New Builder Questions

I am looking to build my first kart for MKE Makerfaire. I have a background in insect-weight combat robots. (I actually host all the events in Wisconsin.)

I’m trying to get some feedback before I’m hundreds of dollars into a design that can’t race effectively.

Viability Checks

  • ~$800 max total cost (not talking about the PRS budget)

  • Weldless live axle build (wood w/ metal reinforcement to hold important stuff like castor/kingpin angle)

  • 12s 18650 pack using these

Power Questions


It looks like I’m stuck with a 30A fuse for a 12s system. I see a lot of different motors being used and the racing still seems relatively close. What this tells me is that the wattage limit on these karts is what’s setting the pace. This raises questions:

  1. What makes a drive system faster than others?

  2. It’d make sense that you can spike past 30A for certain moments in a race. How do teams stay on this limit without blowing their fuses all the time?


Assuming there’s a competitive average wattage teams try to hold, what is the recommended battery capacity to put in a kart? Optimizing the minimum capacity to win sprint races seems like the most effective way to stack points in a weekend. I saw some builds end up around 45aH for a 12s pack. Is this about right?


This kind of ties into my first question about what makes a drive system faster than others. Alternators are tempting because they’re cheap, but again, questions arise:

  1. Why do most teams feel the need to run two alternators?

  2. What’s the minimum ESC recommended for alternators? Is it based on overall kart wattage regardless of motor?

I know this is a ton to ask, and I’m sure I’ll have more questions as I get farther into the project. I thank those of you who respond to any of these questions in advance. I feel like I’m really close, but bringing some experience into the mix will give me peace of mind.