Puffin - Trial and error engineering

[Subculture]

Yeah I think it's a typo, he has a 2200mAh in the picture so I'm going to go with that pack. that should give you a continuous current in excess of 10-15A or more, so I reckon your prop/motor combo is probably a bit overcooked if that battery is getting too hot.

What's the motor size, KV, and diameter and pitch of the propeller?

[Occupant]

Type-Ohhh damn... 2200mah

[Subculture]

Okay, so what's the motor size, KV, and diameter and pitch of the propeller?

[Occupant]

D2830, 1000kv, 2” diameter, 3”pitch - 3 blades not the two blade pictured

[Subculture]

That's your problem then. Huge amount of pitch at unloaded speed of 11000RPM+

You want a motor around 300kv-500kv for a prop like that on 3s. It should still be rapid. or consider an inline gearbox of 2:1 or higher. Also consider reducing the pitch of the prop to square or less.

Alternatively, with your existing drive train consider running a much smaller diameter and pitched prop, something around 1.5" diameter and 1-1.25 times pitch.

[Occupant]

Thanks for the info, going to try a different prop first (only changing one part ) simple easy test doing with the 2" just as a oint ot start change the pitch and duration of the blades. pitch of .75 duration of about 130 degrees. while thats printing will look at using the 650kv motor i have in the peristaltic pump in the design se if it fits and if i can quickly just adapt the end cap vs having to do all the parts again. that way if the new prop improves things the slower motor would be another step in the right direction.

should i read by your comment "11000rpm+" that your running full throttle? how does limiting the motor speed via transmitter effect the battery and ESC, concerned the throttling may generate heat in the ESC nd heat up the internal WTC cavity with the battery in it.

[Subculture]

Speed controllers whether brushed or brushless control speed by ‘chopping’ the current using a microcontroller to pulse it on and off. Generally the frequency of the pulses is in the thousands of hertz. With a brushless control the commutation is handled electronically, and handled mechanically with a brushed motor.

The pulsing does create some losses in the system, as transistors take time to switch on and off, and in that time span they have a much higher resistance and therefore generate more heat. However modern transistors are so efficient and fast this is barely a concern.

With the 11000RPM I’m basing that on full throttle. I would say for that motor you want a prop diameter of no more than 1.5”. For a a 2” prop running direct drive, I would look more towards a 35mm outrunner, but you’ll probably be okay with a lower kv 28mm unit. I’d look at running a simple two blade prop.