A50S

Description

The A50S was designed specifically for use in Beatleweight and Featherweight combat robots. It runs the extremely popular VESC®*-Project firmware. We use it for drive on our FW Elevate and weapon/drive on our BW Uplift.

Our biggest problem with the BLHeli_32 ESCs that are very popular for BW weapons, is the lack of a sensible programming interface. So we have a standard microUSB connector for connection to a PC for tuning with VESC®* Tool.

Additionally by using VESC® firmware they have excellent current control so you are less likely to melt your motors!

A key feature required for robot use is HFI (High Frequency Injection) which after tuning allows the ESC to know exactly what the position of the motor is at all times. This means the maximum torque can be obtained even without the use of sensors. Its a bit like having a virtual encoder attached to the motor.

The A50S can be used for both Brushed and Brushless motors.

Quick tips on setup

Max battery cable length without additional capacitors is 30cm

!!ONLY USE 1 BEC, cut the 5v wire on all but one or the BEC can be damaged!!

Please be careful when programming settings.

We recommend detecting motors using the FOC motor setup wizard. This will automatically find the correct settings for your motor.

LiPo batteries are extremely dangerous if handled incorrectly.

ALWAYS run with a fuse.

Current Handling

23A continuous with no additional cooling

35A continuous with light airflow

50A burst

Mechanical Features

Dimensions: 34.2 x 17.9 x 5.5mm without wires
Weight ~19g including wires and heatshrink
Battery/Motor cable length: 10cm

Electrical Connections

16 AWG silicone motor and battery cables
26 AWG silicone PPM/Servo connector
Integrated 0.4A 5V BEC

Motor Commutation Modes

FOC - Sensorless, HFI
BLDC - Sensorless
DC - For driving brushed DC motors on outputs A and C.

Motor Control Modes

Current - Controls current to motor irrespective of duty cycle
Duty Cycle - Controls duty cycle sent to motor irrespective of current
PID RPM control - Controls motor RPM using a PID loop, gives high torque even at low rpm.

Control Interfaces

PPM

Voltage Rating

4-27v, 2-6S LiPo

Safety Features

Active current limiting - actively limits motor current to stay below programmed limit
Software over current protection - stops motor running if the current exceeds programmed limit
Slow temperature cutoff - ramps down motor current when approaching programmed max temperature
Battery voltage cutoff - ramps down motor current when approaching programmed voltage cutoff
Under / Over Voltage cutoff - stops motor running if the voltage goes outside the programmed range

Programming features - using VESC®* Tool

Adjustable current limits, Battery and Motor current are independently controlled
Adjustable voltage limits
Adjustable RPM limits
Adjustable Power limits
Adjustable duty cycle limits
Adjustable regenerative braking
Adjustable throttle curves and ramping time
Real time and Sampled Data monitoring and graphing
Automatic motor detection and tuning
HFI turning

Motors tested and tuned to work, (Config files available here https://drive.google.com/drive/u/0/folders/1md26k83i8Agh_BcT1hI3vRV4ectFP86r)

1806 - 2300kv (OPBox motor)
TP2040 - 3Y 6050kv
SK3 4250
NTM4248 - 650kv
5065

The A50S runs the popular VESC®*-Project firmware by Benjamin Vedder.

* VESC is a registered TM, owned by Benjamin Vedder

Brushed/Brushless configuration and performance

Posted by Isaak A Malers on 2nd Dec 2020

Brushed:
- One of the things I like the most about the A50S is its ability to drive DC motors above their voltage rating safely. In Brushed mode, with a duty cycle limit of 65% and a current limit of 1.8amps per motor, I am able to run Silver Sparks (Mabuchi 050) motors on 24 volts. Connecting them directly to a 24 volt source would destroy the motor extremely quickly. This opens up a LOT of options for beetles, that previously were difficult because you pretty much had to run 3s or 4s batteries to avoid destroying drive motors. The A50S is my favorite brushed drive solution for 3lbs, and even 12lbs robots for this reason.

Brushless:
- As far as brushless performance goes, the A50s has a lot of options available for tuning that no other product can match. By setting current controls and using FOC mode, you can control how much heat gets put into a motor and ensure nothing burns up. The high voltage capacity and current limiting enables some interesting design choices. I'm able to run a "3s max, 25 amp max" motor on 6s, with a 17 amp current limit in the A50s. This solution runs cooler, pushes more power, and with a gear ratio adjustment has the same top speed. The result is a huge spin-up improvement, with a system that runs stone cold. I've also tested a Prop drive 5050 on the A50S, with a 55 amp current limit. Predictably, the system overheated. However: the A50s gracefully protected itself by providing less and less current as it got too hot. I wanted to see how big of a motor I could get good performance out of. Its possible to get 10x the rated amperage through some of the bigger vescs for very short bursts, enabling a Fesc6.6 to power a 300amp stall motor. For the A50s I was seeing 55 amp short term bursts before the A50s started to really struggle with delivering more current, and the motor performance suffered. Overall: for brushless motors the A50S is a compelling choice for beetles that want to push a lot of volts instead of a lot of current. It enables designs using a 1200w motor at 6s, which is much more manageable than a 1200w motor at 3s.

2 Reviews Hide Reviews Show Reviews

5
ESC Performance

Posted by josue on 18th Dec 2020

These ESC are great, I use the option speed control to drive the motor. I t was necessary to put a small capacitor in order to drive my motor. I would be helpful to have only one ESC to control 2 motors, looking for simplicity and for reducing weight.
5
Brushed/Brushless configuration and performance

Posted by Isaak A Malers on 2nd Dec 2020

Brushed:
- One of the things I like the most about the A50S is its ability to drive DC motors above their voltage rating safely. In Brushed mode, with a duty cycle limit of 65% and a current limit of 1.8amps per motor, I am able to run Silver Sparks (Mabuchi 050) motors on 24 volts. Connecting them directly to a 24 volt source would destroy the motor extremely quickly. This opens up a LOT of options for beetles, that previously were difficult because you pretty much had to run 3s or 4s batteries to avoid destroying drive motors. The A50S is my favorite brushed drive solution for 3lbs, and even 12lbs robots for this reason.

Brushless:
- As far as brushless performance goes, the A50s has a lot of options available for tuning that no other product can match. By setting current controls and using FOC mode, you can control how much heat gets put into a motor and ensure nothing burns up. The high voltage capacity and current limiting enables some interesting design choices. I'm able to run a "3s max, 25 amp max" motor on 6s, with a 17 amp current limit in the A50s. This solution runs cooler, pushes more power, and with a gear ratio adjustment has the same top speed. The result is a huge spin-up improvement, with a system that runs stone cold. I've also tested a Prop drive 5050 on the A50S, with a 55 amp current limit. Predictably, the system overheated. However: the A50s gracefully protected itself by providing less and less current as it got too hot. I wanted to see how big of a motor I could get good performance out of. Its possible to get 10x the rated amperage through some of the bigger vescs for very short bursts, enabling a Fesc6.6 to power a 300amp stall motor. For the A50s I was seeing 55 amp short term bursts before the A50s started to really struggle with delivering more current, and the motor performance suffered. Overall: for brushless motors the A50S is a compelling choice for beetles that want to push a lot of volts instead of a lot of current. It enables designs using a 1200w motor at 6s, which is much more manageable than a 1200w motor at 3s.