Stepper motor assembly V22.1

V22.1 (.1 version has more margin between parts)

Render from CAD model

Oil system

The stepper house is filled with sunflower oil. Sunflower oil has lower viscosity and longer expiration date than other super marked oils. Food oil has been used in many previous projects. Other oils was considered but it was either very expensive or an environmental hazard. The main downside with food oil is the expiration date. The oil will turn rancid, smell bad and be sticky and hard to remove. 
Water will get inside the housing if no oil is used, even in shallow water. 
A system for filling oil was made. The design has a syringe house and a vent. Oil can easily be filled inside the syringe when the vent is open. The hole can be covered with the second part of the syringe and a screw cover. The idea behind this design is to make filling easier. Pressing the syringe will also make overpressure inside the stepper house. The overpressure will help keeping the water out. 
Cable is slowly leaking oil into the electronics tube. The cables penetrator is now filled with epoxy. 

...

Magnets and a magnet sensor is used for calibration. The sensor is fixed to the stepper housing. The magnet holder is screwed to the shaft with the same screws for the stepper motor. It houses two magnets with a 90 deg gap between them. TODO: insert angle  The wing is level when the sensor is in the middle between the magnets. Calibration sequence is further explained in the StepperWing library ReadME. TODO: link
Note: Magnet holder must be in correct position (calibrated) when assembling and disassembling the stepper assembly. The magnets is conflicting with the syringe. The port side syringe is broken because of this. 

...