Thanks for the input so far. I want to go the route of BLDC as I want to have fairly precise control over the motor speed.
From looking at this video Controlling Gens Ace ESC with Arduino Demo - YouTube, I think I need a setup as per the drawing below.
My goal is to have the motor actually spinning at 1500 RPM. I’ve found a 360kV motor I think will work nicely. If I get a 7.4V Li-Po battery to go with it, it should Theoretically produce 2664 RPM. I think I can then use the Arduino signal to slow down the motor to 1500 RPM instead of 2664 RPM.
I don’t quite understand how the Arduino signal is to regulate how much voltage the motor will see, could someone please explain that for me using the chart above?
For programming, I’ve found the following code ready to use:
m1.write(40); // adjust this number starting from 10 going to 40 until you find out which one will activate your ESC.
m1.write(angle); // Angle needs to be anywhere between 0 & 180, 180 = full speed.
If I have a 360 kV motor with a 7.4V Li-Po battery, an angle of 180 should mean that the motor should be spinning at 2664 RPM right? Someone please verify this is correct.
If this is correct…
180 Angle = 2664 RPM
Then 1 RPM = 0.0675675 Angle (180Angle/2664RPM = 0.0675675 Angle/RPM).
Therefore, to get 1500 RPM I can calculate the angle needed as follows:
1500 RPM x 0.0675675 Angle/RPM = 101.35 Angle
Since the load on the motor is going to lower my speed, this means to get 1500 RPM I will need an angle anywhere between 101.35 & 180.
I’ve selected the following Motor, ESC & Batterys from the links below to get this done.
Electronic Speed Controller (ESC):
I used the following article at the link here to determine how to select everything:
How I selected the motor:
I know I need a low kV rating as all the BLDC motors I can find require at least 7.4V from a LIPO battery. If the kV were too large, the angle needed for 1500 RPM may be so small that the motor may not even turn on. The lowest & cheapest kV I was able to find was the 360 kV BLDC motor. The specs on their website don’t show info for the motor at 7.4V’s, but claims it can run on 2-6 LIPO batteries (2 x LIPO batteries = 7.4V). So I looked at the specs under 11.1V to see that the motor runs to a max Amperage of 7.4A at 11.1V. This means that I want both my battery & my ESC for 7.4A’s or higher.
How I selected the ESC:
I decided to buy the ESC from the same website to keep things convenient for myself. I know I have to get an ESC rated for 7.4A or higher. They had a 10A ESC for $9.99, but for $1 more I could get a 30A ESC so I decided to go with the 30A ESC.
How I selected the LIPO Battery:
I know I want a 7.4V battery that can handle at least 7.4A’s. From the Article, I found out that mAh x C = A. I found a really cheap battery, and used the calculation to find that it had an Amperage of 30 (1200mAh * 25C = 30,000 mA = 30A)
Someone please confirm that this all looks like it makes sense.