Lithion-Ion Batteries

[Jon Stratis]

Originally Posted by ToddF

I'm a fairly new mentor, so some of my thoughts may not be as seasoned as the veteran folks out there. I'm seeing some assumptions in some of the responses that I don't understand.

There seems to be an assumption that for something to be legal for use on a FIRST robot, 1) its performance needs to be completely characterized, 2) it needs to be supplied to all teams in the kit of parts, and 3) it replaces whatever components were previously legal.

Where I can see how this MIGHT apply to control system components running software, I don't see why it should apply to things like actuators. I don't see a downside in allowing brushless motors and drivers to be included in the list of options we consider. Maybe they aren't right for certain applications, but for others, they might be. Why not allow teams who want to use them to save money to do so?

AdamHeard rightly pointed out that the Jaguars (and Victors) are far oversized for the shooter wheels. So why do the rules limit us to using those and only those motor drivers? Why not allow teams to use other options?

Reading between the lines, it seems that at some point in the past, cheap motor drivers were not available, so in order to ensure a supply of reasonably priced drives, FIRST worked with suppliers to come up with custom motor controllers. To ensure that the market was large enough to keep prices down, they made rules that limited teams from using anything else. I would argue that the commercial marketplace for inexpensive motors, drives, and controllers has caught up and bypassed the needs of FIRST. Inexpensive, rugged motors and drives, both brushed and brushless, are commonly available in the RC marketplace. For the $285 cost of the cRIO FRC II Controller, you can buy EIGHT Raspberry Pi computers (I have an order of three arriving today.)

During build season, I'm all about doing the best you can with the limited set of components allowed. But, with cheaper, possibly better, components available in the commercial marketplace, why not expand the rules to allow us to use them?

Again, I apologize for hijacking the OP's thread. If anyone knows how to split this topic off into a new thread, please do so...

In order for there to be more options, FIRST needs to understand and support the characteristics of those options. Otherwise, you could run into some dangerous situations. Some examples:
- What if a team figures their mechanism only needs a couple of amps, so they use a cheap 5A speed controller? Who puts out the fire when something goes wrong and it draws 20A during a match?
- How do you handle the situation where a team picks a motor that has a grounded chassis? having any sort of short to the frame can cause some major issues, both for your robot and for safety on the field interacting with other robots.

Further, how do you ensure sufficient quantity for all the teams that want a particular part? It's great to say that teams can use any motor, but what happens when the veteran teams buy up the limited stock of the most powerful motors, leaving the rookie teams to suffer? Companies like Banebots, IFI, Vex, and AndyMark are very invested in the FRC program, they know the typical demand every year, and can help to ensure that all teams have access (even if there are occasionally shipping delays for a week or two) to the parts we need. If we go with "common" parts from suppliers that aren't invested in the program, you run the risk we've encountered with game pieces (like Orbit Balls!) in the past - the company stops producing them, causing problems for teams during the build season!

Also, please remember that one of FIRST's primary characteristics is Coopertition. How can teams help each other if their systems are all different? How can you borrow a speed controller from someone if they use something completely different, with a different footprint and different characteristics? How can FIRST possibly manage a FMS (field management system) that ensures equality and safety for everyone if everyone uses a different robot controller?


Some advanced individuals or teams may certainly have the knowledge, experience, and ability to test, develop, and utilize alternative controls. Most rookies don't. Even some older teams don't. FIRST does its best to provide a consistent platform for every team, so everyone competes on an equal footing.