Working with Encore EconoFlex Material

Material – Engravers Express EconoFlex .025 thick plastic engraving material. This material is available in Brushed gold, silver and bronze. The core is made up of acrylic for easy cutting by lasers. The material can have 3M adhesive applied to the back of the material.

Application – Trophy Plates

Why Use EconoFlex?  When it comes to creating an engraving plate there are a number of steps involved. Aside from setting up the plates in CorelDraw and entering the text you have to engrave the plates, cut them out with a shear and then tape them. Note: some customers require either a scallop or a radius corner to help “spruce” up the plate. Using EconoFlex allows us to speed up our job for a number of reasons.

The “metal” top of the EconoFlex requires less power than black brass coated steel. This means that we can run our job at a faster speed even on lower power lasers

Because the thickness of the EconoFlex is only .025 a laser even one that is 25 watts can easily and quickly cut out the plates once the engraving is done. The material cuts very easy with no flaming because it is thin and also because the core of the material is acrylic.

Because the base colour is black the plate is easily read even when the text is small.

Because the laser can cut out the EconoFlex there is no need to just cut the material so that we get square corners. We can easily add a scallop or a radius corner. This can greatly increase the perceived value of the plate.

With the material having adhesive pre applied to the material once the plate has been cut out we can quickly peel the adhesive and stick it onto our award product.

How to create our multiple plates in CorelDraw

First of all we need to create a plate that is 3 by 1 in size – see Figure 1

Figure 1

Next we need to place in our text. For this example let us place in 3 lines as per figure 2. To center the text on the plate press the “P” key.

Figure 2

Next we need to cut out the rectangle box that will be our plate cut out. Select the rectangle tool in the toolbox as per figure 3.

Figure 3

Now draw the rectangle box inside our 1 by 3 plate. The rectangle will be our cutout for our box. This box is a vector line (hairline width) so it will signify to our laser that we want to cut it out. To accomplish this you need to left click your mouse and while holding it down drag from the top left hand corner to the bottom right hand corner. Do not worry that the rectangle is not exactly 1 by 3. Figure 4 shows the rectangle being drawn. The little rectangle box that is attached to the cursor indicates that the rectangle tool is active.

Figure 4

Now we need to make our rectangle exactly 1 by 3. There is a problem here and it is that CorelDraw will not allow us to go right to the edge of the page. We need to be within .005 thousandth of an inch of the edge of the page. For this reason we need to make our plate 2.990 by .990. If you need to make a plate that is exactly 1 by 3 than you will need to make your plate 3.010 by 1.010. This will allow you to make a plate that is the right size.

To make our engraving plate the proper size we need to select the rectangle with the pick tool. Now in our property bar we need to type in 2.990 by 0.990. Figure 5 – red box – shows us the location in the property bar.

Figure 5

Once we have resized the box we next need to center the box. Figure 5 – blue box- shows the numbers that need to be entered in for the box to be centered on the page. Once you are done entering in the number press the enter command.

Now that we have centered the box we need to place in a .15 inch fillet on each side of the rectangle. To open up the fillet/scallop/chamfer docker go to WINDOW | DOCKERS | FILLET SCALLOP CHAMFER. This will open up a docker on the right side of the window. Now select “Scallop” in the drop down box and .15 of an inch for the radius. Figure 6 shows us our settings.

Note: the fillet/scallop/chamfer feature is only available in Corel X3 and X4

Figure 6

Click on the apply button in the fillet/scallop/chamfer docker. Figure 7 shows our finished plate. Note: I have outlined the box in red to make it easier to see.

Figure 7

Once we have created our master plate we can send it to the laser machine. We can use a number of different techniques to create this multiple. For this exercise I will use the imposition layout command. This command is located in the print menu.

First we need to go to FILE | PRINT in CorelDraw. Figure 8 shows our print menu that comes up. Select your laser machine driver and then click on the “properties” button.

Figure 8

Once we are in our laser print driver software we need to set a couple of parameters. For this example I will be using a 12 by 24 plate size. I have set my settings for a 35 watt Epilog Helix. The raster setting is the marking part of the job while the vector setting is the cut out – see Figure 9. Once you have your settings inputted click the “ok” button and you are back in the main print screen as per figure 8.

Figure 9

To create our multiple plates using the “Imposition Command” we need to click on the “Layout” tab located at the top of the print menu. Figure 10 shows the layout tab opened. You need to click on the “Edit” button that is located at the bottom of the screen. I have outlined it in red.

Figure 10

Once you are in the imposition command your screen will look like figure 11. The first thing that we need to do is type in the number of columns that we need in our job. Our plate is 3 inches long and our multiple plate is 24 inches long. Thus we can get 8 columns (24 /3). Our plate height is 1 inch so we can get 12 rows (12 /1). So we need to enter in 8 by 12 for our columns and rows respectively – see the red box in figure 12. Once you have inputted the second value you can press enter.

Figure 11

Your screen will change to a number of plates on a 12 by 24. You will not be able to see the plate information at this point. To see the plate information click on the “Preview Template” button located next to the input boxes – see the red box in Figure 12.

Figure 12

Once you have clicked on the “template preview” button you will see all your plates copied to the 12 by 24. Figure 13 shows some of the plates that we have created.

Figure 13

Once you are done click on the “Check Mark” icon located at the top left hand corner – see Figure 14.

Figure 14

You will be brought back into the print dialogue box. Click “print” and send the job to your laser machine.

For more information on the imposition command visit www.engrave.ca

Cutting the EconoFlex with a Laser

The following instructions are listed here to help you in setting up your laser to cut the EconoFlex. For this example we will use an Epilog laser 25 watt mini. All powers and speeds will be based on this machine.

The most important thing that you can do when you are first working with this or any material is to practice. When it comes to working with this material you will need to “tune” your laser to mark the material properly and to cut the material just right. When I say cut the material just right I mean you need to use just enough power to go through the material. If you use too much power you will over cut the edge of the material and disfigure the material edge.

Determining the proper raster setting

When it comes to determining the proper raster power and speed setting most laser users will send a number of jobs over with different power and speed settings hoping to get the right power and speed. This is fine but in the end everyone gets mixed up. My suggestion is to draw a black rectangle and send it over to the machine with power and speed settings that are close to what is needed. Press the start key on your laser. As the machine is engraving adjust your power setting directly from your machine until you are actually not burning the material enough. Thus you are using to little power. Now increase the power until you are getting an acceptable burn. Increase the power a couple of percentage points to account for variations in power across the table. Figure 15 shows the black box created in CorelDraw.

Figure 15

Once you have the proper settings save the settings in your laser driver – see figure 16.

Figure 16

Fine tune your vector settings by adjusting your power till you just go through the material. I tend to like to have to snap it a bit when I am taking the material out

Now that we have the proper settings all we need to do is to send the job to the laser machine.

Take your 12 by 24 piece of EconoFlex and place it on your table preferably on the cutting table if you have no adhesive or on the normal table if your material has adhesive on it and you are just cutting through it. Figure 17 shows the material on taped down. I have placed the three sides under the rulers to hold them down. It is imperative that this material is flat. If it is not flat than your laser will not cut it properly.

Figure 17

Figure 18 shows the plates cut out on the table.

Figure 18

For your information the total job time was 31:23 minutes or 1 plate every 20 seconds. Impressive and definitely a time saver especially considering that it goes right on my award and requires no more processing (If I have adhesive on the material).

Doing a Belt Change on an EX Laser Machine
By Mike Clarke
Jun 8, 2003, 21:33

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Doing a Belt Change on an EX Laser Machine

Changing an X drive belt is quite easy on the EX laser system. This file walks you through it.

Tools Needed
• Philips (Star) screwdriver
• Stapler
• Allan Wrench

1. First we need to remove the gray panel. There are 6 screws that need to be removed. 3 on the back and 3 on the front. They have a Philips head. Figure 1 shows two screws that are located on the left side of the front of the arm.

Figure 1

2. Next remove the gray cover as per Figure 2.
3. Now we need to release the tension on the belt. To do this if you look on the left side of the arm and at the back you will see a belt tensioning screw/spring. With you screw driver loosed the screen and than push the spring to the right.

Figure 2

4. Next tighten the screw up so that the belt can not “spring” back to its original position. See Figure 3.

Figure 3

Now you need to remove the belt. With your Allan wrench remove the two screws that hold the left side of the belt to the arm/lens assembly. See Figure 4, 5, and 6.

Figure 4

Figure 5

Figure 6

6. Repeat this procedure till the belt is loosened on booth sides of the lens assembly.
7. Now staple the new belt to the old belt with the new belt being on the left side and the old belt being on the right side as per Figure 7

Figure 7

8. Now carefully pull on the belt that was attached to the left side of the lens assembly. This will feed the old belt through the right side of the arm and pull the new belt through. Be careful so that the belt does not come loose from the old belt.
9. Now that the belt is pulled through all you need to do is reattach the belt to the lens assembly.
10. Figure 8 shows how the belt sits in the groove of the “clamp”.

Figure 8

11. Place the belt in the clamp and than screw it back onto the left side of the assembly. See Figure 9.

Figure 9

12. Next repeat for the right side.
13. Now all you need to do is release the tension and the belt retention back. See Figure 10.

Figure 10

14. Place the cover back on and than run a test.

© Copyright 2003 by Awardline.com

Setting Rotary Position to Home Upon completing the installation procedures for your Rotary attachment, you will want to ensure that your home position is aligned correctly. The following will guide you through this alignment. The Red Diode Pointer 1. Using the left and right arrow keys on your LCD Display, select the SETUP button the LCD Display. The Diode Pointer projects a red beam of light, which will pin point the home position of your rotary attachment. 2. Using the down arrow keys, scroll down to the “Diode Pointer” and select “Yes” by turning the round knob on the display to the right. Press “Enter”.

Figure 1

3. The Diode Pointer should be centered at the edge of the rubber bumper on the attachment. 4. If the red beam is not centered correctly, the following steps will guide you in adjusting your home position manually utilizing the Calibration settings on your LCD Display Panel.

Figure 2

Adjustment of Your X Home Position 5. Leaving your Diode Pointer on, press the right arrow key on your panel and scroll to the “Service” option, press “Enter”. 6. This will display a drop down list of 5 options, using your down arrow key, select “Move X/Y”. Press “Enter”. 7. Once you have selected “Move X/Y”, you will now see your X/Y coordinates located in the center lower screen of your display. 8. Using the left and right arrow keys on the LCD Display Panel, you can now move your X carriage to the center point of the drive wheels on the attachment.

Figure 3

Note: Because of the curvature of the rotary, your diode pointer may not be centered until completion of your Y Home Position adjustments. Once you have determined the center point, record the numbers that are located in the lower center of your display (see above diagram) and convert this number to 1,000’s of an inch. Calibration Settings 9. Press the “Enter” key again to display the options under the “Service” menu heading. 10. Using the down arrow key, scroll to “Calibrate.” Press “Enter.” This menu allows you to set the machine’s operating parameters. 11. Using the down arrow key, scroll down to “X Rotary Home”. 12. By turning the round knob on the LCD panel, you can adjust the coordinates of “X” Home position. You may enter coordinates from + 200 to – 700. Decrementing this number will move the carriage to the left, while increasing the number will move the carriage to the right.

Figure 4

13. Adjust the coordinates to reflect the position noted when manually adjusting your X carriage position in step 2. Press “Enter”. Saving Your Settings 14. Using the left arrow key, scroll to the “Options” menu heading and press “Enter.” 15. Using the down arrow key, scroll down to the “Save Settings” option. Press “Enter”. You have now saved your X Home changes. 16. Return to the “Service” options menu. Using your down arrow key, scroll down to the “Reboot” menu heading and press “Enter”.

Figure 5

Note: This option must be selected; Do not reset the machine to avoid this step. Your machine will only look for home when it has been rebooted. 17. Repeat Section 1 – Red Diode Pointer Adjustment of Your Y Home Position 18. With your Diode Pointer on, press the right arrow key on your LCD Display panel and scroll to the “Service” menu heading, press “Enter”. 19. This will display a drop down list of 5 options, using your down arrow key, select “Move Y Beam”. Press “Enter”. 20. Once “Move Y Beam” has been selected, you will now be able to move the Y position of the I-beam with your up and down arrow keys on your LCD Display.

Figure 6

Calibration Settings 21. Referencing Step 3 – Calibration Settings, follow the same guidelines with the exception of selecting your Y Rotary Home Position. 22. Using the down arrow key, scroll down to “Y Rotary Home”. 23. By turning the round knob on the LCD panel, you can adjust the coordinates of “Y” Home position. You may enter coordinates from +200 to a – 200. Decrementing this number will move the carriage towards the front the machine, while increasing the number will move the carriage towards the back of the machine.

Figure 7

24. Repeat Step 4 – Save Your Settings

© Copyright 2003 by Awardline.com

Using the Epilog Rotary Attachment

Files

http://www.engrave.ca/files/mug_template_v8.cdr
http://www.engrave.ca/files/mug_template_with_different_turns_v8.cdr
http://www.engrave.ca/files/mug_template_with_no_turn_v8.cdr
One of the more intimidating techniques to learn on the laser engraver is how to use the rotary attachment. This help file should help eliminate any misgivings you may have.

1. If your table is not lowered than lower it down about 5 inches
2. Turn the power off to the machine
3. Plug in the rotary machine (the plug is under the left side of the machine (EX or LX and the front of the machine on the TT).
4. Turn the machine on.
5. The machine will know that the rotary attachment is plugged in and the X axis will settle over the attachment – see Figure 1.

Figure 1

6. Place your glass item in the attachment. Now the big question is where do I place my image? To answer this let us look at setting up the image in CorelDraw first.

Setting up your image in CorelDraw

7. The first thing that we need to do in CorelDraw is to create our page size. There are 3 ways you can determine the page size that you need to create. Remember setting up the rotary attachment is just setting up any other job. You need to create a page size that corresponds to you’re the area that you need to engrave on.
8. Create a new blank document in CorelDraw. With nothing selected you can set your page size by entering the size in the property tool bar. See blue box in figure 2.
9. How do we figure out each dimension? The page width is determined by the length of the glass and how far it is from the origin of the rotary attachment home – which is the rubber bumper in Figure 3 – see the blue box.

Figure 2

Figure 3

10. Thus the width of the page is measured from the bumper to where you logo needs to be. If we look at the mug – in Figure 4, if we want the logo to be in the middle of the glass than we measure from the bumper to the location of the bottom of the logo. Actually it does not really matter what the size is as long as it is longer than our location. The red line in Figure 4 would be what I would use for the width of the page. The glass is up against the bumper so I have created a page that corresponds with the length of the glass from the bumper.

Figure 4

11. Usually the tricky part of setting up the page size comes when we try to figure out where we want the image to appear on the glass – which is our page height (the text or logo is turned 90 degrees.
12. Let us assume for this exercise that the glass we are going to work with is the same diameter through out the total glass.
13. To figure out the page height first we need to measure the diameter of the glass.
14. Next take that figure and multiple it by Pi or 3.14. This gives us the circumference of the glass.
15. For example if the glass is 2.75 inches in diameter than we multiple 2.75 by 3.14. This gives us a value of 8.635. Thus our page height is 8.635.

Note: There are two other ways you can figure out the “wrap” of the glass and where the image is suppose to go. First you could place a flexible ruler and wrap it around the glass. This will give you a very good measurement. Secondly you could wrap a piece of paper or a piece of masking tape around the mug – see figure 6. Pull the paper off the glass and than measure the paper. You can also draw where the logo is supposed to go and this would help with your logo placement – see figure 5.

Figure 5

Figure 6

16. Figure 7 shows how I set up the page setup to do an inboard and outboard design on my glass mug. This job was done as one job and the glass traveled almost all the way around. Remember that the laser works down the page. Thus we need to turn the image 90 degrees. The left side of the page is where the top of the glass buts up against the bumper.

Figure 7

17. Once we have the glass setup done in CorelDraw we need to place the glass into the rotary attachment. Because the handle is a little longer I needed to take off the outer rings of the rotary. This is quick and requires taking the 4 thumb screws out – see figure 8 (note the outer rings are for heavy items that require more power to turn). We use this type of system because if we use a cone system heavier items such as beer steins fall out.

Figure 8

18. Figure 9 shows the position of the glass before we start engraving.

Figure 9

19. Once the file is created we need to send the file to the laser. The only thing we need to do in the printer driver is to change the laser page size to match up with page size in CorelDraw. Figure 10 shows the page setup size in the Epilog print driver

Figure 10

20. For this glass I engraved it on a 35 watt machine. I set the power and speed to 100 and 100.
21. Figure 11 shows how much the glass turns before it starts engraving as per the file in figure 5. Remember that the handle was straight up and the handle has passed under the x axis arm. The distance it travels before it starts engraving is the distance of the green arrows in Figure 12.

Figure 11

Figure 12

22. * If you where to put the logo right at the top of the page than the glass will not turn at all before it starts engraving. If the handle was really big and would not go through the arm than you would place the image right at the top of the page. See Figure 13.
23. When it comes to glasses or other items such as wine glasses or bottles that do not have a handle than it does not matter where you place the image. Wherever the image engraves is fine. I would suggest that you place it at the top of the page. Why turn the glass if you do not have to.

Figure 13

24. You may be wondering what direction that the rotary attachment travels? Figure 14 shows you the direction. The circle represents the base of the glass in figure 11 as if you where looking at it from the right side of the machine. Thus the glass in figure 11 will move away from you if you are standing in front of the machine or in a clock wise direction as per figure 14.

Figure 14

25. If you would like to see the actual file all you need to do is down load the help files.
26. If you would like to get an exact position of where the image is going to engrave on the glass than the easiest way is to draw a box around the image as per figure 15 – make sure that it is a vector line.
27. Make the engraving speed parameters about 20 do not worry about the power as we will not be burning the job.
28. Next send the just the vector line to the machine. The best way is to select the box and in the printer driver say process only your selection. Go to the machine and under the “setup” menu move down to the red pointer and turn it on. You will see a red light emanating out of the machine.
29. Now place the glass in the rotary attachment.
30. WITH THE LID UP run the job. You will notice that a red line is created where the machine engraves. The square is the area that encompasses your engraving and thus gives you an exact placement of the area.
31. If you are really worried about the placement you can place tape on the area that needs to be engraved and use a low power.

© Copyright 2003 by Awardline.com

Laser Basics

Although we do not need to spend a lot of time on understanding how the actual laser machine works there are some things that need to be highlighted as they are important items that need to be considered when you are laser engraving.

Although I wanted to stay away from talking about laser tubes, more because it would be better told by an engineer, to know a laser is to know how the tube works.

Laser Tube Characteristics

The Laser Tube

The term laser is an acronym for Light Amplification by Stimulated Emission of Radiation. In its most simple explanation a laser is a device that converts electrical energy into optical energy. The light is amplified in the tube and is emitted from the tube traveling in a straight line at a single wavelength. The tubes are usually aluminum and are specially designed so that the gas stays sealed in the tube and does not leak out.

One characteristic of a laser tube is that they generate a lot of heat. Tubes need to remain below a certain temperature. If the laser tube gets to be to hot the laser tube will begin to lose its efficiency. To help maintain a stable operating temperature the outside walls of the tube have large heat sinks that conduct the heat away from the tube.

One thing to consider is that the CO2 laser tube is generally inefficient. This means that it generates a lot of energy but that a lot of this energy becomes non usable energy.

Bore and Mirrors

The bore has two purposes. The first is that it is where most of the optical energy is generated. It also provides the direction to the optical energy. Typically bores come in different shapes and sizes. The shape of the bore can greatly influence the shape of the beam. This can be important as beam shape can be advantageous and disadvantageous depending on your application.

The mirrors are mounted at each end of the bore. One of these mirrors is totally reflective and the other mirror is partially reflective. The mirror that is partially reflective is designed to allow some of the optical energy created in the bore to pass through and escape the tube. The optical energy that escapes is just the right size (wavelength) and moving in just the right direction (perfectly perpendicular to the mirror). The optical energy that escapes is the laser beam. The rest of the energy is reflected back into the tube and is not allowed to pass out of the tube.

Gas

The gas mixture in a sealed laser tube tends to be mostly CO2, with similar concentrations in nitrogen and helium gas. The actual mixture is kept secret by tube manufacturers.

RF (Radio Frequency)

All lasers are powered by radio frequency (RF) energy. The RF energizes the gas mixture. The energized gas becomes optical energy.

Different Types of Lasers

When we look at our industry there are 3 laser types that are prevalent. They are the Free Space Laser, the Slab Laser and the Waveguide laser. Each laser tube has its specialties and I will refrain from actively discussing the different tubes here.

Laser Machine Characteristics

DPI (Dots per inch)

As much as our laser combines a lot of unique technology we can look at it in its simplest form – as both a laser printer and or a plotter with a laser attached to it. Like a laser printer the laser engraver has different dpi settings. For example most laser engravers use a standard dpi setting of 500 or 600 dpi. What is dpi? DPI stands for dots per inch. If you engrave an image at 600 dpi there will be 600 dots in a linear inch of travel both horizontally and vertically. If you decrease your dpi to 300 than your laser produces 300 dots per inch in the vertical and the horizontal direction. One important point needs to be pointed out here. If you half your resolution from 600 to 300 than your engraving time is cut in half. Typically, as with laser printers, we find that the higher the dpi the better the quality of the engraving with lasers. This is true up to a certain point. Figure 24 shows a representation of how the laser lays down the dots at different dpi settings. Considering that the dots are always the same (as long as the power and the speed are the same) all that the different dpi settings do is cause the dots to be either closer or farther away from each other.

Figure 1

Figure 1 shows a representation of how the different dpi settings are spaced together.
The higher the dpi the more dots that are lasered in an inch of travel. The more dots transfers
into more time to engrave an image. 300 dpi engraves twice as fast as 600 dpi.

The closer the dots (remember that any item laser engraved is just a series of dots placed together) are to each other the better the quality the finished image will be. However if we look at the dots in the 1200 dpi representation you will notice that there is a lot of overlap. This overlap can be greatly exaggerated if we increase the power that our laser is delivering to the material. Thus what we find with the higher resolutions like 1200 dpi is that because of the tighter dot overlap our images tend to over engraved (too many dots) and will look worse than the lower dpi such as 600.

One other issue may become apparent is when you are looking at figure 25. Each of the sets of dots has 6 lines of dots. You should notice that the amount of space taken up by the dots is greater with the 200 dpi setting than the 1200 dpi. Thus the lower the dpi that we use the faster our machine will engrave. However there is a quality trade off. This quality will be dependent on the type of material that we use and the power and speed that we use. If we run a job at 600 dpi and the job takes 2 minutes to engrave, than running the job at 300 dpi will cause the job to run at approximately half the time or 1 minute. Note: I have always promoted that you should always try to use a lower dpi setting when you are engraving as it can greatly increase your through put. Considering that a lot of text we engrave is no bigger than an 1/8 of an inch no one is going to see the difference. The only problem we have with less dots is that you have less burning and most of the time you will have to increase your power to achieve a similar burn that you would get at the higher resolution.

Figure 2 shows the actual laser dots that are created by the laser machine. Most lasers create a dot that is more oval in shape. This creates a bit of a problem in cutting. The beam will be wide in the x direction and thinner in the Y direction – sort of like a paint brush.

Figure 2

Dot Gain

As we find with printing on paper dots created by the laser engraver are a certain size before the beam burns with the material. When the beam comes in contact with the material the dot tends to become bigger as the heat is absorbed by the material. The more power that is supplied to the dot the larger the dot becomes – this is because there is more heat which is absorbed by the material. I like to call this dot gain which is the same as we find with a printed dot on paper. A printed dot will be one size before it is placed on the paper. After the dot comes in contact with the paper the dot size becomes bigger. The more ink that is used the bigger the dot tends to become. Other variables such as paper will also influence the size of the dot that is created. Laser engraved dots are the same as the dots created on the paper. The more power that is supplied the bigger the dot becomes. The size of the dot is also influenced by the material that you are engraving.

It is this dot gain that can make or break a laser engraved image. Fine detail in an image can be greatly reduced when you apply to much laser power to your engraving material. Figure 27 shows an image that is created on some laserable black brass coated steel. The fine line around the outside of the image is perfectly engraved. However the bottom figure in Figure 27 shows that if we supply a little more power – even 3 more watts – the detail can be quickly obliterated.

Figure 3

Figure 4

So the trick when you are laser engraving is to practice until you come up with a power and speed setting that is perfect for both your laser and the material that you are engraving. You always need to take into account the dot gain that will be created by the laser. So create your samples and than compare those samples with different speeds and power to see what settings are the best.

Focal Length

The most important step that you can take to achieve good engraving on your laser is to make sure that you are in perfect focus. The laser beam functions the best when it is at its smallest point. If you remember back in your school days when you took a magnifying glass and moved it back and forth to focus the sun there was a point where you got a real small point. It was this fine point that burned the paper. If you moved the magnifying glass to far away than nothing would happen. This principle is the same as how the laser works. The laser machine is taking the laser beam and when it goes thought the lens it is being focused to a very fine point. The finer the point the smaller the dot sized that is engraved. Figure 28 shows the different lens that are available and what the dot (spot) size that each creates.

The most common lens (99% of the applications I come across) is the 2 inch lens. It creates a spot size of approx 5 thousand of an inch. For most people and most applications this is the only lens that you will ever need. The other lens are specialty lens and used for special engraving applications.

Because we are using a 2 inch lens in our laser than we need to be approximately 2 inches away from our engraving material. However we do not necessary have to be exactly 2 inches away. Figure 29 shows the beam actually straightens out for a short period before it starts to become larger. This straightened area is called the depth of field. Like a camera this area means the beam is still in focus. Each lens has its own depth of field. The bigger the depth of field the longer you can be out of focus. However as the chart indicates this comes at a cost in that the spot size of the laser is bigger. The 2 inch lens has a depth of field of .187 or a little more than 11/64ths of an inch.

Cleaning the System

One of your main enemies with the laser is dirt. The more dirt that is left in the machine the more issues you will have later on. Typically most manufacturers that I have seen have asked that you routinely wipe the machine down to keep it clean. I would suggest that you refer to your owner’s manual to find out what they suggest and what needs to be cleaned.

Also the optics (mirrors and lens) in the laser need to be cleaned. Dirty optics can rob you of power. I have seen machine lose half their power because of a dirty lens. So be diligent about cleaning your machine.

Figure 5

Table 1

Table 3

Note: some new optics have changed the above chart to smaller and more round dots sizes and shapes. Check with your manufacturer for up to date specifications.

The above table shows the each lens and how big the spot size is along with its best application.

Depth of Field

The depth of field is amount of distance that your laser is in focus. For example table 1 indicates that our depth of field for a 2 inch lens is .187 inches or a little over 11/64 of an inch or better still 3 sheets of Rowmark plastic. Thus you do have some room to work with when you making sure that you are in focus. Depth of field is the same as a camera. The amount of depth of field in a camera is how much of the image is in focus. The same can be said for the laser. If you are “are out of focus” than you are out of the .187 inch distance. Thus in theory to be out of focus is to be either above or below .187 inches from a 2 inch lens. Personally this is not a telling you to be careless with your focusing. What it is trying to tell you are that if your material is not entirely level or on a curve than you can have some leeway before your burning ability is greatly reduced.

You will also notice from Table 2 that the depth of field increase as the lens gets larger. Thus you can really do some items that are at different heights. I remember a customer that had to do some laser engraving on some large curved bases. The problem is that they where out of focus on a large part of the base. This caused inconsistent burning by the laser where one area was engraved deeper than another area. The use of a 4 inch lens greatly solved their problems. The larger spot size produced by the 4 inch lens was not an issue as they were engraving on wood.

So the rule here is that an increase in depth of field is offset by a wider or large spot size. Thus you need to make sure that the wider spot size justifies the large lens. The other thing to consider is that all laser beams are not created equal. Although each can create a certain spot size the burning ability of a laser machine is largely dependent on the shape of the beam and the rise and fall of the laser. Certain beams produce better spots for certain materials.

Speed versus Power

When I am training people on the laser machine I have always felt that you need to run the job as fast as you can. Time is money and the less time it takes to do something the better it is to your bottom line. For this reason I always run the machine at 100% speed. At 100% speed you can adjust your power accordingly. However what if you need more power? Well if you are at 100% power the only way that you can achieve a deeper burn is to slow the machine down. By slowing the machine down you are placing more power at the point of burn. Thus, we can say that the depth of burn is inversely related to the speed of the laser. The slower the speed of the laser the deeper our burn will be – depending on the material.

When it comes to light products like plastic we can laser engrave it a lot faster than we can say with wood.

Power Needed

One trick that I do is to create a rectangle in CorelDraw. Send the job over to the laser with a power and speed. Start engraving the material. Now adjust the power and speed on the laser (most machines allow you to adjust the power and speed while the job is running. So check out your laser manual). Typically I will adjust the power until I am just getting through the material. Once through I increase the power a little more. Once I have this setting I save it in my preference file in the laser driver.

Pricing

This is always the $50,000 question and because of certain laws I can not suggest actual pricing. But I can say that a lot people will price based on time. For example if you were to charge $100 per hour and the job took 6 minutes than you need to account for that 6 minutes and charge $10. The one thing to remember when you are pricing and that is that you will eventually need to replenish this machine. Your pricing should include a slush fund so that you can replace your machine when it gets to old.

Pricing is always subject and there can be a lot of factors when you are setting a price. The best thing I can suggest is if you are in doubt than run a sample. The more you know about the job the more likely you are that you will be able to deliver a more competitive price.

The purpose of this section is to give you a brief overview of the laser machine. If you know how your machine operates than you will be able to maximize your output. Knowing the machine will also make it easier for you to create the best quality images that you can on your machine.