Best Practices for Robot Design

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Best Practicesfor Robot Design

• FIRST Kickoff
• Novi, MI
• 4 January, 2003

Artur Ostrowski Artur7123_at_yahoo.com
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Consider alternate aluminum profiles
Angle 1x1 1/8 thick
Square 1x1 1/16 thick Same weight, much
more strength and stiffness
The possibilities are limitless
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Modular Extrusions
Boschframing.com Alu-flex.com Faztek.net
Team 342
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Be careful with welds
Weld easy to break (force causes tension)
Reinforcement
Stronger weld (force causes shearing)
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Be careful with concentrated forces
A thin wall is easy to tear.
Reinforcement makes the wall harder to tear.
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Torque transfer

• Splines very strong, but very hard to make

• Key-way strong, hard to make, but components
  with key-ways can be ordered

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Torque transfer cont.

• Frictional devices i.e. trantorque, fairloc
  strong, easy to use, requires larger diameter hubs

Fairloc
Trantorque
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Torque transfer cont.

• Dutch pin strong, very hard to make if shaft and
  hub are different hardnesses

• Through-pins moderate, easy to make, requires
  larger diameter shaft for the same strength

• Set screw moderate (if used properly two per
  joint, flats on the shaft, Loctite)
• Welding very strong for proper materials (low
  carbon steel), permanent

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It is easier to make a good rotational joint
than a sliding joint
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Sliding joint ratio
WIDTH
LENGTH
LENGTH
2
WIDTH
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Guidelines for arms

• Slow moving
• Rigid
• Light (the farther from pivot the lighter)
• Driven by electric motor if the arm must stop in
  any position
• Driven by pneumatics if stops are required only
  in the extreme positions
• Potentiometers on all pivots
• Potentiometers remotely mounted to allow for
  adjustment of motion to full travel of
  potentiometer

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Object Pick-up
Multiple objects Continuous action Rollers Co
nveyer (smooth or with shelves) Brushes Self-adju
sts to the size of the objects or powerful enough
to squeeze the largest object down to the size of
the smallest
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TEAM 9520 balls in 5 sec