Laser Cutting: glamourized an unloved old tshirt

Here at FabLab@SP, the techno arsenal's capacity  is increased over the last few months. One such is the count of laser cutter now sitting working busily on the production floor.
Laser cutter has been the workhorse for any given FabLab/TechShop; it cuts precisely on a variety of material ranging from wood to fabric. It is music to the ears for people like me that can hardly cut a straight line using a pair of scissors or a pen knife.

Initially, there is only one laser cutter, the HAS system. Yours truly has been well acquainted with laser cutters from manufacturers such as epilog, and universal; but the HAS system is definitely a first timer. The quirky-ness of the HAS system warrant a blog post for itself. So how quirky is quirky? The software interface is in "deutch"; not only that, yours truly failed to "google" for the specs of this system given the identification marking found on the surface of this system. Then comes the rayjet, a "mobile" desktop size (having said desktop, it comes with it's own wheelie) laser cutter; smaller bed size is traded off for mobility. Last week, finally the epilog laser cutter is awaiting to be commissioned into the production floor. Having the laser cutter itself is not sufficient without the proper fume extraction kit. Having said kit, it stands as tall as 3 mini bar fridges stacking on top of each other.

This post is not much of an SOP on how to operate a laser cutter, but rather what to make with the laser cutter. The lasses (the laser cutting girls: shar, eugenia, lei) whom intern at FabLab@SP has found good use of the laser cutter by glamourizing an old tshirt in their "free" time. The process describe below is generic for laser cutting of old tshirt on any variety of laser cutter.

Parts needed
1. old tshirt
2. digital design (e.g leopard print)
3. access to laser cutter

Work flow
Prep the old tshirt
1. find a piece of board that is 3mm thick wood/acrylic with sufficiently large surface that is lying around in the FabLab@SP; the surface area is relative to the size of the tshirt to be cut
2. insert the "board" into the tshirt, identify and measure the area to be laser cut
3. stretch the tshirt and then secure the edges with some paper clips/scotch tape

Prep the digital design
Note: digital fabrication with laser cutter, the software that is used to draw the cutting line must be 0.01mm or "hairline" thick, in "black" colour to cut on the HAS (but in "red" on the rayjet and universal). Pre-processing a picture file to be laser cut is a must!
1. Choose drawing software of choice, e.g adobe illustrator, inkscape, librecad, etc.
2. Open a picture/design/pattern of choice. In this example, eugenia has downloaded wild life pictures of leopard rosette pattern.
3. create another "layer" on top of the "picture with leopard rosette pattern", and then trace the outline of the rosette with black lines configured accordingly to the above mentioned requirements.
3a. Eugenia found a way to reduce the time needed to trace the rosette. I shall not spill the beans but you can observe from the file uploaded.
4. delete the underlying picture file and export it to a format that is friendly to vector drawing software (e.g coreldraw)
5. the resulting file from this process ready to be laser cut is available here https://www.dropbox.com/s/704scb3g6gwvg9d/leopard%20prints.ai

Prep the laser cutter for cutting
0. align the tshirt to the bed of the laser cutter with the cutting surface facing up
1. calibrate the height of the Z-axis. This calibration process differs between the laser cutter manufacturers. Time to RTFM!
2. import the digital design into the vector drawing software (eg CorelDraw)
3. commence SOP of laser cutting; setting used to laser cut on cotton fabric is 25% power, 100% speed; the setting might differ from laser cutter to laser cutter.
4. examine the end result

What is a post worth without pictures?

Prep the tshirt and align on the bed of laser cutter

Preparing digital design to be laser cut on coreldraw

laser cutting of the digital design in process

Examine the end result from laser cutting

The bits and pieces of cotton fabric is easily removed

Examine the expectations between human's mental visualization and the digitally fabricated design.

Now, time to realize some of yours truly digital apparel designs that are ed-hardy-ish