A good way for new designers to learn how things are made is to take them apart and see all the internal guts of everyday products. This can be a challenge for some as products are expensive and taking them apart voids warrantees and some fear not being able to put them back together. That's why I take some apart and share it on this page along with my youtube.
This is an amazon basic kitchen scale that I took apart before to show my client at the time Shopify what are the basic parts that go into a simple scale
This is a quick photo of a Bosch GSA18V-083B its known as a saber style reciprocating saw. I did not film a video of this teardown as I was opening it up quickly to diagnose why it had shut down while I was cutting some trees with it. I may revisit this tool and do a video calling out the different parts of the tool and what they do. As you can tell from the photo the designer of the tool did a pretty good job packing everything in with the only real open space being a bit in the handle around the trigger sensor wires and the power wires. You can also see that the tool does allow in a good amount of sawdust as no mitigation to ingress is applied in the design.