Centre of mass finder how to#

You can get away with a much simpler board (or microcontroller). But I would say that Teensy 3.1 is overkill for this project. You can choose from a variety of prototyping boards like Arduino, LaunchPad, Teensy, and etc. So I will just describe what I did and what parts I used.įirst of all, you need a microcontroller. Unfortunately, I will not be able to give you any in depth explanations and tips in this part, since I myself am in the process of exploring that exciting field. I am not an electrical engineer or programmer.

Centre of mass finder how to#

If someone gets interested in building an indication system like the one I did, I may write another guide explaining how to build it.īefore we move on to the electrical/programming part, I want to emphasize some of the most important points considering the structure of the device: I will not describe it here, because it is a totally different story. Actually, it was the most difficult part of the project. I used a laser pointer controlled by two stepper motors.

You can print it on a piece of paper and then glue it to the platform. The simplest solution is to draw a mesh with coordinates on the platform. In this last step of the construction, you need to think about what indication system you want to use. Also, this type of connection lets you adjust the position of the platform, which will help you to level the platform. If you do not tighten the cap nut too much, we can say that the moments at the supports are negligible for our application. Note that the diameter of the washer is much smaller than the size of the platform. If you have a single hole in the center you can put the bolt directly through that hole. In this way I avoided twisting of the load cell. Here I used a small plate between the load cell and the platform because there are two holes at each end of my load cell. There are numerous possible designs for the base frame. Otherwise, it is easier to have the dimensions between the supports fixed. I guess, it is a reasonable thing to do if you have something really big to measure. You may choose to have your load cells separate. The next step will be to design a base frame that will connect everything together. Load cell capacity=FS*(mass of object)/(number of supports) In general, you can use the following equation with the different values of FS (factor of safety) depending on the type of objects you are going to measure: There is a trade-off between universality and precision. In this case, you will not need to think about how to position the examined object that its CG is closer to the center of the platform, but you will experience some loss of precision and sensitivity. You may want to be on the safe side and choose load cell capacity to be larger than the expected maximum mass. The closer the CG to one of the supports the higher capacity load cell will be required for that support. You need to estimate how uniformly the mass will be distributed between the supports.

Then knowing the maximum weight, you are expecting to measure, you can choose what load cell capacity you need.

Ok, let’s divide the whole process of designing the device into steps.ĭetermine the mass range of the objects you want to measure.