For some reason, most people find the mechanical aspect of robotics extremely terrifying. They feel the need for extremely complicated and expensive equipment. So, I decided to list out all the basic mechanical tools and cheap hacks you can use in your workshop or makerspace to build simple robots and other projects. Most of these tools can be found around your house. Some of them can also be borrowed from your local mechanic or repair shop or be found at the closest makerspace. For more information on makerspaces, check out this post!
Ordinary scissors, box cutters, and a hacksaw. You can use the hacksaw when the box cutter fails to do its job, otherwise, I would just keep the hacksaw in a safe place away from humans as it can be a hazard if not stored properly.
Grabbing and Clamping Tools
I would suggest you curate a set of different pliers, such as needle-nosed, the kind that cut, as well as the flat stubbed ones. They are some of the most multipurpose and helpful mechanical tools ever. Apart from the pliers if you have one c-clamp like holding device. you should be all set. Bench vices are overkill but are useful to have in some situations. You can always go to the local hardware store if you need one.
This is a very important category, you should ensure that you have at least one proper ruler with visible markings and if possible, get your hands on one of those cool retractable measuring tapes that you see in the hands of your interior decorator every now and then. PS: I got mine from him.
Obviously, no justification required for these. Get yourself a pen, pencil, sharpie, or whatever you fancy and stick it behind your ear unless you want to lose it!
Hammers and Mallets
Every now and then you might need to scavenge for parts from waste material and break some parts off. This is when hammers and mallets will come handy.
Screwdrivers and Fasteners
Of course, you will need a good collection of screwdrivers so that you can open all the screws you can find around your house. Household E-waste is extremely useful, learn to hoard it and harvest it for free motors, power electronics, and other such things.
Also, try to curate an assortment of nuts and bolts from all these things that you unscrew. They can be extremely helpful at times.
Zip Ties and Duct Tape
Notice how I haven't grouped these two in with the other items? That's because they are the Gods of hacks and I literally worship these two things. Zip ties and duct tape can literally be used anywhere to fasten and or hold things together temporarily or permanently. You never have to worry about things falling apart if you have zip tied or duct taped them together. These are fool proof methods of putting things together. They are definitely the best 'Jugaad' ever.
These are mechanical tools such as drills, hand cutters, and dremels. They are rarely required and can always be borrowed from your local mechanic. This approach saves you a lot of money as well as space.
So, now that we have the basic mechanical tools and equipment sorted out, let's try to understand what the mechanical domain is all about. The mechanics behind robots can range from extremely simple jugaad to uber complicated mathematics and formulae involving forward and inverse kinematics as well as other aspects. For starters, you can try to 3D model parts for robots. There are a number of free and/or open-source software programs available for this purpose. You can try using Sketchup Make which is the perfect 3D modeling software for noobs. There are a lot of easy to use tutorials available as well.
Recently, there has been a huge boom in the rapid desktop prototyping industry that led to the creation of digital mechanical tools like desktop 3D printers, laser cutters, and CNCs that you can use to build professional looking parts, but those come later. For a start, we can just use simple parts that we find around the house.
Two of the major things that you might want to keep in mind while designing/building your robot are the size and the weight of the robot. Things require power to move and the larger and heavier your robot is the greater its power requirements are. Hence remember to do a rough torque calculation on your design before you get started building it. This can be done by estimating the center of mass of your robot and then measuring the distance between the center of mass and the motor shaft. As torque is the product of distance and weight. Multiply the distance by an estimated weight and check if your motors can provide such torque. If not, consider changing your designs or try using more powerful actuators!