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STATUS: IN PROGRESS - COMPLETED FIRST REVIEW27 September 2018
By Mike Tan (Interest Group member, miketanct@gmail.com)
After much testing in printing the first design of the Braille Scrabble tile sample, it was found that achieving good consistency in the shape & size of the Braille dots was quite impossible, especially when printing with different printers. The lesson learnt is that the quality of fine details present on the top layers of an FDM print is sensitive to printer performance, filament quality and slicer settings. So it was decided that the print orientation should be changed to have the dots facing sideways instead of upwards so that the dots can be reproduced distinctly & consistently (just like when printing a Lithophane).
This change was tested on different printers (Flashforge Dreamer, Prusa i3 Mk2, Creality CR-10 and Ultimaker 2+) and all produced the same dot shape and size. Thus, it was decided that the tile should be redesigned optimally for this orientation of printing.
The depth of the tile was made thicker to provide better bed adhesion and an inset was also incorporated at the back of the tile for easy tactile identification of the tile’s front-back facing. The inset also reduces printing time and allows for additional information to be printed at the back of the tile without interfering with the placement of the tile on its back.
The design of the board was also simplified by removing the notches that were originally made to facilitate picking up the tiles from the board. As the tiles have been made thicker, these notches are no longer necessary. With the notches removed, printing time is shorter due to less retractions and chances of print failure is also reduced due to simplification of the design.
The first attempt to fit the 4 quadrants of the Scrabble board onto the ring mount was unsuccessful. Only 2 quadrants were able to fit in at a time. It seemed that the gap allowance designed to cater for the Ultimaker’s printing inaccuracy was not sufficient. So the ring was modified to have both the inner & outer diameters adjusted for a more narrower ring, after which all 4 quadrants of the board were able to fit.
The first meeting to review all the printed parts of the Braille Scrabble Project was held at iC2’s office on 18th Sep 2018.
iC2 was satisfied with the design and only had a minor concern regarding the printed line texture of one of the tiles being a little coarse, which might interfere the users’ ability to feel the dots. As that tile was printed at 0.2mm layer height, assurance was given to them that the final tiles would not be that coarse when printed at the finest resolution of 0.1mm layer height.
One complete set of tiles will have to be printed so that iC2 can test out the Braille Scrabble with their students.
28 July 2018
By Mike Tan (Interest Group member, miketanct@gmail.com)
This project is an initiative by NLB Orchard to use 3D printing as a tool to create customised products for use by the visually impaired in the community thru a collaboration with iC2 Prephouse (https://ic2.com.sg/). The first product for the project a version of the popular Scrabble board game that will be suited for play by the visually impaired.
Addi(c)tive Builders, the 3D printing interest group at the Tampines library PIXEL lab was contacted to help out with this project in June 2018. We have since designed the Scrabble Tile Holder and the Scrabble Board. The Scrabble tile has already been designed by a previous volunteer in NLB Orchard and is pending review by iC2. It features the Braille alphabet system. Some photos of the design and test prints are shown below.
Design of Scrabble Tile Holder (by Alvin Chang)
Design of the Scrabble Board (by Mike Tan)
Board is split into 4 quadrants to fit the maximum printable size of the 3D printer at NLB Orchard.
Test printed a small section of the Scrabble board and the board assembly ring mount (shown in the background).
Fitting of the printed test parts.
Printed tile holders.
A sample print of the Braille tile designed by a previous volunteer at NLB Orchard. Shown in the background is the normal Scrabble tile.
A section of the Scrabble board being printed on the Ultimaker 2+, the 3D printer that NLB Orchard library purchased when they reopened at Orchard Gateway in 2014. The cooling fan ducts have been recently replaced with an enhanced version (3D printed in white PLA) to improve the part cooling performance after it was found that the stock ducts were not efficient and contributed to poor print quality.
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