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Posting details on my engineering design projects. More at https://www.instagram.com/djrohu.engineering/

In the last blog post I shared some of my initial plans and the components of the machine that I had been working on. After a lot of trial and error as well as editing the design of some components, I eventually managed to come up with my final Rube Goldberg Machine and it works! As always I am going to talk you through the design process of the setup before showing off the final video, but feel free to skip ahead.

I am going to start by showing a clip of the final setup and then explain the various…


The next project I am working on now is the design of a Rube Goldberg Machine. These machines are built to complete a simple task in an extremely overcomplicated way. The purpose of these machines is not to be practical or efficient in the manner it completes its task, as seen with the last few projects discussed here, but simply to be fun and entertaining.

Rube Goldberg Machine Example

This is a nice change and gives a lot of free reign on what I can do with my design. It doesn’t however mean that there wont be careful design and planning involved as I’m…


After lots of weeks of planning and preparation today we find out if the Tumbller can make it through the maze (obstacle course) and if I can manage to net any ping pong balls in the process. This is the final layout from the Tumbller's point of view with the bottles now in place to fire the ping pong balls over.

There have been a few changes I made to the Tumbller though that I want to talk you through before we look at the attempt. First of all I had to rebalance the motor speeds as the Tumbller was…


Hi all, again a lot has happened since my last blog post and I am looking forward to going through it all with you now. Last time I hinted at some plans to have the Tumbller go through an obstacle course. This is the drawing given to use which we are meant to replicate at home.

Some of the dimensions have been relaxed since the initial brief but nothing too major. The objective is for the Tumbller to go from start to the ball collection zone and stop there for 20 seconds. I will then try to fire in as…


I know it has been a while since the last blog but a lot has happened since then which I’m excited to talk you through now. I am happy to report here that the Tumbller robot finally did arrive and I was able to collect it and bring it home last week. I was worried for a while that it might not show up at all this college year and that we would have to finish our design module with next to no physical design. Thankfully this isn't the case though.

Building the robot was actually quite fun and took…


In the last blog post I went through my thoughts on what type of stabilisation attachment I wanted to use for the Tumbller. I ended up choosing to design a caster wheel for a number of reasons you can find in that post. There were however still a lot of details I needed to figure out before drawing up the CAD file of my design.

I had no idea until recently but there are actually quite a number of different designs for caster wheels. They aren’t too dissimilar to each other, but enough to make a difference in mobility and…


After building the ping pong ball launcher, the next small project I started working on was designing a mechanical attachment to stabilise the Tumbller. Yes, the robot still hasn’t arrived and it is looking increasingly like it might not at all. This however doesn’t change much as I can still implement my design by adding it to my CAD version of the Tumbller. The original plan was to have the robot travel through an obstacle course which would be quite difficult simply using its self balancing functionality. This is the reason for the stabiliser. The brief was kept very open…


In my last post I was still unsure about which spring launcher concept I wanted to go with as I had doubts about how well the small compression springs I had at home would perform. Between now and then I was able to gather some materials and work on what sort of design would be feasible for me to build. I wasn’t able to find any other springs (compression or tension) so I had no choice but to use the the ones at home. …


Between my last blog post and now I have done a fair bit of thinking about which design concept to go with for my ping pong ball launcher. Check out my last blog if you want to find out what my three design concepts were. To come to my decision I obviously looked at which design might perform the best but also how feasible it would be to build the model with what I can find at home. I am going to walk you through my thought process and some comparisons of the different designs here.


At the end of my last blog I started to describe what the next small project I’m working on is. You can check that out for a little intro if you haven’t seen it but basically I am going to be designing a ping pong ball launcher to fire the balls into a container on top of the Tumbller (if it arrives in time). The project brief states that the launcher should be an energy storage device that converts potential energy into kinetic energy when releasing the balls. …

David Rohu

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