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What?

Perhaps you are unfamiliar with laser cutters, as I was when I first learned of them. They are conceptually simple. As most people know, focused light is capable of damaging eyes and burning paper (or ants). However, if you can generate enough photons and focus them onto a small enough point, you can do much more amazing things — from cutting metal to etching paper.

This is intended to be a preliminary project for building a significantly larger laser cutter in the future (perhaps 16'x16'x10' — or larger). This does not, however, mean that it will be useless. It is full intended to turn this into a fully functional laser cutter in the future, as I need something with which to test my first custom built laser.

Why?

During my studies at the Georgia Institute of Technology, I have had the opportunity to see and use a laser cutter. I was very interested in its design and potential uses, but found myself disappointed in the limitation in size and materials it could work with. I decided to attempt to build my with a larger work area and not limited to one specific laser.

The reasoning for choosing this size as a starting point is that, at a 2'x2' working area, you begin to max out the practical ability of many methods of constructing such a device. For example, using drawer slides, as I have here, is not terribly practical from a cost perspective, and becomes significantly less so as you increase in size beyond these dimensions.

Components

Previously mentioned is that this project is a preliminary step toward a large format, fully featured laser cutter. It is, also, a school project for which I will be graded, as such it does need to be completed in a timely manner and for not an unreasonable amount of money. Due to these restrictions, a laser powerful enough to cut anything will not be found in the details of this project, though one is planned for the future. Instead, a small, inexpensive laser is going to be used for testing and demonstration purposes.

Below is a list of supplies and their approximate costs. Everything listed can be bought from Home Depot except for a few items to which the source was provided.

Do note that many of these items could be bought for less with better shopping and less strict time constraints.

I have alsos not yet purchased all of the necessary parts to complete my project.

The lack of pricing on the power supply and mirrors is due to a lack of having selected the specific item to be purchased yet. With respect to the mirrors, their selection process involves determining whether I want to purchase higher quality mirrors which may work for high powered lasers or use a cheap reflective surface or bathroom mirrors in order to reflect the laser for demonstration purposes.

The power supply is another issue, however. I know relatively little about powreing multiple electronic devices (such as several motors) without damaging any of the components, and thus research is required in order to select the correct item(s).

Station

Currently, the project is held up by two minor and essential issues. The first and foremost is the need to connect the shaft from a stepper motor to the ¼" threaded rod which will be used to move the platforms. Several methods of accomplishing this task are being pursued.

Projections of work time remaining to be completed as well as work time compelted.
Fig. 1-1: Projections of work time Details

The first is to attempt to find a connector which is designed to accomplish this task. Unfortunately, this has been completely unsuccessful thus far. The backup plan to this is to simply epoxy them together.

Secondly, it is necessary to accurately attach the first platform to the drawer slides which will support it. If these components are not correctly aligned, then they will need to be repositioned — a time consuming process.

Once these two hurdles are overcome, it is just a matter of acquiring the remaining parts and assembling the unit. All of the major challenges have already been dealt with and will be detailed on this site.

Diagram of the base structure
Fig. 1-2: Top-down diagram of base structure

The base structure was built using the plywood as a base and placing two 26" boards across the width of the plywood, 24" apart. Then, two 24" boards are placed between them at the edges of the plywood, forming a 2'x2' square at the center. In this area, the two metal rods, cut down to 25" each, are placed in holes in the boards and the strong ties are spaced evenly across the rods.

Diagram of the X-axis systems overlayed on the base structure
Fig. 1-3: Top-down diagram of the X-axis system

Across the top and the bottom of the base structure run two tracks (bright red), and on these tracks will travel a platform (dark red). The platform will be moved by being attached via nuts (light blue) to the ¼" threaded rod which will be turned by a stepper motor (light blue). The stepper motor will be mounted to the base at the correct height and the threaded rod will be supported from below on each end (dark blue). The stepper motor will be controled by circuitry on the plywood base (green areas), and everything will be powered by a AC->DC power supply (gold). The laser will aim its beam at a mirror on one end of the platform, and that mirror will reflect it at a 90° angle parallel with the edge of the platform.

Diagram of the Y-axis systems overlayed on the base structure and X-axis systems
Fig. 1-4: Top-down diagram of the Y-axis system

Here, again, you can see the path along which the laser travels has been modified by the addition of two new mirrors on the top, and final platform (dark turquoise). This platform travels along the track (turquoise) and is connected to another threaded rod turned by another stepper motor. New circuitry is added to control this system and there you have it, a laser cutter.

Of course, during the actual construction, things may change slightly, such as the number of mirrors used. It is possible to get the desired effect using only two mirrors, however I have not yet decided if I want to use a three or two mirror design. And, of course, the positioning and layout of certain things can be changed without effecting the core design of the system.