Nobody is arguing that building is not a good experience. We're just trying to point out that COTS helps teams use less resources which means they can use their resources better which means they can build a better robot. Even teams who work extreme hours with extreme resources can benefit(hint hint 254. Their drive gearboxes used quite a bit WCP parts from what I heard and vex gears replaced the custom ones they used to make. COTS is allowing them to build better/faster.)
Today I received an email from a sponsor that happened to pertain to this. This is from a sponsor with a lot of resources machines(
This picture accurately depicts their facility. This is only a small part of the entire facility). This exerpt regards the use of prefabbed parts in industry:
#1 – Something anyone in engineering needs to keep in mind at all times is a tried and true saying: “Don’t reinvent the wheel”. Even though it is easy to understand, it is very easy to fall victim to. If you are indeed going to all of the work to design something, before you start, make sure it doesn’t already exist elsewhere (this would apply to levels from a single component, all the way to the end product). Even if you end up going through with a new design, knowing what is out on the market already will help you do it better the first time around. Additionally, if it doesn’t already exist, there may be a very good reason for it.
#2 – Whatever you make, use as many off the shelf components as possible. This not only helps with development costs & lead times, it also provides a much easier ability to get repair parts down the road significantly faster & cheaper. Also, if you need to recreate something custom later on, ideally you will have the respective print for it too. Without that print, then you have to re-engineer a custom part, which may not be as successful as the initial one, and will cost even more.
Back on topic, I don't think that water jetting is a good process for a part like this. Drive gearboxes are important parts of your robot, that get a lot of use, so tolerances are important. You will not be able to achieve the required tolerances with a waterjetting machine. All of the 1/4" Al gearboxes I have seen have been done on CNC machines. Also, we use .1875" thickness outside of our bearings(.625" radius for .875" OD bearings, .75" radius for 1.125" OD bearings).