How to use CNC in technology lessons
Tunisian children customize racing tricycle
The French government offers French education in many countries worldwide.Lycée Gustave Flaubert in La Marsa, Tunisia, is open for students between 11 and 18 years old. It offers medium school (in French Collège) and high school (in French Lycée), ending with a bachelor exam). All nationalities are welcome, the majority of the children being Tunisians.
One of the subjects that the school offers is Technology, which is a very good way to make children interested in technology at a very young age. The technology classroom includes two desktop CNC machines, and the DeskProto CAM software (the French version).
An annual event at the Lycée is the "Green Machine Challenge": an interclass race with customized tricycles, in which all first years (11 and 12 year old students) compete to become the school's champion. Customization is done in the Technology lessons, by adding a team symbol to the bike.
This Gallery project shows how the Lions team used CAD/CAM to create a great logo for their bike.
Class 6E6 chose a Lion for their team, drawn in 2D.
Each team chose a logo, meant to symbolize strength, power and speed, simply using a Google search. This logo is manufactured and attached to the team's bike.
The Lions used an image found on www.roccat.org. Based on the downloaded image a 2D drawing was created in SolidWorks.
The Lion in 3D: in CAD (SolidWorks) and in CAM (DeskProto).
In SolidWorks it is easy to change the 2D contour into a 3D shape by giving it a thickness. Also the two folds could be easily added.
The geometry (again in flat state) was exported as STL file and then imported in the DeskProto CAM software. in DeskProto it is very easy to generate one toolpath around the outer contour of the 3D geometry. This toolpath then was saved, in a file containing ISO G-codes.
2D toolpaths in the control software (Kay) and on the machine (Isel).
Third step in the process is the CNC milling machine with its control software (most lowcost milling machines use the PC as control panel). The school uses a CPM-3020 milling machine by Isel, with the Kay control software by Galaad.
A sheet of yellow PVC was fixtured on top of a martyr plate (wasteboard), used to prevent damage to the machine's working table. Mount the correct cutter (here a flat tip, diameter 1 mm cutter was used), set the Workpiece Zero Point and GO !
The proud owners of the lion logo.
The two folds in the PVC sheet were made by locally heating the plastic (thermo-folding). Mount the result on the bike, and the "Lions" are ready to race !
A 2D part like this can be manufactured in other ways too, for instance using a laser cutter. Still a system like shown on this page (DeskProto plus a CNC milling machine) is most versatile as it can do both 2D and 3D jobs. Note that creating a toolpath for a 2D part in DeskProto is easier using Vector machining: based on 2D DXF data.