• StickyBot (and SB2) Mechanical
  • Specific Design Pages
  • Design Improvement Thoughts
  • Push-Pull Cable Systems
    • Cables
    • Tubing
    • Length Adjustment

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StickyBot (and SB2) Mechanical

This page contains details, hints, and tips on fabrication processes for StickyBot(s), as well as current design ideas and links to detailed designs.

Specific Design Pages

Here are links to other pages devoted to specific designs

• TwoToeFoot? - A new foot design with two, longer toes, spurs to help with alignment, and cables routed through the ankle to improve compliance.

-- BarrettHeyneman - 27 Jun 2007

• HysteresisReductionInCompliantShoulder? - Design possibilities to reduce the hysteresis in the armlink in order to improve the readings of the stroke sensor.

-- AnnaShedletsky? - 28 Jun 2007

• CompliantWing? - Design to incorporate force sensing in the wing component.

-- AnnaShedletsky? - 06 Jul 2007

Design Improvement Thoughts

Add any ideas for improving the mechanical aspects of the Stickybots here. When you start a specific design solution, move it to its own page and link to it in the Specific Design Pages section.

-- BarrettHeyneman - 27 Jun 2007

Push-Pull Cable Systems

Cables

The current cables on StickyBot and SB2 are unknown, and I can't seem to find any in lab which look to be the same. They seem to be multi stranded (maybe 7x3) and around 0.025" diameter.

-- BarrettHeyneman - 27 Jun 2007

Tubing

We have three types of plastic tubing and various hollow steel needles which can be used to make the cable guides.

Description	ID	OD	Gauge
Black teflon tubing	0.022"	0.042"	24
Black teflon tubing	0.027"	0.047"	22
Translucent teflon tubing	~0.035"	0.065"	?
Yellow PTFE needle	0.034"	0.046"	20
Black steel needle	0.020"	0.028"	22
Light green steel needle	0.023"	0.032"	21
Yellow steel needle	0.0255"	0.0355"	20
Brown steel needle	0.032"	0.042"	19
Pink steel needle	0.038"	0.050"	18
Purple steel needle	0.053"	0.065"	16
Orange steel needle	0.060"	0.072"	15
Dark green steel needle	0.067"	0.083"	14

These hollow needles were bought from McMaster, as was the translucent teflon tubing. The yellow/pink/purple/dark green set of needles telescopes nicely with very little play. The translucent teflon tubing can be stretched around the pink (.050" OD) needles, which is done currently on stickybot.

-- BarrettHeyneman - 27 Jun 2007

Length Adjustment

One way to create adjustable cables (if you want to at all) is to attach a set screw to the end of the cable and "trap" a nut in the part to be actuated (fig 1). Then, by spinning the nut you can effectively increase or decrease the length of the cable. SangBae suggests using JB Weld "steel" epoxy to glue the tubing to the set screw; there isn't enough surface area for superglue to work well. The best method so far is to take a piece of solid piano wire which fits into the set screw's head (for an allan wrench) and a longer piece of steel tubing which the piano wire also fits into (yellow needles are about right) (fig 2) and glue them both to the set screw; with the piano wire extending out of the tube and into the set screw head (fig 3). Then cable can be inserted into the other end of the steel tubing and glued with superglue.

Fig. 1	Fig. 2	Fig. 3

-- BarrettHeyneman - 27 Jun 2007