• 3D Model

Info

Added: Jan 25, 2018 11:00
Author: Karel Houba
License: Creative Commons - Attribution - Non-Commercial - Share Alike

Description

This is a demonstration geometrical optics set created by me and my colleague Matej Ryston. It is intended for teachers as a cheaper alternative to commercialy available products. Set requires lot of assembly and other components, but finished result is very easy to use and quite usable. All the instructions are in pdf file.

All is magneticaly held to black or white boards. Laser module is powered by Li-Ion batery, charged by micro-USB and as you can see produces quite visible laser line, simulating propagation of a light ray.

Note: (6.11.2017) - Uploaded working model of Laser Rider.

Print Settings

Printer Brand:

Prusa

Printer:

i3 MK2S

Rafts:

No

Supports:

Doesn't Matter

Resolution:

0,3 mm

Infill:

20%

Notes:

We cannot give you precise instructions for printing as too many settings are dependent on your exact type of 3D-printer and software. Following tips are more based on our general experience, rather than precise instructions. Please take them with a grain of salt and adjust them according to your own experience and equipment.

Material:

The choice of material is more or less up to you, based on your experience. We chose PLA and the print was without problems. Furthermore, PLA is a common and cheap material that is supported by (most likely) 100% of common 3D-printers. The second most common filament, ABS, is not recommended unless your printer is inside a controlled environment that supresses draft and sudden changes in temperature. Otherwise the material might bend, deform or split between the layers, because most of the printed parts are of a comparable size with the printing area of most printers, which makes using ABS more difficult.

Details:

We printed all the parts using a layer height of 0.3 mm. Higher precision for smooth finish is not necessary. If you are using printer settings not based on exact numbers, the appropriate setting should be something like normal, prototype or fast.

Brimm

Brimm around the printed parts is supposed to secure higher stability of less stable components. Our set doesn't contain any, so according to our experience, brimm is not necessary.

Orientation and supports:

The orientation of individual components is in most cases pretty obvious. The print is made in the same orientation as the components will be oriented on the board. Although some components have holes for magnets, supports are not necessary. The only exception is the lid of the laser module.

With the larger components, such as mirrors, we recommend orienting them diagonally, so that they fit on the printing bed more easily.

The bottom part of the laser module is also printable without supports. The only place when they are needed is the battery holder; however, its supports are already part of the model. Any other supports are unnecessary.

When printing the inner parts of the laser module, it is necessary to turn the cylindrical lens holder upside down. In this orientation it should get printed without any supports. With the "cradle" and the "riders", it turns out the keeping the right orientation when printing is important. One might want to print the cradle sideways but that leads to closing of the nail holes. The nail should slide through the cradle freely and be stuck in the riders firmly (some degree of force is required). If your printer prints the holes too tight, it is possible to widen them with a heated nail. If the holes are too wide, some glue at the end of the nail might help.

The top part of the laser module must be printed upside down and is the only one that requires supports, especially the front part of the module. All the other supports (inside holes and letters, air vents) are unwanted products of the support algorithms. Play with the support settings on your software until most of the unwanted supports are not generated (you could for example let the first N layers have forced support). If your software enables creating supports manually, then you are halfway there

Post-Printing

Postprinting process varies wildly depending on the piece you are making. Some parts require only mild filing of edges, some require molding and casting and some require assembly of electronic board.

It all depends on you what modules you want and can make.

Overview and Background

This is a set designed for teachers use only (danger of eye damage). It is a difficult to make but easy to use demonstration set for teaching geometrical optics. If instructions are followed then the resulting set is a very effective and cheap replacement for the commercially availible products.

Set is held magneticaly on the board
Laser module is battery powered and recharged via micro-USB
Light ray is represented with a laser stripe making the ray visible along its path
Set is modular. Meaning the user can make just a part of it and expand on it later

Our intention was to make a set for teaching following topics:

Light reflection
Planar, concave and convex mirrors
Light refraction
Lenses and effect of optical power
Light crossing plane parallel layer
Total internal reflection
Simulation of optical fiber

Lesson Plan and Activity

Print and assemble the set
Introduce the idea of light ray and its propagation through space
Demonstrate law of reflection using planar mirror
Show how reflection happenes on cylindrical mirrors and explain their apllications
Show light refraction on a single layer interface (use parallel plane module)
Show propagation thgrough parallel plane module
Show propagation through lenses of different optical powers
Explain their uses for eye correction
Show total internal reflection on planar module
Show the function of a optical fiber using module from flexable resin

Materials Needed

Short-list

This list is here just to give you a general idea of what you will need. For full list with specifics see pdf instructions.

2 compound transparent resin
neodymium magnets (lots)
reflective foil
Strong laser diode (25-50mW)
Li-ion bateries
additional electronics for the driver circuit

Skills Learned

Optics

Duration of Lesson

2-3 45minute lessons

Files

File name File size
LICENSE.txt 244.00 B
README.txt 5.74 KB
attribution_card.html 2.42 KB
files/Converging_2D_1.0.stl 9.26 KB
files/Plane-parallel_Plate_1.0.stl 3.01 KB
files/Convex_Mirror_1.0.stl 363.46 KB
files/Laser_Rider_1.1.stl 16.49 KB
files/Cylindrical_Lens_1.0.stl 51.16 KB
files/Fork_Holder_1.0.stl 50.28 KB
files/Laser_Top_1.0.stl 315.32 KB
files/Laser_Cradle_1.0.stl 20.39 KB
files/Concave_Mirror_1.0.stl 363.85 KB
files/Diverging_-4D_1.0.stl 13.56 KB
files/Spirit_level_holder_1.0.stl 31.53 KB
files/Spirit_Level_Base_1.0.stl 68.73 KB
files/Instructions_1.0.pdf 1.82 MB
files/Diverging_-2D_1.0.stl 11.21 KB
files/Laser_Base_1.0.stl 498.23 KB
files/Optical_Fiber_1.0.stl 3.01 KB
files/Plannar_mirror_1.0.stl 30.36 KB
files/Prism_1.0.stl 4.38 KB
files/Laser_Lens_Holder_1.0.stl 24.50 KB
files/Converging_4D_1.0.stl 10.82 KB
images/68d6fc8bb97bb153c38ab871c864679b_preview_featured.jpg 44.43 KB
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