The faster the engraving beam of the laser can move, the more engraving can be accomplished. A common issue we discuss with our customers is the ability to laser engrave in high volume. The efficiency of your laser can be best described in Parts per Hour. Tracking your parts per hour is an excellent method to measure the productivity and profitability of your laser system. Quick and accurate setups for each new order will make a dramatic effect on the productivity of your laser and are the key to increasing your parts per hour.
The typical questions from laser system owners include, "How do we accurately position dozens of parts to be engraved on the engraving table?" and "is there a way to layout the graphics and text to engrave on each part?"
An engraving fixture will allow us to exactly place the part on the engraving table and a software template will allow exact placement of the graphic and text. The software template will be used in conjunction with the fixture on the engraving table to accurately position the parts to be engraved. Templates and fixtures are the best way to increase the parts per hour of your laser system.
Creating software templates
The software template will represent the outside dimension of each part and include the graphic and text to be laser engraved. Any layout software that can interface with your laser system can be used. Some common layout programs used include Corel DRAW, Adobe Illustrator, Engrave Lab Laser, and Xenetech Graphic Workstation. Since many laser owners use Corel DRAW, we will illustrate how to create templates using this software application.
To get started, create a new page that is the size of your engraving table by clicking on the landscape mode, then entering the width and height values. Once the page size is ready, we can create a vector outline of the part to be engraved.
Lay the part flat with the engraving surface facing up and measure the dimensions of the item (In this instance we will use a pen holder which measures 4 inches high and 3 inches wide).
Now we can go to our blank page in DRAW and use the rectangle tool to create a 3 x 4 " rectangle. When positioning the rectangle, start in the upper left corner and duplicate (CTRL + D) until you have created enough rectangles for the row (leave about ½ in between each row).
After the top row is completed, select all of the rectangles on this row and duplicate them below the first row. Leave about ½" between the two rows. Later in the process we will be using the laser to vector cut these rectangles so be sure the line width for each of them is the correct width to allow your laser system print driver to see them as vector cutting lines. To verify make sure the width of the rectangle lines is less than .003 inches, select all of the rectangles and use the Outline Pen Dialog option from the Outline Tool.
Using the Object Manager
We have just created the positioning portion of our template. Now it is critical to lock it in place by using the Object Manager function. Locate the Object Manager by clicking on 'Layout ' on the top menu and then click on 'Object Manager'. The Object Manager will pop up on the right side of your screen. The Object Manager allows us to layer the graphics like a cake. Using the Object Manager we will be able to select specific layers and send them to the laser. In the Object Manager dialog box you will see several icons next to Layer 1. By selecting one or all of these icons we can easily change the attributes of this layer. Select the 'eye' icon to make the layer viewable or click it off and the layer will disappear from the layout. Select the 'printer' icon and you will no longer be able to send the selected layer to the laser. And finally, select the 'pen' icon and this will lock the layer from being edited. Click on the pen icon now and try to select one of the objects in the layout. You will find when the pen icon is a light gray color the graphic on that layer will not be able to be edited. This layer is now effectively locked and no changes can be made.
Creating the graphic layers
The final step required to complete the software template is to create a new layer in our graphic layout for the text and graphic. First, create a new layer by right clicking on the Object Manager or by selecting the New Layer icon at the top left of the Object Manager. It is easy to verify which layer you are working on by looking on the Object Manager screen for the layer that has its' name in red text.
With the new layer selected in the Object Manager you can now add your text and logo to the first product outline. (Make sure the logo and text are sized and positioned correctly). Once the first design is completed, simply use the duplicate function creating new engraving graphics for each of the product outlines. When the layout is complete, be sure to go back to the Object Manager and click on the pen (edit) icon for this layer. Turning off the edit feature for the graphic layer will eliminate any possible moving part of the layout.
Laser Cutting the Fixture
Now that we have created a software template, we need to make the fixture to fit inside the laser. The concept behind the fixture is to give us an accurate position guide so we can place the items to be engraved in exactly the right spot on the engraving table. The laser cut fixture will fit on the engraving table and push up against the rulers that are on the top and left sides. Fixtures can be laser cut from various materials, which include acrylic, engraving plastic sheets and thin wood.
Check the focus of the material you will be cutting making sure it is pushed up against the rulers on the engraving table. Refer back to the software template we just completed and make the graphic layer (layer 2) non-printable, by opening the Object Manager and clicking on the printer button for layer 2. Now you are ready to print the job over to laser. With the graphic layer now turned off, the laser will only see the vector lines for cutting the product outlines.
Ready for Engraving
Position your items in the open rectangles of the fixture. Double check the focus of the laser on the top of the item. Refer back to the layout and now make the graphic layer (layer 2) printable. Be sure to make layer 1, the product outlines, non-printable by clicking on the printer icon for this layer. Print the job to the laser using the correct power and speed for the object we will be engraving. After the first batch has been engraved, swap them out for blank products and press the start button on the laser again.
By using fixtures, you will be able to increase your parts per hour! Now all you have to do is let the laser do the hard work while you just swap out the blank products.
Variations on the theme
Frequently we are testing new materials and products and have just one, usually odd shaped item to engrave. Instead of making a full blown fixture and template as we described we use a shortened method to give the same result.
By drawing a vector to represent the item to be engraved, then applying a paper mask to the engraving table, a quick placement fixture can be created. Some of the latest scanners make this job even easier and allow you to scan the part and create an exact vector outline. The paper mask applied to the engraving table can be cut at high speed and low power and takes very little time to create. The item can be placed on the cutout and engraved without much fanfare or experimentation.