Need help with choosing motor.

[Sasakii]

Hey.

I would like to start a project of building an rc car with a drone motor on each wheel. They need to be rather small and have lots of torque, because its probably necessary. I dont really know where to start, is there something of a unite for motor size, or what do i have to look out for for torque.

Thanks for the help

 

[Stu]

Why would you want to put motor on each wheel? Have you thought about how you intend to sync the 4 motors and how to achieve steering. Taking a sharp bend would need each motor to be turning at a different speed, You'll need some pretty sophisticated hardware and software to do that. Plus the ingress of dirt, gravel and grit into the motors would be a major headache, unless you'll be running on a spotless race track indoors.

How about the drive to each wheel. Will the motors be coupled directly to each wheel or will you be using gearing? What about room, you'll need either 4 ESC's or a 4 way ESC and hi torque motors will need a battery able to give maximum power immediately. It will have to power those 4 motors, plus the electronics. You'll have to consider size and weight. What will you use to stop wheel spin at initial takeoff? You're going to want a fast getaway and that introduces yet another headache. Will you need cooling? If the ESC's require cooling you'll need to channel air to each unit using a substantial fan to allow being split 4 or 5 ways.

Using High Torque motors will mean a beefed up chassis with beefed up steering, wheels etc. This will add extra weight which means extra power (bigger Battery) which will add to that weight which will mean a stronger chassis. You're going to need either a diploma in engineering or to hire someone who can design this project for you.

Then you'll have to control it all, again you'll require sophisticated hardware. I doubt you'll find anything "Off the Shelf". Do you have the tools to make the custom parts. A lathe would be number one.

There are thousands of different brushless motors on the market. Without knowing the eventual weight involved it's impossible to guess which one will do the job. But to kick you off in your quest you're going to need a brushless motor with a large diameter and short axial length. This type will deliver the best torque. Tell me, why are you driving all 4 wheels. It's not going to give you more speed, the fastest commercial model car from some years ago used the standard 2 wheel RC configuration. I still own this car and it was rated at 100MPH out of the box. It was powered by a Nitro engine.

 

[Sasakii]

Why would you want to put motor on each wheel? Have you thought about how you intend to sync the 4 motors and how to achieve steering. Taking a sharp bend would need each motor to be turning at a different speed, You'll need some pretty sophisticated hardware and software to do that. Plus the ingress of dirt, gravel and grit into the motors would be a major headache, unless you'll be running on a spotless race track indoors.

How about the drive to each wheel. Will the motors be coupled directly to each wheel or will you be using gearing? What about room, you'll need either 4 ESC's or a 4 way ESC and hi torque motors will need a battery able to give maximum power immediately. It will have to power those 4 motors, plus the electronics. You'll have to consider size and weight. What will you use to stop wheel spin at initial takeoff? You're going to want a fast getaway and that introduces yet another headache. Will you need cooling? If the ESC's require cooling you'll need to channel air to each unit using a substantial fan to allow being split 4 or 5 ways.

Using High Torque motors will mean a beefed up chassis with beefed up steering, wheels etc. This will add extra weight which means extra power (bigger Battery) which will add to that weight which will mean a stronger chassis. You're going to need either a diploma in engineering or to hire someone who can design this project for you.

Then you'll have to control it all, again you'll require sophisticated hardware. I doubt you'll find anything "Off the Shelf". Do you have the tools to make the custom parts. A lathe would be number one.

There are thousands of different brushless motors on the market. Without knowing the eventual weight involved it's impossible to guess which one will do the job. But to kick you off in your quest you're going to need a brushless motor with a large diameter and short axial length. This type will deliver the best torque. Tell me, why are you driving all 4 wheels. It's not going to give you more speed, the fastest commercial model car from some years ago used the standard 2 wheel RC configuration. I still own this car and it was rated at 100MPH out of the box. It was powered by a Nitro engine.

I get some of youre points. Nonetheless i think this could be a really cool concept. Obviously it will be a complicated project but the possibilities are still crazy. Breaking performance will be much better due to having front brakes as well. Also cornering will be better, accalarection will be better, tractioncontrol could be possible. So if done right, i think this could be the most efficient way to deal with it. Also im pretty sure that your 100 mph car is quite a bit bigger than what i have planned. This will be around 1 kg and will have if done right above 2ps. And i think weight will also be negligable. And for tools, i'm in uni so i have lots of tools to make my parts. Now the question is what i can expect from the right motors, do i need gearing, or is there motors that have enough torque to ensure sufficient accaleration. Im not really worried about the top end, more so for the initial start.

The diploma in engineering is being worked on rn

Thanks for the answer.