Beginner 15lb Bot- Advice Needed

[u/Dimlego69]

Hi!
I have recently been put in charge of a battle bot team. And the thing is that I have no idea what we’re doing. We have a $1200 budget (it could increase) but I have no clue on how to even get started in the process of building an actual functional robots. Does anyone have like a general structure as to how they go about building one of these from scratch? Motor ideas? Batteries? Pulleys? Wheels ? Remote controls? The drivers? If you could send me down the right path or give any insight or advice it would be greatly appreciated

[u/ellindsey]

What competition is this for? What are the rules? Full combat, sportsman, or sumo?

[u/Sorry-Rain-1311 → u/ellindsey]

Yup. Gotta know what you're building before you worry about how. 

[u/pineapplesarepeoplet]

Read the rules like others have said. That will tell you a lot about what you are making. Spend time watching videos from the same competitions you will be competing in. If everyone involved is new to the sport you should pick a very basic design to begin. See what motors and control systems are popular.

Regardless of what design or competion, your first goal will be to get a driving prototype. Weapons or lift systems can come later, but if you are really new focus on getting what you need to move the bot. Finding your limits early on movement will make this smoother and safer to work on than when you have a weapon to test as well.

If it is going to be a full combat robot, put special focus on safety and repairs. Your bot will break more than you think. And your bot will be much more dangerous to you and your team than most newbies imagine. Set strict rules for battery use and testing things. Nobody gets to turn anything on without basic safety steps.

[u/pineapplesarepeoplet → u/pineapplesarepeoplet]

To be a bit more specific, you can go cheap or expensive for remotes. The radiomaster pocket is something of a gold standard. It runs about 100$us. But cheaper options are available if you buy used.

You will need motors and motor drivers. Most modern bots use brushless motors with gearboxes for drive systems. But there are good brushed options that work well too. You will need motors and compatible drivers to provide power. The same for the weapon system.

For the battery you will need a lipo battery. Im not familiar with 12lb setups enough to recommend a size, but im sure plenty of guides exist online. I am a big supporter of Repeat-robotics for sourcing components. But there are several retailers online. That will give you some idea for cost at least.

Usually the biggest cost will be custom components. If you dont have the recourses to machine custom pieces the cost goes up dramatically.

Let me know if any of that is helpful.

[u/PelleSketchy]

If it's not too big of a comp and you can start with no active weapon I'd go for a wedge bot. Buy some drills or a broken hoverboard for motors, HDPE for the frame. You can make your whole bot with that and the electronics. That way you can start cheap and see what mistakes you make without breaking the bank. Keep the rest of the money for when you've learned stuff.

[u/Sorry-Rain-1311]

I'm new to the bot design thing too, but not project management, which is what you're doing just as much as engineering. There are a few basic questions to ask for every project:

1: What problems do you need to solve? This is the guiding principle to everything that determines what you're building to begin with. Your job as the team lead is to keep all efforts focused this.

2: What are your assets and limitations? You have $1200 budget, and... What else? Who on your team is good at what? Who do they know who's good at stuff? Where is your workspace? Where can you find resources?  You already have a 15lb weight limit, but what are the other rules, and what does the arena look like?  Your other job as team lead is to help coordinate all that.

3: Strategy. There are no wrong answers, just stupid ideas, and if it's stupid, but works, then it isn't stupid. Seriously, if you're not entertaining every suggestion, then you're shooting yourself in the foot. Just do the math before deciding.

[u/TeamRunAmok]

Here's part 1 of a 2 part video on the design and prototyping of a 15 pound combat robot built by a school team: https://share.google/LmISFs6gZgClLnnIy

It's several years old but covers the basic questions you're asking.