CVRA DC-Motor Controller
- CAN interface
- DC motor control with current sensing
- Quadrature encoder interface for motor (5V tolerant)
- Secondary quadrature encoder interface (5V tolerant) (eg. for separate odometry wheels)
- Analog input for RC-servo control
- Runs on 3 or 4 cell LiPo batteries
This project is released under the Creative Commons CC-BY-SA-4.0 license. See http://creativecommons.org/licenses/by-sa/4.0/ for details.
Applying solder paste
- This needs 2 persons.
- Solder paste and stencil need to be cold (couple of minutes in the fridge)
- Use the 3D printed frames. Stick them to the table with double sided tape and stick the PCB to the frame with small pieces of double sided tape. If you don't do this, the PCB will stick to the sencil when you try to remove it.
- To remove the stencil, rotate it around one of the short edges, to pull it as perpendicular as possible with the least amount of shaking.
- Move the PCB with the applied solder paste to a frame without double sided tape before assembling the parts, because they would probably flick off.
- Check the footprints with the smallest pitch under the microscope for bad alignment and if the brim is nice (if it isn't, the paste was probably too warm).
Assembling the parts
- Remove the solder paste on the NC pad of the voltage regulator with the wrong footprint.
- Use the vacuum pump for larger parts and tweezers for smaller ones.
- Preheat the frame made out of plaster to >200°C, else it won't reflow!
- Move the PCB to the plaster frame.
- Put the frame and the thermal probe in the furnace. Take care that you don't accidentally move any parts by touching them with the probe.
- Heat until the solder paste starts to liquidify (shouldn't be more than ~230°C; never go higher than 250°C).
- Keep the peak temperature for about a minute.
- Open the furnace door a little bit to slowly cool down the PCBs.
- Don't remove the PCB from the furnace before it's colder than ~70°C.