What kind of DC motors + battery do I need for my heavy robotic tank project ?ty

Hi friends, it's me again Mekaci that I came with lot's of questions to ask and bother you again, but I really need your friends' help once again. I hope that you help me about this topic too.

I finished most of parts in coding and mechanical components for my wireless control robotic tank project and I used Aluminum components in my project and after including the batteries later on etc too, it became heavy ( 35 kg ). I really need you fellow friends' advice to do everything correctly in my project.

The main concept that I want is this: " I don't want my tank's speed so slow but I want my motors to handle the tank's movement smoothly on the ground or while climbing the 45 degree slope on the bulges that when it stops at the middle of the bulge it will not go down ".

#So, my main question is this:
1)What kind of DC motors and battery ( volt and amper ) do I need for my 35 kg robotic tank project ?
**I was planned to use 12v 4A li-po battery but if you advice a stronger version please say and I will get it.

**I will use x4 dc motors and I have x2 "2×15A DC Motor Driver"s on me now too(2×15A DC Motor Driver - DFRobot).

#I have other questions are these:
2) Should I connect the all x4 motors to one motor driver ? or,
3) Should I split the x4 motors as x2 - x2 to x2 motor drives ?
Which one is the efficient way ?

**I used these metal wheels and tank plates too: https://ae01.alicdn.com/kf/HTB1E.R7OFXXXXcRXXXXq6xXFXXXu/Mato-Metal-black-Tracks-sprockets-early-with-metal-caps-idler-wheels-with-bearings-for-Heng-Long.jpg. The radios of this wheel is like this: HL Tiger 1 49.82mm

#My last question are these:
**While I was checking the dc motors, I was encoder dc motor version and it seems it requires lot's of pin slots too in arduino for every dc motor and more detailed coding while using them too. Anyway,
4) Should I use encoder dc motor or normal dc motor to control my tank's movement in my project ?
5) What is the advantages and disadvantages of using encoder dc motors ?
6) Is it easy to use and code the encoder x4 dc motors in arduino ? Never used it before.

#I plan to buy dc motors from this website: MOTION - Motors & Accessories - HD Premium Planetary Gear Motors - ServoCity .
7) Thus, from this list which dc motor should I need ( normal dc version or encoder version too )? thank you.

Note:
**I was tried to use this dc motor calculator: https://www.robotshop.com/blog/en/drive-motor-sizing-tool-9698

**However, I was not quite sure so I wanted to talk with you friends and get real advice. I can buy the things you will say for one time. I am a student after all so I really need your help, thank you very much. Take care yourself and have a nice day all.

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.

I don't want my tank's speed so slow

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.

This site has lots of very useful information on robot design and construction, including how to choose motors and gearing.

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.

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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.

I wanted to learn what is the minimum rpm and torque do I need per dc motor to move my 35 kg robot tank.

See reply #2, linked web site.

I followed this website tutorial : How to Build a Robot Tutorials - Society of Robots

Then I wrote the values I desired at this calculator : How to Build a Robot Tutorials - Society of Robots

I got these values from that calculator:

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I didn't understand one part so much from that calculator result. According to that calculator what kind of dc motor do I need now ?

Note:

This is the website I am going to order the heavy duty gear dc motor too: MOTION - Motors & Accessories - HD Premium Planetary Gear Motors - ServoCity

According to that calculator what kind of dc motor do I need now ?

A brushed DC motor, with torque and RPM that produce the required RMF and that runs on the appropriate voltage.

You have already filled in some values in the table Enter Motor Characteristics: 30 kg*m (a very large torque) at 416 RPM (pretty fast), which gave you RMF = 208, about 5 times higher than required.

Where did those values come from?

jremington:
A brushed DC motor, with torque and RPM that produce the required RMF and that runs on the appropriate voltage.

You have already filled in some values in the table Enter Motor Characteristics: 30 kg*m (a very large torque) at 416 RPM (pretty fast), which gave you RMF = 208, about 5 times higher than required.

Where did those values come from?

At this link,

You see three sections. First you fill the Desired Robot Inputs yourself and then ,secondly, it gives you automatic values according to the written inpunts in the RMF Results. After all of these, you write your dc motor specifications in the Enter Motor Characteristics.

RMF = Torque * rps ( rps is rpm ).

At this link How to Build a Robot Tutorials - Society of Robots he explained in detail. I followed the tutorial then according the dc motor examples I was trying what is the best for my rc tank but still I am not quite sure if the 437 rpm with 22 torque or 313 rpm 30 torque is good for my heavy tank project. 313 or 437 rpm is still quite fast right ? thank you.

I wrote efficiency as %63 because I added the friction situations too otherwise in theory the efficiency should be %100.

This is the link for gear dc motor I will choose ( Heavy Duty Gear Motors > Premium Planetary Gear Motors ), please look yourself too thank you MOTION - Motors & Accessories - HD Premium Planetary Gear Motors - ServoCity.

still I am not quite sure if the 437 rpm with 22 torque or 313 rpm 30 torque is good for my heavy tank project.

In the photo posted in reply #5, you entered the values 416 RPM and 30 N*M torque.

Are you wondering whether a motor that is five times more powerful than required is not "good enough"?

jremington:
In the photo posted in reply #5, you entered the values 416 RPM and 30 N*M torque.

Are you wondering whether a motor that is five times more powerful than required is not "good enough"?

As I said before, at my previous robot tank, it was moving nicely ( on the theory and on the experiment environment ) but once it came to carpet at our house, it struggled while turning left and right ( you can see from the video link I shared you at my above comment ). This one is much heavier so I wanted to be sure while buying the right gear dc motor that it is quite expensive and I will give shipping cost, custom cost, and wait a few weeks to get in from United States to United Kingdom ( the pieces I want are not selling at robotshop uk and active-robot websites currently; so I wanted get someone's approval for being at ease before ordering the gear dc motors.

The tank's back and front tracks are separated between each other so it gives me an opportunity to use x4 motors at my tank, like the first robot tank I made before. Shortly, this is my next question:

Should I use x2 motors or x4 motors as using x1 motor driver with one battery on the one arduino mega board?
or
Should I use x2 motors to connect one motor drive and other x2 motors to other motor driver and connect them to the same arduino mega board ?

Your design does get in the way of easy turning.
The long, skinny base has to do a lot of skidding to rotate.

vinceherman:
Your design does get in the way of easy turning.
The long, skinny base has to do a lot of skidding to rotate.

vinceherman, if you read all comments and thread itself. Would you give me some advice/suggestion and help me to choose the right gear DC motor please ?

Shortly, which dc motor should you suggest me for my project from the given list at this link MOTION - Motors & Accessories - HD Premium Planetary Gear Motors - ServoCity? thank you.

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30 kgf.m at 418 rpm is a massive figure, bears no relation to reality. about 13kW of power in fact.

The power needed to propell 35kg up a 45 degree incline at 1 m/s is 240W (not including losses),
so I suspect a sensible power requirement is more like 500W than 13,000W...

If the wheel radius is 5cm (guess), with 500W mechanical power, then 1m/s equates to 190 rpm and 25 Nm
of torque (total for all drive wheels).

So what top speed do you want?

MarkT:
30 kgf.m at 418 rpm is a massive figure, bears no relation to reality. about 13kW of power in fact.

The power needed to propell 35kg up a 45 degree incline at 1 m/s is 240W (not including losses),
so I suspect a sensible power requirement is more like 500W than 13,000W...

If the wheel radius is 5cm (guess), with 500W mechanical power, then 1m/s equates to 190 rpm and 25 Nm
of torque (total for all drive wheels).

So what top speed do you want?

I am building this robot tank project to make demonstration for my final year project in the university. I didn't think in much detail before. I don't want my tank to be very slow but in a normal speed and pass the slope obstacles easy at 45 degree. What is your suggestion for me ? I will buy the gear dc motors from this website: MOTION - Motors & Accessories - HD Premium Planetary Gear Motors - ServoCity , I will be happy if you help me to choose the correct one, thank you.

What kind of Li-po battery do you suggest, according to the dc motor you will give advice to me ? and I plan to use 4 dc motors this time; because the tank tracks are separated between each other on front and back ones already. I will not do the same mistake with my 1st self robotic tank.

Thank you very much for replying and helping me too.

I am building this robot tank project to make demonstration for my final year project in the university.

At the university, you should have learned to think these things through by yourself.

We have been telling you that your selected motor characteristics are far too powerful, and giving you other good advice but you don't pay attention.

Why should we finish your project for you?