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3D Printed Otoscope

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Revision as of 10:34, 4 December 2014 by Amwallis (Talk | Contributions) (Technical Specifications and Assembly Instructions)

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MOST Delta filament as guide.JPG This page was part of an MTU course MSE4777 OA and MSE4777 OB/MSE5777/EE4777/EE5777: Open-source 3-D printing

Please leave comments using the discussion tab. The course runs in the Fall semester. It is not open edit.

3D Printed Otoscope

Project developed by Amwallis
This OSAT has been designed but not yet tested - use at own risk.
This OSAT has been prototyped.

You can help Appropedia by contributing to the next step in this OSAT's status.


  1. An otoscope is simple device used in the diagnosis of ear, nose, and throat diseases. It is essentially a magnification lens with a light and speculum to help open orifices and direct the light. It is commonly used to examine the eardrum, which as the border separating the external ear canal from the middle ear, often has characteristics indicative of various diseases of the middle ear space.
  2. Picture of completed print using

Bill of Materials

Printed Parts:

    1. The main otoscope body weights 20 grams. The approximate cost of this part is $0.50. 87 min
    2. The battery cover weights 6 grams. The approximate cost of this part is $0.15. 19 min
    3. The switch cover weights 2 grams. The approximate cost of this part is $0.05. 4 min
    4. The circular base on which the lens assembly and the ear piece mounts weights 5 grams. The approximate cost of this part is $0.15. 22 min
    5. The ear piece weights 3 grams. The approximate cost of this part is $0.08. 22 min
    6. The lens assembly weights 3 grams. The approximate cost of this part is $0.08. 17 min

Other Parts:

    1. A SMD pushbutton switch is used to activate the otoscope's light. The approximate cost of this part is $0.57.
    2. A white LED is used to shine light into the ear. The approximate cost of this part is $0.80.
    3. A 220 ohm resistor is used to limit current draw. The approximate cost of this part is $0.10.
    4. A 38mm diameter, 150mm focal length concave lens in used. The approximate cost of this part is $3.95.
    5. About half a meter of 22 gauge solid core wire is used. Cost is assumed to be negligible.

Total cost to manufacture is $6.43


    1. The OpenSCAD source files and STLs can be downloaded here: . Additionally the STL files can be downloaded below.
    2. File:OtoscopeBody.stl
    3. File:OtoscopeBatteryCover.stl
    4. File:OtoscopeSwitchCover.stl
    5. File:OtoscopeMountBase.stl
    6. File:OtoscopeLensAssembly.stl
    7. File:OtoscopeSpeculum.stl

Tools needed for fabrication of the OSAT

  1. MOST Delta RepRap or similar RepRap 3-D printer
  2. Depending on print quality, a knife may be needed to shave away plastic on the edges of the parts that come together.
  3. Super glue is needed to join the switch cover and the mount base to the main otoscope body.
  4. A soldering iron and solder is needed to securely attach the electrical components together
  5. Wire strippers and/or diagonals are needed to trim the wiring
  6. Rubber bands may be helpful to hold some of the parts together while the glue dries.

Skills and Knowledge Necessary to Make the OSAT

  1. You will need to know how to solder [1]

Technical Specifications and Assembly Instructions

  1. Provide directions for print/assembly - be detailed enough in your “how to” to ensure that someone could construct the device from your description. Consider the elegance of IKEA like instructions.
  2. Total print time estimate is 152 minutes. Print time estimates for the individual parts are as follows: ratchet - 89 minutes, ratchet cover - 16 minutes, ratchet gear - 43 minutes, and gear pin - 4 minutes.
  3. Assembly time estimate of less than 5 minutes.
  4. Including drawings or pictures of the device at stage of assembly at minimum. (

Common Problems and Solutions

  • A more powerful LED could be used to help direct more light into the patient's ear. Also, many commercial versions have variable light intensity, this could possibly be implemented by using a potentiometer.
  • The speculum is not adjustable, an interchangeable system would be beneficial to accommodate different size orifices.

Cost savings

  1. Assuming PLA plastic costing $0.025 per gram is used ($25 per 1kg spool), the otoscope can be built for $6.43
  2. A inexpensive home use otoscope costs approximately $30.00
  3. This results in a savings of $23.57 as the otoscope can be printed for 21% of the commercial equivalent