush (for those who don't like toilet spray)
Who's done what (already)?
- Toilet seat lifter project - Kochi
- Toilet rolls (I like the idea of magnets, somehow)
- Household hacker -- string lift
- A toilet seat that always stays up + their YouTube
- Self lifting toilet seat (entire seat)
- Spring-Mounted vertically Held Toilet Seat
- Cleana
And my personal favorite:
- Flush seat goes down
- And this is their website
What didn't work?
What worked? What didn't?
Bill of Materials (BOM)
What materials and components were used? // Where did they come from? // How much did they cost?
| Materials | Sources | Costs |
|---|---|---|
| fishing tackle | Gamma | XXX |
| NEMA 17 | XXX | XXX |
| ESP 32 | TinyTronics.nl | XXX |
| XXX | XXX | XXX |
| XXX | XXX | XXX |
| XXX | XXX | XXX |