I made a sensor which allows a computer to measure force. It can tell you (80 times a second) how hard something is squeezing or stretching it with an accuracy of around 1 pound, up to at least 3000 pounds. I machined the metal structure of it, built the electronics to interface with the sensor and communicate wirelessly with a computer, as well as wrote a python program to easily read and interact with the sensor on the computer using a graphical interface.
This was the subject of my senior physics thesis. I gave an hour long presentation to the physics department during the fall of 2017, and the PowerPoint (actually Google Slides) for that talk can be found here. In addition, I made a poster for the project, and that can be found here. If you just want a summary of the project, the poster is a good bet.
The inspiration for the project came from the rock climbing cam that I made, since I wanted to be able to measure how strong my cam was. When I started the project, I couldn't find a strong enough force sensor for a reasonable price. I expected (OK, maybe hoped) that my cam would be able to hold around the same as a commercial cam, about 1400 pounds. All the force sensors I found that could handle that load were a few hundred dollars. I thought that making my own sensor was the only option. As I write this, however, I just googled again and found a 1000kg force sensor for $50, so turns out the whole thing was unnecessary. But whatever, I still learned a whole lot, and my sensor works just about as well.
So, in ignorance of commercially available options, I decided to make my own, save some money, get some more experience with machining, electronics, coding, and experimentation, and push the boundaries of what is possible to do DIY style. Using the sensor I was able to measure the absolute strength of my cam, some other commercially bought climbing gear, and see how much force various climbing falls generate.
There are four main parts to the project, each of which will get its own post on this blog:
-The theory of how a load cell works and how my sensor is set up
-The hardware and machining
-The electronics that act as the low level brains for the sensor
-The program that runs on your computer to read, display, analyze, save, and load data from the sensor
-The results of various drop tests in the Ritt Kellogg Climbing Gym
This was the subject of my senior physics thesis. I gave an hour long presentation to the physics department during the fall of 2017, and the PowerPoint (actually Google Slides) for that talk can be found here. In addition, I made a poster for the project, and that can be found here. If you just want a summary of the project, the poster is a good bet.
The inspiration for the project came from the rock climbing cam that I made, since I wanted to be able to measure how strong my cam was. When I started the project, I couldn't find a strong enough force sensor for a reasonable price. I expected (OK, maybe hoped) that my cam would be able to hold around the same as a commercial cam, about 1400 pounds. All the force sensors I found that could handle that load were a few hundred dollars. I thought that making my own sensor was the only option. As I write this, however, I just googled again and found a 1000kg force sensor for $50, so turns out the whole thing was unnecessary. But whatever, I still learned a whole lot, and my sensor works just about as well.
So, in ignorance of commercially available options, I decided to make my own, save some money, get some more experience with machining, electronics, coding, and experimentation, and push the boundaries of what is possible to do DIY style. Using the sensor I was able to measure the absolute strength of my cam, some other commercially bought climbing gear, and see how much force various climbing falls generate.
There are four main parts to the project, each of which will get its own post on this blog:
-The theory of how a load cell works and how my sensor is set up
-The hardware and machining
-The electronics that act as the low level brains for the sensor
-The program that runs on your computer to read, display, analyze, save, and load data from the sensor
-The results of various drop tests in the Ritt Kellogg Climbing Gym