4tronix initio 4WD Robot Car Platform with Motors & Speed Sensors for Raspberry Pi or Arduino

I really recommend this start kit for any arduino / raspbery pi enthusiast. It make a nice project to learn how to make things run concurrently. It is not that difficult (I'd say a 10 yr old could make it... but the coding is a little more difficult)

Fun to buildPoor quality and weak motors.

I have no experience in robotics, and precious little in electronics, as I come from a software background. So, when toying with an idea, I thought this platform might be a good place to get started. My expectation is to end up replacing almost all of it, but this modular kit gives me the capability to slowly evolve the design rather than having to jump in head first.It's built reasonably well, and is straightforward to hack. The instructions aren't great, and there's a lot of Googling for various blog posts by the manufacturers to get vital information.However, the spec is terrible. The motors are extremely underpowered, unable to even start the rover moving unaided. Without any information on their specs, it's tough to know with what to replace them. I tried converting the rover as suggested by the instructions using four 28BYJ-48 stepper motors for greater control; the robot does move now, with the immediate torque of the stepper motors, but it's comically slow: 1.5 metres per minute, maybe. Am I missing something? Is it really meant to be this weak?The 6 x AA battery setup is optimistic to say the least. The tyres are relatively loose too, so I'm going to end up having to glue them, I think.Anyway, it's a fun platform to start with, and I've learned a lot on the way, but overall it just seems to miss something... maybe a better explained upgrade path, with suggested replacement motors, or explanation of how to develop it further. Or just a more realistic motor and battery spec to start with.

bonus features i hadn't realised was ability to replace dc with cheap steppers ... which i already had!tiny niggle is that you can get separate power to all 4 wheels but it only comes with 2 dc motors. You can drive all 4 from those 2 via gear selections, or make upgrades to get 1 motor per wheel