vinceherman:
Why 4 motors?
Most tanks I see use one motor per tread.
I suppose that if they are mechanically linked, 2 motors could be used for a single tread.
This is an arbitrary requirement. What is slow?On #1, if 12v is the right voltage, get any 12v battery. After that, the number of AmpHours just correlate to run time. If your tests indicate that the battery runs low too quickly, add more of the same battery in parallel.
I wanted to learn what is the minimum rpm and torque do I need per dc motor to move my 35 kg robot tank.
I was built a wireless tank long time ago as using ps2 joystick and I was having trouble with my tank while climbing the bulges because after some degree it was going down or there was not enough torque to move it up at some obstacles; because of its weight. Apart from that I was having difficult while turning the tank to left or right ( carpet has lot's of friction ) so it slowed down the tank so much. And if the ground is too smooth, it was hard to move because the it is slippery ground ( very smooth ). That tank I made like minimum 15 kg. At that time I didn't have nice components and I used the pieces I had and made extra mechanical parts, modifications all myself and built this tank within 3 months. PS2 joystick was so problematic at some parts but I learned how to solve problems I encountered.
This is a small video demonstration I was made long time ago: https://www.youtube.com/watch?v=7hyX7i5QyR4&t=42s
The current tank I make now is much better as its look and as functions with more features which I build in UK now. But I didn't want to make the same mistakes I had made before while I was in Turkey in my home ( I studied mechatronics in Turkey ). I am in UK now to study AI and Robotics as 2nd year student ( it is my 2nd university ). I want to improve myself in robotics and I like to work,try and study myself first and make real life applications to learn faster ( theory and real life versions are not exactly same, so in my opinion, to learn these practice in real life is important too ). Before I come here and ask you questions, I try myself in my room first and if I fail then I am coming and asking questions. So, I will be very happy if you guide me and teach me. I am hunger to learn really, thank you.