Robot GoWest¶
Mecanic work¶
Engines choice¶
This project has to be redesigned, a new engine system will be choosen:
| Steper motor | Brushless motor | DC motor | |
|---|---|---|---|
| Torque | ++ when it's slow | ++ at start and when it's fast | ++ at start |
| Speed | Slow to medium | Fast | Slow to medium |
| Control | Pulses: driver | Voltage: PWM | Voltage: PWM |
| Consumption | + Always | Depending on the speed | Depending on the speed |
| Noise | ++ | - | + |
| Cost | - | + | - |
The actual engine is a DC motor with brushes, the problem is that it is too heavy and there is a huge current consumption when it is starting. We should use another type of motor, for example a stepper motor could be a good compromise between the brushless (sureley the best but the most expensive) and the brush.
We can find stepper motors for about 2€ with the driver.
We will use stepper motors from 3D printers.
Block design¶
The robot will be designed with a "block" approach. The idea is to have the blocks of motors with the reducer, and we could change the entire shape of the robot and keep the same functionalities.
Motors¶
The block "motor" is made up of the stepper motor, the driver and the moto-reducer. The actual version is a reduction of 1/3.
The shape is in MDF: decoupe.svg
You can find how to assembly in the FreeCAD file: Bloc_moteur.FCStd
The parts to 3D print are here: Roue.stl, pignon.stl and support_roulement.stl