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kaeverens / waterbot

a robot for watering plants
The Unlicense
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increase power to syringe rack #30

Closed kaeverens closed 3 years ago

kaeverens commented 3 years ago

the v2 bot is having trouble opening the syringe because the rack is too far from the centre axis of the syringe's plunger, causing the rack to flex when force is applied, which then causes it to fail to transfer that force to the plunger itself.

the red line shows where the rack should be

image

kaeverens commented 3 years ago

I'm solving the flex problem in v3 by putting the rack much closer to the plunger's central axis

image

I need to adjust the cogs so the power is increased as much as possible when pushing the rack

kaeverens commented 3 years ago

v2 gear ratio calculation.

drive gear (on the stepper) has 16 teeth.

transmission gear has 32 teeth on large cog, 12 on small.

so 1 turn of the stepper is:

  1. 16/32 = 0.5 turns of the transmission gear
  2. 0.5*12 = 6 teeth of the rack are moved when one stepper turn is completed
kaeverens commented 3 years ago

after adjustment, v3 gear calculation is this:

drive gear (on the stepper) has 13 teeth.

transmission gear has 20 and 10 teeth

rack gear has 26 and 10 teeth

so 1 turn of the stepper is:

  1. 13/20 = 0.65 turns of the transmission gear
  2. 0.65*(10/26) = 0.25 turns of the rack gear
  3. 0.25*10 = 2.5 teeth of the rack.

so the transferred force in v3 should be 2.4 times the v2 transferred force.

image