Bee Feed Syrup Pump - Proof of Concept
This construction manual for a feed syrup pump shows the first experimental setup to test the functionality of an impeller pump with stepper motor drive.
Materialliste
Description
Operating an impeller pump with a stepper motor was based on the idea that the feed syrup pump should be mobile and cost no more than €1,500. A speed control for regulating the flow rate was desirable. These criteria ruled out the use of a three-phase motor and led to the following experimental setup.
Assembly instructions
The impeller pump is mechanically connected to the stepper motor via a coupling.
In my first test setup, I used a Nema 34 12 nm closed-loop hybrid servo motor with a driver. In retrospect, this turned out to be less than ideal for two reasons. A closed-loop servo motor shuts down as soon as it 'loses' a step, which can happen quickly under heavy loads. The second disadvantage of this motor is that it requires at least a 110 V supply voltage to achieve the required torque. Therefore, two 60 V power supplies connected in series are necessary.
A closed-loop stepper motor typically has two cables: a 4-pin motor cable (A+, A-, B+, B-) and a 6-pin encoder cable. The encoder cable is connected to the encoder input of the closed-loop motor driver. The 4-pin motor cable is connected to the driver's high-voltage inputs of the same name.
The two 60 V power supplies are connected in series and connected to the high-voltage AC input of the motor driver.
The PWM generator requires the 24 V supply voltage of the 24 V switching power supply. The control signals (PUL+, PUL-, DIR+, DIR-, ENA+, ENA-) are connected one-to-one to the control signal inputs of the motor driver.