About

The laser cutter room is part of the Digital Fabrication lab (DFAB) and has six 120W laser cutters and one downdraft table used for sanding. Each laser has a corresponding name and token to help distinguish which laser(s) is/are in use. Students can create a variety of projects with the laser cutters and save a lot of time in comparison to 3D printing. Laser cutting training is the most requested training, and must be done online with an in person check that you can sign up for on the portal. Any engineering student and staff member can use this area for class projects, research, or technical or personal projects as long as the required in-person training has been successfully completed. The laser cutters provide clean, quick and precise cuts on materials such as wood and acrylic. After finishing a project, it can be taken to the downdraft table, sanded to give it a nice finish, and then coated with one of our stains. Projects can be designed in softwares like RetinaEngrave v3.0, Illustrator, Inkscape, SolidWorks, etc. while waiting to laser cut. Texas Inventionworks sells wood and acrylic for your convenience.

Contents

Full Spectrum 120 Watt Lasers TRAINING REQUIRED $$$

About

Laser cutters use a high-powered laser to cut 2D vector files and etch pictures into wood, acrylic, and other materials with extreme precision. Laser cutting can be extremely helpful when prototyping ideas or when you want to make your project stand out. The laser room is known for being cold. We recommend you bring a jacket or something to keep you warm if needed.

Access and Training

• Training includes an online portion that will take about an hour to complete followed by a in person 15 minute check. The online training contains a series of 4 videos covering safety, designing on RetinaEngrave v3.0, TIW procedures, and how to use the Full Spectrum Lasers. Each part is followed by quiz questions and at the end there is a link to a RetinaEngrave preview in which you will design something to cut in your in person review. Once in person, you will use the machinery and staff will make sure you understood the training. 
• Here is the link to the online training session
• To reserve a laser or sign up for training, visit the TIW Portal
• Upon completion of the in person laser cutter training check, your UT EID will be saved on our Texas Inventionworks records to use for confirmation in the future.
  
• If you would like to review what was covered in the training, visit this powerpoint. This is NOT a substitute for training, but can act as a nice refresher. There is always someone stationed in the laser room so PLEASE ask if you have any questions.

Safety Procedures

The laser cutters can cause a lot of issues if they are used improperly or inadequately supervised. You are expected to watch the laser cutter carefully while it is running to check for any signs of fire, malfunction or material disposition at all times--NO exceptions. It is expected that all material rules are followed, since the use of inappropriate materials can cause illness, fire, injury and harm to the machine. You must wear safety glasses found in the laser box at all times while the laser cutter is running. 

In case of fire: press the red emergency stop (E-Stop) button, use the fire blanket located next to the laser cutter or the fire extinguisher found in every corner of the laser space. Please alert a staff member immediately.

Material Information

The following materials are approved to use on the laser cutters. Laser cutters cannot cut metal or glass, but they can etch glass. If you need to etch something on a spherical surface, talk with a staff member about using the rotary tool.

**If you bring your own material to laser cut, you must bring the corresponding Material Safety Data Sheet (MSDS) for approval. Please go to the Garage (EER 0.618) and ask to meet with Steve Ferraro for approval. If you are a part of a research group and would like to try laser cutting different materials, please email Steve Ferraro to schedule a time to meet with a trained laser staff member to help.

Cost

Texas Inventionworks offers wood and acrylic of different sizes and widths at inexpensive prices. The following materials are available for purchase via Bevobucks in the Garage (EER 0.618):

Important things to note:

• • There is no cost to use the laser cutters, if you already have material. 

  • Anything found in the scrap bin is completely free of charge. 

  • Please tell someone at HQ, or email texasinventionworks@gmail.com a day in advance if you need a custom sized piece of wood or acrylic so that we have time to cut it. We will charge by square inch. We may not be able to complete all requests due to sizing issues (too small or too large).

Software - RetinaEngrave v3.0

About

There are two ways a laser cutter can work: Vector Cutting and Raster Engraving. Rastering is used to engrave images, and vectoring is used to cut or engrave precise outlines and shapes. There are many different softwares that may be used to create or design your projects like RetinaEngrave v3.0, Inkscape, Adobe Illustrator, SolidWorks and Microsoft Word. Staff may not be proficient in all of these softwares, but part of the in-person laser training covers how to use and design things in RetinaEngrave v3.0.

Vector

A vector file consists of paths and shape profiles for the laser to follow. These profiles can either be created within RetinaEngrave v3.0 by using the Shape or Text tools or imported from .pdf files. Vectors are used to cut out shapes, which can then be assembled into mechanisms, boxes, structures, or used on their own. The depth of the vector cut, and therefore whether it cuts out the object or engraves it, is determined by a number of things, such as the power and speed settings, the material type, the thickness of the material, and the number of passes. To determine which settings to use, consult the power/speed charts located at each laser and perform your own test cuts. 

Raster

A raster file consists of a collection of pixels. These can be imported as regular images with file formats of .png, .jpeg, .gif, or .tif. The laser engraves raster images by sweeping across the image, turning the laser on and off very rapidly to engrave each pixel one by one. Raster engraving takes significantly more time than vector cutting. Within rasters, there are two additional options: Halftone Dither or Threshold. Halftone Dither allows for much more detail and variation in shade, while Threshold separates the image into large chunks of black and white. A raster file can also be converted to a vector using the Vectorize function. This works particularly well for images with clear lines and lots of contrast, such as clip art or logos, but can be done with any image. 

We use RetinaEngrave v3.0 software to upload files or design our projects. This software is 100% browser-based and has several built-in features that help alter the power and speed settings of the files that you want to cut and engrave. Each laser at TIW is connected to a desktop and can be used to access this software. Open Google Chrome and type the Wired IP address found on the laser in the URL search bar. If you would like to familiarize yourself with the software, you can access it here: https://re3.azurewebsites.net/designer.

Importing CAD Files

When cutting parts designed in 3D, it is important to save them as a vector file format to preserve the dimensions and precise nature of the paths and ensure a cleanly cut part. The optimal way to convert a file from a 3D CAD program, such as SolidWorks, Autodesk, or Fusion 360, is to save a drawing of the desired view as a PDF. PDF files contain vector data as well as raster data. Upon importing the PDF into Retina Engrave v3.0, you will see both the vector file and raster file, one on top of another. The vector file contains all the data needed to cut out the part, so the raster data can be hidden or deleted. The Subselect tool can be used to remove any unwanted vector paths such as center lines, informational text, borders, etc.

Resources

• 2020 How to Use the Laser Cutter Powerpoint
• Retina Engrave/ Full Spectrum Lasers Youtube Tutorials. 
• Basic Workflow 
• Vector Order
• Threshold and Dither Difference
• How do Laser Cutters work?

Troubleshooting

Smoke Buildup

Under normal use, the laser cutter produces a small amount of smoke as it cuts, but the exhaust system removes it fairly quickly. If you see the laser cutter accumulating smoke as it operates or there is a strong smell of burnt wood or acrylic, pause the job (you do not need to stop it because you will have to restart the job on a new piece of wood) and immediately alert a staff member.

Autofocusing

When using the autofocus feature, it is critical to make sure the gold focusing pen is located above the material. The focusing pen is the gold piece located next to the black laser head. When the laser autofocuses, it raises the bed platform until it senses that the gold pen has touched the material. If the focusing pen is not directly over the material, the bed will continue to raise, since the pen will not make contact with the material, which can cause significant and costly damage to the machine.

Before removing a vector cut object, check to see if it cut through without moving the material. If the cut did not go all the way through, it is very hard to reposition the object in the exact place it was before, and may result in two slightly offset cuts. You can check this by placing one hand on the bulk of the material while using the other to lightly wiggle the part that should be loose. If the part appears to still be connected to the bulk of the material, perform another pass and modify the power and speed settings accordingly for future cuts. If you have a thick piece of material, please do multiple passes at higher speeds rather than cutting through the material in one pass with less speed. Attempting to use low speeds to cut through material has resulted in fires.

Vector Order

The order you cut your vectors matters. You want to make sure that the outside border/outline of your project is cut last. This ensures that the material will not move or fly away while completing all engravings or cuts inside of the border. You can do this by changing the color of your vectors and placing them in the order in which you would like them.  

Please make sure you do not slam the door, it is heavier than it looks.

Examples

Grizzly Downdraft Table - Sanding Station 

About

The downdraft table has a built-in ventilation system to capture and help draw the excess dust away from the material being sanded. In order to sand a wood project down, check out a sander and sandpaper from the Garage. Sanding wood projects, especially those that are rastered, removes minor wood burns caused by the laser cutter, makes pictures clearer and gives the project a smoother finish.

Access

The downdraft table is used on a first-come, first-serve basis. No formal training is required to use the sanding equipment, but please ask a staff member if you need help. You must check out a sander from the front desk in the Garage! If your piece is small, it might be better to check out a piece of sandpaper from the Garage and sand it manually instead of using the sander.

How to Use

• Put on safety glasses

• Turn on the downdraft table

• Plug the sander into an outlet

• Make sure the sandpaper is usable (not too worn down) and properly placed on the sander

• Use the blue clamp to hold your piece in place (optional)

• Press the black power button on the sander’s handle to start

• Gently sand your piece 

• There are different levels of grit for the sandpaper that produce a smoother or rougher surface, depending on the level

• Hold down the power button to turn the sander off

• Turn off the downdraft table

• Remove the bag of dust from the sander

• Throw away the excess dust in a trashcan

• Put the bag back on the sander

• Unplug the sander and return it to the Garage

Cost

The downdraft table, sanders and sandpaper are free to use for research, class, engineering student organizations and engineering student’s personal projects.

Materials

• Random Orbital Sander

• Rectangular sander

• Different grits of sandpaper for the sanders

• Different grits of dry sandpaper for manual sanding

Resources

• Sandpaper grit is measured by the number of abrasives per square inch. For example,  120 grit sandpaper only has 120 particles per square inch, making it much more abrasive and leaving a rougher finish than, say, 1500 grit sandpaper

• A good sanding job typically starts with lower grit, coarse sandpaper, which allows for more material to be removed, and then works up to a higher grit sandpaper, leaving a smoother finish. 

• Additionally, if you are sanding by hand, make sure to sand in the direction of the wood grain. Doing so leaves a smoother finish, as it removes less material at a time. This does not apply to the orbital sander.

• How to sand and what sandpaper grit you should use

• Understanding sandpaper grit