Tuesday, October 2, 2018

3D Printing - 'rafting' removal: back to basics

Above: Design as printed.
This is intended as an explanation for the term of 'rafting' that is frequently discussed on this blog.   

This is part of the 'beginners guide to 3D Printing' which is aimed at teachers and students who are printing for the first time or looking at different aspects of 3D Printing.

On the left is a basic 'Unicorn' design.  The design is freely available on Tinkercad, and is public domain.  It is 70mm across, 60mm high and 30mm across.   This is the design as shown straight after printing with all of the 'rafting' still present on the design.  Generally the teacher in the classroom removes the rafting himself, as it at times can be somewhat difficult for students (particularly the younger students) to remove the rafting without damaging the print.   This depends on the print itself and the details of the print, an object that has thin and detailed parts can sometimes require particular attention to remove the rafting.   In the case where the rafting is broken it tends to be repaired with superglue when it is possible. 

The basic tools to remove this rafting that is used by the teacher is a basic pair of pliers with a cutting edge to them.   The second key tool used is a small screwdriver with a 80mm length and a width of 3mm.   This tool is key to removing small amounts of rafting in delicate locations which cannot be generally removed without causing marking or damaging onto the print itself.

The breaking of the rafting around the head of the unicorn and the base of the unicorn.  This has been completed by using the pliers to break the rafting and then wedge out the rafting using the screw driver.

The removal of the rafting is nearly complete.  Particular care has to be taken around the wings of the Unicorn as it the connection between the wing and the body of the Unicorn is only 2mm thick at the place where it joins.  This typically would be an area where we would experience 'breaking' of the print.   The tail can be seen with particular care needed to remove it without it breaking.

The removal of the rafting is now complete.   Despite all due possible care one of the wings of the Unicorn has detached from the print.   At present there is considerable rafting waste from the print which needs to be disposed of.  This is part due to the design, which the head has produced considerable rafting as part of the design, some of the more rectangular objects produced have little or no rafting.   The wing will be attached with superglue prior to printing.

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