Design, lasercut, and document a parametric press-fit construction kit, accounting for the lasercutter kerf, wich can be assembled in multiple ways
In my first attempt (and until now the only one) I used Fusion 360 to make my design and I started with a simple piece. In addition, for the type C socket I used 2.95 mm (ie - 0.05 mm considering that the thickness of the MDF sheet is 3mm). Although, according to the tests I did in group work, I had a good fit when I used a width of 2.96 (-0.04 mm) I wanted to make sure that the lace was strong.
So for desing in Fusion 360, I began to sketch the idea in 2d desing, for this I use the change parameters option for create a parameter list, acording to the kerf reference, the use extrude for 3d the sketch.
So, I design a square with c joint, in diferent sizes and circles.
3d Fusion 360 file
In addition, I wanted to make the model in 3D to see what was left, however, I found the problem that when I managed to duplicate a piece, I could not make the parameter is also copied, so I gave up to continue the parameterization. Another problem I had was that I drew some curved lines, but when exporting to DXF format and opening the drawing in Corel Draw to print the pieces, I did not recognize the curved lines, so I left straight lines only. The final design should look like this.
The picture represents the final asemble model.
Although 3D design was not useful for laser cutting, just to visualize the final result. I went back to designing the pieces, but now only in 2D with the intention of making a first attempt to cut and assemble. I can not do the smoothing to the edges (chamfer) since I did not find the option to do it in 2D, only in 3D.
Finally I sent the drawing from Fusion 360 to Corel Draw in DXF format using the Autodesk A360 web service.
About the laser cutting software
Trotec Job Control is the default software for control the laser cutter. Once you have the design in DXF file open in a program such as Corel Draw, is possible to send the job through print command. After defining the framework of the design in the print options of Corel Draw, select the Job Control option for access to the software. The basic way for send to cut from the Job Control needs only define the basic parameters (power, velocity, and frequency), and usually define a line color for differentiating engrave and cut, then only send to the machine.
Material: I use the 3 mm MDF again
Security recomendations before cutting
- Never take your eyes off the machine, there is a risk of fire
- Use lenses with UV filter or better avoid looking directly at the laser, it damages your eyesight.
- Close the lid and turn on the air extractor, toxic gases and particulate material can be generated.
As I made a first trial cut, I decided not to cut all the pieces so as not to waste material, however, it was the only cut I made. The "C" fitting of 2.95 mm (or -0.05 mm) turned out to be too tight, which makes the pieces difficult to handle. On the other hand, for the "u" type lace I used a kerf of (+/- 0.02) however it also turned out to be very tight and difficult to manipulate, even when I tried to separate the pieces, I ended up breaking them in lace.