More!

.gitignore

+.*
+# Vim backups
+*~
+# Eagle library backups
+*.l#?
+# FreeCad backups
+*.fcstd1
+# Rendered STP files
+*.step

NotesAndCalculations.txt

+Rough force numbers:
+- 50-100N maximum pitch force
+  - Approx 5-10kgf
+  - That's more than a 3l jug of milk, but it is linear....
+  - Can reduce max force and just cap out earlier.
+- DIMENSIONS:
+  - Yoke body is ~45cm wide
+  - Pitch arm is around half of the middle distance to the pivot (10cm)
+- 10cm arm with force of 50N is 5Nm
+- 20-1 reduction gear to provide 5Nm from a 0.25Nm stepper
+
+Desired force:
+- Heavy planes require at least 0.074 daN/kt (0.74N/kt) stick force gradient
+  > At a speed of 300kts, this is 22.2 daN (222N, 22.6kgF)
+  > That's a pretty damn heavy pull, even at 300kts. What deflection is this for?
+  > Assume max possible deflection
+- Motor torque requirements depend on the gearing and span of the yoke shaft.
+
+Use a stepper motor to provide feedback
+- https://www.altronics.com.au/p/j0070-42-step-stepper-motor-and-lead/
+- 5mm shaft
+- Minimum gear size is around 10mm wide, with 1mm deep teeth?
+- Count of 10?
+- Need 200 on the target gear
+- using the same tooth size of `3.14mm` per tooth gives an approx diameter of 200mm
+- Tge stepper as 1.8 degree steps (42 steps), using a 20-1 reduction a single
+  step will be 0.09 degrees (which at 10cm is a very small amount, approx
+  0.1mm)
+
+
+
+Arm length is ~10cm at idle, this arm can move across a +-10cm travel
+- Max extension, the arm will be at 45 degrees, and 14.1cm long
+- The arm's movement range is +-45 degrees
+- Main limiting factor is the travel of whatever gear is put on the arm, it
+  has to avoid the brace for the sensor.
+  - Can either use a small gear (so it fits, with no limit to travel angle),
+  - OR use a large partial one (with a limit to the angles involved)
+- The smaller gear will probably require two layers to get sufficient torque
+- A larger gear may not have the required level of travel...
+  - BUT, it could be hollowed out!
+  - Limited space still
+
+TODO: GET FUCKING MEASUREMENTS YOU FUCKING MORON
+
+
+- Measurement arm:
+ - Axis circuluar: 27mm
+ - Inner raised portion: 19.5mm round, 6.5 off floor
+ - Spars: 2.2mm deep, 1.3mm thick
+ - Minimum arm length: 7cm 
+ - Travel: +-5cm total
+ - [CALC] 8.6cm max arm length
+ - [CALC] +-35 degrees
+- Space around arm axle.
+ - Around 24mm
+- Screw pillar height: 48mm
+  - So, around 90mm of space vertically (from floor to ceiling)
+- Screw pillar: ~55mm from middle of arm
+
+
+
+The larger of the hobby motors at altronics: https://www.altronics.com.au/p/j0026-F260-4.5V-hobby-motor/ can run at 8400rpm max efficiency
+- Assuming a target speed of 60rpm (1rps) at the arm
+  - This can move to full extension in 100ms
+- 140 times reduction to meet target speed
+- Torque is 2.16m Nm at max efficiency
+- This gives 0.3 Nm of torque after reduction.
+- At maximum arm extension, this is: 3.5N (4.3N at rest)
+- When stalled, the motor can give out 13mNm of torque, which would be 21N at
+  max extension
+
+
+See https://engineerdog.com/2017/01/07/a-practical-guide-to-fdm-3d-printing-gears/
+
+The above numbers seem reasonable for a first pass.
+- Now need to design a 140x reduction gear arrangement.
+- 7x20? 10x14? 5x4x7 (small ratios are usually a good idea)
+  - Recommended minimum size is 13 teeth (with 20 degree pressure angle)
+  - May need four pairs, this is getting crazy.
+- SPACE: On the first large gear: 24mm radius (48mm diameter)
+  - Might be able to fit a 52 tooth gear (2.5 pitch, 20 pressure, 20mm hole) in the available space.
+  - Rough measurment is 44mm outer diameter, will fit.
+
+52 teeth = 44mm
+91 teeth = 86mm (huuuge)
+
+
+Using a stepper could work instead
+- a https://www.altronics.com.au/p/j0070-42-step-stepper-motor-and-lead/
+  stepper can do 0.23Nm of torque (stall)
+- Multiply this by 8 using two gears (which will fit) to get 2.2kgF
+
+Problems with stepper:
+- More complex control logic
+- Slower response (motor can maybe do 600rpm at absolute max)
+  - 1.25 rps, 80ms travel time.
+  - Actually, not that much slower!
+
+MOUNTING:
+- Steper has mounting holes, can just screw it onto something.
+- Design up a bracket? Needs to be able to hold the flying gear between the arm and the motor.
+  - Bracket to hold the gears in place when yoke is upright
+  - Another bracket on the other side to hold the motor in position (needs some way of holding itself in place.
+
+
+
+
+
+25mm from axle to RHS edge
+20mm from axle to LHS edge
+55mm from axle to far
+