Step 2: Holes & Blends

Add channel holes

  • Now, we build the holes into the cylinders to get our channels (Insert → Design Feature → Hole).
  • Zoom in on one channel as shown in the image below and choose the edge of the extruded cylinder.
  • The edge should be highlighted in yellow.
cda-step2-1.png

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  • Now enter the data for the channel.
  • Set the “Diameter” to 7mm, the “Depth” to 50 mm and the “Tip Angle” to 150°.
  • Finalize by clicking “OK”.
  • Repeat this process for the left channel.
  • The middle channel uses the same procedure, but with a diameter of  3 mm.
cda-step2-2.png

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  • To check whether your channels penetrate into the combustion chamber or not, use “Crtl+H” to open the “View Section”.
  • Choose the YC-orientation and click “OK”.
  • Now, your actuator should look like the figure below. If so,  exit the “View Section” (View → Section → Clip Work Section)

 

cda-step2-3.png

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Add edge blends

  • Now, we add edge blends in order to smooth the surface.
  • This is important, since the silicone has a higher chance to tear where there is an incisive angle.
cda-step2-4.png

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  • Insert a blend (Insert → Detail Feature → Edge Blend).
  • Choose edge separating the horizontal cylinder from the combustion chamber.
  • Choose a radius of 10 mm.
  • Finalize by clicking “OK”.
cda-step2-8.png

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  • Select the two edges shown below and use a radius of 2 mm.
cda-step2-5.png

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  • Select the edges shown below and use a radius of 1 mm.
cda-step2-6.png

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  • The edges shown below should also have a radius of 2 mm. 
  • Finalize again by clicking “OK”. You now have designed your combustion driven actuator.
cda-step2-7.png

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Bibliography

Loepfe et al. (2015) Contrast Agent Incorporation into Silicone Enables Real‐Time Flow‐Structure Analysis of Mammalian Vein‐Inspired Soft Pumps.

Loepfe et al. (2015) An Untethered, Jumping Roly-Poly Soft Robot Driven by Combustion.

Loepfe et al. (2014) Design, Performance and Reinforcement of Bearing-Free Soft Silicone Combustion-Driven Pumps.

Schumacher et al. (2014) 3D printed lost-wax casted soft silicone monoblocks enable heart-inspired pumping by internal combustion.

Shepard et al. (2013) Using Explosions to Power a Soft Robot.

Stergiopulos et al. (2014) A Soft Combustion-Driven Pump For Soft Robots.

Contributors

Michael Loepfe