Alm Retractor.jpg
Project data
Authors Robert Arden
Completed 2015
Made? Yes
Replicated? No
Cost USD $ 2.32
Export to Open Know How Manifest
Page data
Type Project
Keywords 3D printing, all retractor, surgical tools, plastic
SDGs Sustainable Development Goals SDG03 Good health and well-being
SDG11 Sustainable cities and communities
Authors Robert Arden
Kathy Nativi
Published 2015
License CC BY-SA 3.0
Affiliations MTU
Michigan_Tech's_Open_Sustainability_Technology_Lab
MY4777
Language English (en)
Page views 281


This technology is an OSAT appropriate technology as it will provide a medical tool for others to use that may not have this technology available to them. The parts of this tool are easily printed and the hardware is nowhere near excessive for someone who has a 3D printer. 3DPrint.com has an article about using 3D printed surgical tools in low income countries but only include the most simple retractor. As far as I can tell nobody has made a 3D printed Alm retractor before this.

Bill of Materials[edit | edit source]

STL Files[edit | edit source]

  1. 1x File:Retractor Bolt Handle.stl
  2. 2x File:Retractor Bolt Retainer.stl
  3. 1x File:Retractor Expander Mount.stl
  4. 1x File:Retractor Screw Mount.stl
  5. 2x File:Retractor Arm.stl <-- Need to mirror this part for one arm
  6. 2x File:Retractor Extending Arm.stl

SCAD Files[edit | edit source]

  1. File:Retractor Bolt Handle.scad
  2. File:Retractor Bolt Retainer.scad
  3. File:Retractor Expander Mount.scad
  4. File:Retractor Screw Mount.scad
  5. File:Retractor Arm.scad
  6. File:Retractor Extending Arm.scad

Additional Hardware[edit | edit source]

  1. 2x M3x0.5 10mm screw cost=$0.13
  2. 2x M3x0.5 12mm screw cost=$0.15
  3. 2x M3x0.5 16mm screw cost=$0.16
  4. 1x M8x1 50mm bolt cost=$0.39
  5. 1x M8x1 nut cost=$0.09

Tools needed[edit | edit source]

  1. MOST Delta RepRap or similar RepRap 3-D printer
  2. 2.5mm Allen Wrench
  3. Pliers

Skills and knowledge needed[edit | edit source]

  • Only standard 3D printing skills are needed for this project

Technical Specifications and Assembly Instructions[edit | edit source]

  1. Including drawings or pictures of the device at stage of assembly at minimum. (Upload)

Printing[edit | edit source]

Assembly[edit | edit source]

  • Approximate assembly time is 30 minutes
  • Place small extension arms into large retractor arms
    • Use M3x10mm screws to hold into place
  • Place other end of extension arms into the expander mount
    • Secure arms with the M3x12mm screws
  • Push bolt head into hex pocket on handle
  • Push hex nut into hex pocket on bolt mount
  • Insert bolt through hole in bolt mount and thread into nut until bolt is flush with nut face
    • Take one bolt retainer and hold it flush against the nut face
    • Rotate the bolt by hand until the bolt is through the retainer and about 15 mm of bolt is protruding
  • Attach the retractor arm assembly to the bolt mount
    • Use the two M3x16mm screws to secure the arms, make sure the bolt head sits in the pocket
  • Push expander mount onto bolt and thread last expander mount onto bolt
    • Tighten up the first bolt retainer so that the expander mount cannot twist but the bolt rotates freely
  • Verify range of motion is not inhibited
    • If range of motion is fine then retractor is ready to use

Cost savings[edit | edit source]