Robotics

Projects

Rover

• Get bluetooth working
• Check motor mounting angles for faster motor

Ball gun

• Need to get parts list on BrickLink

Clock

• Investigate motor mounting angles

Plotter

• Investigate motor mounting angles
• Investigate pen cradles

Technic

How much to pay by weight? Say 300 parts per kg, 4p per part = 12 GBP per kilo

Per 100 parts (assuming plenty of beams!) = 4 GBP

Subtract postage from what you're willing to pay

Motors

24BYJ-48

About 2GBP each, but slow: 2048 steps per rev and a max of 500 pulses per second is about 4 rev/min, 15 sec/rev

Good page here: http://arduino-info.wikispaces.com/SmallSteppers

4 Phase 5 Wire Connection

• Phase : 4
• Current : 160 mA per winding (320 mA in 4-step mode) Measured: 250mA stopped, 200 mA running fast
• Resistance : 31 Ω per coil winding (from Red wire to any coil)
• Voltage : 5V DC
• Step Angle (8-Step sequence: Internal Motor alone): 5.625° (64 steps per revolution)
• Step Angle (4-Step sequence: Internal Motor alone): 11.25° (32 steps per revolution)
• Gear Reduction ratio: 1 / 64 (Not really exact: probably 63.68395.:1 )
• SO: it takes (64*64 = 4096 steps per output shaft revolution.. In 8-step sequence.
• SO: it takes (32*64 = 2048 steps per output shaft revolution.. In 4-step sequence.
• NOTE: Arduino "Stepper Library" runs in 4-step mode
• No-Load Pull-Out Frequency : 800pps
• No-Load Pull-In Frequency : 500pps
• Pull-In Torque : ≥ 78.4mN.m
• Wiring Instruction : A (Blue), B (Pink), C (Yellow), D (Orange), E (Red, Mid-Point)
• Weight : 30g

Better motors

Stepper Motor: Bipolar, 200 Steps/Rev, 35x28mm, 10V, 500mA

http://proto-pic.co.uk/stepper-motor-bipolar-200-steps-rev-35x28mm-10v-500ma/

This is about 200 rpm, maybe 50 times faster than the 24BYJ-48?

Works well with "Easy Driver": http://proto-pic.co.uk/easydriver-stepper-motor-driver/