assignment

Group Assignment
- Characterize your lasercutter, making test parts(s) that vary cutting settings and dimensions

Individual Assignment
1- Cut something on the vinyl cutter.
2- Design, lasercut and document a parametric press-fit construction kit, accounting for the lasercutter kerf, which can be assembled in multiple ways.

Software Used

SketchUp,Fusion 360, RD Works V6, AutoCAD, Adobe Illustrator, Google Chrome, Sublime Text, Photoshop, Git
         

Files used:

Pressfit Palm .SKP                             Download
Palm individual pieces .SKP             Download
Fab lab logo .DWG                            Download
Palm Fusion File .F3D                       Download
Parametric trunk .F3D                      Download
Fab Lab Stickers .S3D                       Download

Walkthrough

File Preparation
SketchUp



Model 1 - I considered the press-fit assignment and began testing different shapes and ideas.





I decided upon a modified version of a donut without the interior shell yet structurally sound.





Stacked the right way, the design can have a stem and leaves branch off the trunk by an additional, almost vertical slot.









Model 2 - I used Fusion360 to create the circular trunk so that I could make "trees" of various sizes. Rather than make individual trunks one by one, I designed the model with parameters so that I could modify it easily. I used tutorials to guide me through drawing lines in the sketch space.

By clicking Modify/ Change Parameters, a menu pops up to add parameters.

I accessed the workspace by installing the streaming software for Fusion 360. I created a new sketch in Fusion 360, paying close attention to measurements and cut alignment.

I sketched a square with 3mm width and 3mm height on the perimeter of a circle

Next I repeated the shape around the circle

I used the extrude command to make the sketch a solid 3mm wide

This created a body with the thickness that I specified (3mm)

I created a parameter for the thickness and called it 'material'. Then I clicked on the geometry for the extruded distance and replaced it with 'material'.

Here I tested changing the value of 'material' to 10mm instead of 3.

I set a parameter for the interior circle to be able to adjust the width of the ring


For this parameter I linked it to the width of the pressfit groove. This would be useful whenever I wanted to cut this out of a thicker material.


I created a parameter for the number of pressfit grooves called 'repeat'. Here I adjusted from 25 to 14 grooves.

Laser Cutting

Now that I had a file ready to cut, I could relearn what an incredible piece of equipment the laser cutter is. We started the class off with a little bit of troubleshooting:

Group Assignment

Machine operation and size Laser size - 100W tube Bed size - 120cm x 90cm

Cut material properties Thickness: 0.5mm - 7mm Materials: Wood, Paper, MDF, Acrylic

Interface Reads .DXF, .AI, .JPG, .BMP files Uses RDWorks v6 to edit and send to print

Placing files - Check the bed before use - Make sure material lays flat

Watch for falling objects - Never leave the machine while it is operating - Listen and check machine operation frequently

Calibrate and service often Align and clean all three mirros and the focal lens Change water in the chiller twice per month

The laser cutter at the shop cuts 3mm acrylic at settings of speed 14 and power 40.
It can cut through 4.5mm acrylic at settings of speed 8 and power 70.

The machine parameters I used to cut through the 3mm compressed cardboard were
speed 12
power 40




This is a view of what the machine looks like while it is operating. In the video you can see that smoke and bright light is created. It is VERY IMPORTANT to not look directly into the light of the laser as it can cause permanent damage to your vision.

The smoke that is created must be extracted with the use of an extractor fan and accordion hosing leading to a vent on the outside of the building.


Pressfit Palm








Parametric Module

Vinyl Cutting

In addition to the laser cutter, this week I used the vinyl cutter to make some stickers for our glass doors.




The vinyl cutter is another type of computer-controlled machine that moves a tool on the xy plane. In this case, the computer controls the movement of a sharp blade over the surface of the material and performs a 2d cut. Rather than use a beam, the Vinyl Cutter uses an adjustable blade.




Our teacher showed us how the machine works, there is a horizontal bar that rolls the vinyl in and out.


The software used for running the lab's vinyl cutter is called Sillhouette. In the user interface you can assign print properties to different paper and vinyls, to accurately cut vector images into vinyl and paper material. I chose to cut a logo out of vinyl that could be transferred onto glass since our lab didn't have one.

Using illustrator I traced over an image of our logo and exported a .dxf file.

I opened the .dxf file in Silhouette (PDF and AI were unrecognizbale formats).

I selected the vector lines and modified them to the size of my material 12".

I copy, pasted and arranged several of the logos since I wanted many stickers.

I clicked on send in the top right corner to assign values to the line before printing.

I added cuts to the interior lines, cut edge to the perimeter and set the depth to 3 in the program.

I adjusted the depth of the blade to the recommended cut depth (for this cutter 3) as specified for the material being used. This was easy to do, by removing the black pin and rotating it in the plastic hole below it.

I cut out several logos and practiced transfering the logo from the paper.



I used masking tape that is 5" wide to remove the vinyl sticker from the paper. I laid the vinyl flat on the table and using my fingernail, I rubbed the masking tape on the color side of the vinyl. When I pulled the tape off, it removed the vinyl and let me transfer the sticky, underside of the vinyl to the glass.




Depending on the position you want the vinyl to face, make sure to take into consideration whether or not you need to mirror image the vinyl. For example, you could place something on the inside of a glass display so that it couldn't easily be scraped off.

This type of cutting was new to me and I was very impressed at how precise the razor blade was able to cut, even in circular patterns. In some applications, one of the benefits of using a vinyl cutter over a laser is that you could get sharp edges without having to do any finishing. On the laser you would get burnt edges and even discoloration of inks. With a Vinyl Cutter you get clean crisp and sharp edges.

Once cut, the vinyl peels easily

It can then be transfered onto a surface

Note: be aware of the direction you want the vinyl to be facing, outside facing in or inside facing out (in the latter be sure to mirror your image).

Conclusion

I was happy with our group assignment because it helped me learn more about the laser in the shop and how to properly use it. This machine is always in use by students from a local architecture school and a lot of people depend on it to complete their projects.

I was also happy to learn about the different software that can be used to create precise files that a computer can read and manufacture.

In Fusion 360 I learned more about Parametric models and designed and built an adjustable tree trunk. It was a desktop item but if I wanted to scale up I could make it as tall as the room simply by adjusting the parameters I biult into the model.

For cutting thinner materials I was happy to learn how to use the vinyl cutter. The software was free online and easy to use and I was making my own stickers in less than an hour.