Hello, below we will go over a few steps we use to create some of the research robots on this site. In this case we will be designing a 330 mm robot base to use as a test platform.
Some of the first things we need to do is think about the design of the robots head. This way we can visualize what we might want the robot to look like and or where to place the features. So imagine if you have a robot that needs to be able to put out a fire in a residential environment. In this example you have already set many constraints. The robot should be waterproof, large enough to carry a water supply or drag a hose behind it, Have the ability to climb stairs, and be small enough to travel though doors. There are many countless other items to think about though this is some of the things you should look into while making the first few sketches of the robot. With the design of the robot for this tutorial and that were building. We need to ensure that the platform that is not two big that it would become expensive, though large enough that it can carry a reasonable amount of battery power and a on-board computer. We found that base panels with a approximate diameter of 330mm worked best for this.
So after thinking about the design, take out a sketchbook try to sketch many different concepts and looks. Below are a few designs we have came up with.
After sketching the robot I like to visualize in 3D so I move to Google sketch-up. This program allows me to change the look and feel of the robot and get it more finalized. At this point I build or use the warehouse models to get a Idea if all the components will be fitting in the robot. In this way It allows me to catch issues with the design before moving on to a AutoCAD program. If many issues arise in your design during Sketch up I would advise going back and sketching different Idea’s on paper and repeating the process.
So you like how it looks in sketch-up and want to move forward with the design. This is where learning a AutoCad program really comes in to help with the final outcome of your robot or prototype. I use Freecad and or Draftsight auto CAD programs. I only have a small issue with these programs and its mainly due to the fact that I have had college training on AutoCAD Inventor. Inventor like SolidWorks just blows them out of the water as far as speed and usability. However there is a catch they are not cheap even for a student version. Use the best program you can afford as a quality program will allow you to design everything quickly in the 3D environment and weed out small mistakes. I will be displaying a few below for you enjoyment as I believe they are important for learning. Below is a few pictures of the 2mm aluminum base plates that comprising the robot base. As you can see there are a few issues that could have been resolved early on if I had created all the parts within the cad program. Do note none of these issues cause much alarm as they are ether fixable or aesthetics based. These will be updated and I will be posting a link to the CAD files below as this is a completely open source robot. Here is a link to the main page for this robot Nvidia Jetson robot
The servo does not really fit into the slot. I did not leave enough room for it to slide in at a angle easily. This is easily fixed with a bit of elbow grease and a metal file.
The hole for the aluminum tube is to small and does not easily slip over it.
It would have been nice if I moved this piece forward slightly as it would aline the head unit to the from of the robot and cover the points in the front. Also in this picture there is a great place to put a hole for wires to pass though the base though It slipped my mind that I had a tube on this side where wires come out of.
we could have move this up a bit as the cutout for the head unit has more room then really needed.