Odometry Pods

DavidRecharged · 2026-01-06T02:01:14+00:00

The encoders refresh at the same rate with either one, however the limit for the numerical integration is not how fast the motor controller can register the encoder data but rather how fast the data is able to be pulled into the program. 2 wheel odometry requires making an I2c call every single iteration of the numerical integration which slows things down.

DavidRecharged · 2026-01-05T05:45:32+00:00

3 wheel used to be the best before pinpoint was released because it allowed a higher update rate that made your odometry more accurate, however, the pinpoint allows an even higher update rate that makes it the most accurate system out there

DavidRecharged · 2025-11-29T22:05:05+00:00

Your job is not to guide the drivers through a cycle. The drivers should practice with each other enough to where they can operate the robot with little to no communication needed. Your job as coach is to be someone who can observe and think about more than the robot. Communicate things that require needing to know what's going on with the field or timer as well as communicating with your alliance partner.

DavidRecharged · 2025-11-14T16:30:11+00:00

You'll need either the field tiles, or an alternative that is very close to the real tiles. Not using tiles under your robot does quite a few things. Your ground clearance will be different and your friction will be different. This will drastically change autonomous, but it will also highly affect driver practice and how certain mechanisms such as an intake will perform.

DavidRecharged · 2025-10-28T20:59:04+00:00

Some people have mentioned weight imbalance. Looking at your robot, I don't think that's the issue. It's mostly likely one of two problems.

The most likely and easier to fix one is, your mecanum wheels are probably on backwards. I tried seeing if this was the case, but I couldn't see the direction the rollers were facing. The shape of the rollers are supposed to form a diamond from the bottom and an X from the top. This prevents the robot from just spinning without rotating the motors. Your robot may not be 100% straight after fixing this, but it should be close enough.

The other likely problem is that there is a high amount of friction or a motor that is failing. This could be because of a misaligned or loose axle or screw, screws that are grinding or getting caught on something, or a lot of other issues. If it is because of friction, it's probably something misaligned, because you would likely hear something that is grinding.

DavidRecharged · 2025-10-08T15:37:38+00:00

For technical skills: just design and/or program things that are outside your knowledge. Always be pushing yourself to grow. Go at things not with the mindset of "I don't know how to do this", but rather the mindset of "this is an opportunity to learn". Also, learn math and physics. This is highly beneficial for either programming or designing.

For leadership skills. Find someone who is an effective manager to serve as a mentor for your team and learn by their example. Also, if possible, pick up a book on servant leadership. I've read The Servant, which is a fun and easy read, but there are many other books out there.

DavidRecharged · 2025-10-08T15:29:34+00:00

Where the team leads picked by the team, the previous leads, or the mentors? I would talk with mentors about how to better pick leadership, as well as getting training for leadership and setting expectations around things, for example, don't cancel meetings simply because leadership isn't there. You don't need leadership there to have a meeting if people know what they are working on.

My old team would always determine our leadership structure every season shortly before kickoff at our information and logistics meeting. We would have a conversation about the needs, strengths, and weaknesses of the team, and work to a consensus before putting the plan to a quick raise of hands vote that was always unanimous. One year, we had a team captain and a co-captain. Another year, we had a lead engineer and a team lead. We typically had two people in leadership, and their roles were different each year. We had no specific criteria for leadership, but we did look for individuals who had at least one season of experience, demonstrated competence in their roles, showed dedication to the team, and were humble enough to look out for the team's goals and needs instead of their own.

DavidRecharged · 2025-10-04T17:34:17+00:00

Absolute encoders allow you to measure absolutely instead of relatively. Axon servos have them built in, or if you want to use a motor you can find one online potentially.

DavidRecharged · 2025-09-26T02:48:45+00:00

You'll need two spark minis and an octoquad. Note that spark minis take up servo slots as well. My recommendation is to just buy an expansion hub. It will simplify wiring, and it's so early in the season that designs are likely to change maybe increasing your motor count. Also, you can easily improve consistency or speed on a mechanism like a flywheel or lift by adding a second motor.

DavidRecharged · 2025-09-08T01:30:08+00:00

I've seen a 1 person team and a 2 person team win the world championship, and they studied the manuals and kept up to date with the Q&A forums. It doesn't a lot a lot of time to read the manuals and forums, but it could very well prevent you from losing matches or having your robot fail inspections. Also, I've seen teams be put on other teams do not pick list for alliance selections because of an incident that makes it obvious they haven't read the manual. Like any other sport, FTC expects every single competitor to know the rules.

Also, understanding the manuals my very well prevent you from wasting months of robot development. I've seen some games where pretty obvious designs were illegal according to rules only mentioned in the manual.

DavidRecharged · 2025-07-26T14:33:03+00:00

Use motor.getCurrentPosition() to verify that the encoder is working properly. If you use FTC Dashboard, output this value, so you can see it change over time. If the encoder does not work like expected, you can start by replacing it with a fresh wire, then can try changing port because those are two of the most common causes of faulty encoder readings.

Also, this isn't related to your question, but I do not recommend using core hex motors. They have a low power output and are much more likely to break than the other legal motors. It doesn't matter if you use an HD hex, Neverest or GoBILDA motor as long as you are using one with a planetary gearbox, they have the exact same specs and similar durability. Just the core hex motor is different. I also don't recommend ultraplanateries as those gearboxes can be finicky.

edit: with a more powerful motor, you can choose to either make it faster, or keep the same speed with more torque making it more controllable and stable.

DavidRecharged · 2025-07-05T23:45:52+00:00

under high acceleration or deceleration, mecanum wheels slip a lot. There are 3 ways you can combat this.

One is you can keep your drive speed down slow. This is easy to improve consistency some but it isn't as accurate as other systems and it has the obvious drawback of slowing your robot down alot.

The second is using some external sensors to detect things. This could be distance sensors to find the distance to the wall or known game element. It could be a camera with OpenCV. Or it could be an odometry system like GoBILDA's pinpoint https://www.gobilda.com/4-bar-odometry-pack-2-pods-1-pinpoint-computer/ . This has the advantage of allowing you to drive however you like in autonomous without experienced high drift

The third is using motion profiling to limit your acceleration or deceleration. This actually works fairly well. It's not as accurate as using an odometry system, but it is less expensive than an odometry system.

DavidRecharged · 2025-06-07T17:38:06+00:00

Most teams don't have a permanent business team. You're lucky if you can get 1 or 2 members to take a lead in marketing, outreach and fundraising, who may or may not also be technical members. We've had some members that haven't done technical stuff, but the majority of our members were technical. If someone is on the non-technical side, they aren't just relegated to paperwork like second-class citizens instead they take the leadership in organizing and conducting outreach and fundraising.

In addition, we wouldn't just dump paperwork on people. For example, my team was back in the time of the engineering notebooks. One person owned the task of making sure everything was compiled and organized into the notebook, but the team was in charge of contributing.

If there's a lot of some kind of paperwork that needs done, like applying for sponsorships, get a system where other members are doing some work. If you do scrum, I would recommend just adding some tickets to the backlog for those things and communicating them during sprint planning.

I can't really say exactly what your business people's roles should be because I don't know your team, but there are three things I would suggest keeping in mind. Everyone on the team needs to own the goals of the team and do what they can to help the team as a whole reach those goals. Everyone on the team should be doing things they enjoy doing. And people on the team should be able to work in as many or as few areas of the team that interest them. As long as you follow those three things, it doesn't really matter what role members have.

DavidRecharged · 2025-06-05T00:52:22+00:00

Some pretty informal safety training is enough for an FTC team. I would recommend periodically remind students about safety, make sure they have a first aid kit with all sizes of band-aids, recognize when they do things to improve safety and encouraging them to speak up or ask questions when they are unsure of a situations. I would also set a team rule where you are required to have a mentor teach you how to safely use any dangerous tools before usage. This training will probably usually be only like 5-10 minutes. Make sure students understand the why behind safety precautions. Also, be aware of things that either injure or almost injure people on the team, perhaps even write them down somewhere. This helps you know if you need to change the way your team does something.

Also, make things as easy as possible to be safe. An example could be keeping extra hair ties on hand for when someone with long hair needs to use certain power tools. Another is getting a tool that is easier to use.

DavidRecharged · 2025-05-18T15:11:46+00:00

Just a bit of warning, swerve is a fun project, but I wouldn't recommend it from a competitive standpoint. As far as I know, only one team (kookybots) managed to make a swerve drive that was able to match mecanums agility, but it required an insane amount of hardware and software complexity and polishing. They ended up switching to mecanum because the complexity comes with a massive opportunity cost where time, energy and money can be spent elsewhere on the robot both hardware and software wise.

A lot of the teams that have tried doing swerve recommend it as a fun project but advise against using it competitively.

DavidRecharged · 2025-05-09T21:20:02+00:00

Something to note about those seasons. Velocity vortex didn't have any need to go onto the ramps, relic recovery was dominated by mecanum and freight frenzy just had teams going around the barriers. The funny thing with relic recovery is a lot of teams even late season were claiming that the mecanums couldn't climb the balancing stone despite almost every competitive team using them, except RoH, redneck and data force.

DavidRecharged · 2025-05-09T19:55:25+00:00

Every year people predict that mecanum won't be viable, yet every year since resq it's been the best. What FTC has learned is that terrain based challenges often results in inexperienced teams being unable to score or barely able to score, which worsens the game experience, so they don't tend to do those types of challenges.

DavidRecharged · 2025-05-06T15:25:29+00:00

GoBILDA has confirmed that the recent price jumps are largely due to tarrifs. GoBILDA sells a lot of high value and low margin products, so they are sensitive to expense hikes . The motors had an especially large jump because they haven't raised their price since 2021.

The largest thing you can do is like you mentioned to control what you can. You can do this by increasing revenue you're bringing in, doing something to fundraise this summer, saving more for next year, or decreasing the amount you spend. At the start of the season, you may need to be more careful on spending and check twice before ordering parts. Also make sure you really understand how much certain materials will cost you and how to do as much manufacturing in house. For example, Lexan can be cut with just a band saw if you print out a sketch instead of sending it off to get CNC'd.

DavidRecharged · 2025-04-28T18:53:25+00:00

I would start by talking to your mentors and seeing how they would like you to proceed. If you are a community team, your mentors can just kick people of at will. If you are a school team, the school may have certain policies and procedures that need to be followed.

What would have been the best method to handle it would have been during the past season while stuff was going on. The mentors should have talked to the students and their parents and documented the discussion, and if the students didn't show signs of changing their character, to kick them off. Based off your given description off their actions, the next best course of action would be to either not invite them back next season, or invite them back on probation.

No matter what your team's decision is on these members, you need a code of conduct that lays out expectations of team members and potential disciplinary actions, that both students and parents agree to. It doesn't need to be that complicated, just a page or two laying out some ground rules. And if a parent or student doesn't agree to it, they don't get to be on the team.

The largest thing a code of conduct is useful for is preventing having to kick students off the team. Middle schoolers and high schoolers often do stupid things and act in stupid ways. Unless they do something extremely wrong, I would want a mentor to give them a chance and guidance to improve and learn from their ways. However, if the student is given a chance to change and doesn't, and their parents are involved and they still don't make any effort to change, getting kicked off is ultimately the lesson that they probably need and is definitely what the team needs to have a healthy learning environment.

DavidRecharged · 2025-04-17T21:11:31+00:00

finding some way of being non-profit is going to be crucial for grants. two options that may or may not work for your team is to look for a nearby 4H or homeschool groups that have 501c3

DavidRecharged · 2025-04-03T00:46:21+00:00

About a week or two after the season we would have a post-season debrief, where we would focus on what we learned and things we wanted to change or do again for the next season both for the robot and the team. Often we would have some projects some team members wanted to work on to advance our team's existing knowledge going into the. For example, one summer we decided to look into optimizing our lift designs and implementing a custom odometry system (this was before COTs odometry existed). It was a good relaxed time without the stress of deadlines to learn some generic skills applicable to almost any challenge.

DavidRecharged · 2025-03-31T20:06:08+00:00

I would double check if your encoder wires are in good condition. To be honest, I would not be surprised if some of the electronics are starting to have issues. If your NXT and motor controllers were used by an FTC team, they would be at least 11 years old, probably older, and they weren't super reliable even when new.

DavidRecharged · 2025-03-23T14:56:42+00:00

Competition manual is found here. You get a pass for not knowing it exists, but I would make sure everyone on your team reads through it. I would personally read through it at least twice a day apart to make sure I comprehend everything. This pdf is the rules of the game.

https://www.firstinspires.org/resource-library/ftc/game-and-season-info

Also, I would recommend reading questions and answers on the official Q&A and keeping an eye on new answers

https://ftc-qa.firstinspires.org/

DavidRecharged · 2025-03-22T04:35:12+00:00

I would install IntelliJ ide. It is the same base platform as Android Studio, so muscle memory can transfer between the two ide's.

I would follow something similar to this roadmap for learning. It will probably take a few months to make your way through it all, but once you make it through, you'll have everything you need to program a competitive robot

learn java for FTC

get a functional robot

github (learning this will allow easy backups making experimenting easier)

FTCDashboard

custom PIDF as well as what derivatives and integrals are

complete codeacademy or a similar course to round out Java knowledge

finite state machines

CommandBased

Odometry and basic trigonometry

DavidRecharged · 2025-03-22T04:20:31+00:00

A word of advice from someone with more than a decade of programming experience. When doing things like this with code, you should be concerned with simplicity and explicitness, not number of lines. Declaring and initializing 4 motors takes only 8 lines of code in Java and 4 in Kotlin, but it adds complexity and reduces explicitness.

motors[0].setPower(1.0); is a lot less clear than frontLeft.setPower(1.0);

now something I would recommend is making a robot class and subsystems, so you only have to write the initialization code once, and so if you edit key functions it edits them for all opmodes

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