In this Instructable we will use a test file to find out how the laser works with your material when it is cutting and engraving at different speed and power settings. We'll do this before we run our main project file so that we can optimize for the desired effect we want and minimize the time it takes to laser your project (and therefore the cost of it).
Step 1: Understanding Speed, Power, and Time
The laser machine has two variables we can play with: Speed, and Power. We want to play with these variables in order to minimize the time it takes to complete our project while still getting quality results. We want to minimize the time it takes because time = money. Literally, you are paying per minute of use of the laser, so let's make it go as fast as we can! Depending on if we are cutting or engraving, we'll optimize in different ways. But first, some definitions:
Speed is how quickly or slowly the laser nozzle will move around in the X and Y directions. Obviously the faster it moves, the less time it will take for your project to complete. Less time = less cost.
Power is how powerfully the laser fires regardless of speed. The more power, the darker and deeper your engravings will be and the thicker the materials we'll be able to cut through. If we increase our power, we can also increase our cutting speed without fear of not cutting through all the way. With an increase in speed, the less time it will take to finish your project and less time = less cost.
Step 2: Run Our Test File
Out test file is always loaded on the laser machine and titled MatTest. Run it by:
- Loading your material and setting the Z and origin
- Load the file (File > MatTest > Enter)
- Then press Frame
- If it looks good, press Start!
Step 3: Optimizing Our Settings
Our goal with engraving is to go as fast as possible while achieving the desired darkness we want. Our optimal settings for engraving are therefore maximum speed (200 mm/s), and whatever power level (darkness) you want for your project.
Our test file engraves a series of squares, all at a speed of 200 mm/s, and varying power levels all the way up to the maximum allowed power of 85. Find the square that you like the most and use those settings! Note: you can use a power setting in between the levels we provided if you want a middle-ground darkness.
Our goal with cutting is also to go as fast as possible. However, if we go at full speed and full power, we very likely will not be able to cut all the way through our material unless we're cutting paper. So we need to turn down the speed a bit to ensure we get through our material.
Our test file attempts to cut out a series of squares, all at the maximum allowed power of 85, and at different speeds. Depending on your material and its thickness, some of the squares might not cut all the way through because it was going too fast. So you want to select the square that cut out all the way through at the fastest speed. Note: Some squares will look like they cut through, and you'll be tempted to push them out gently when you take your test block out. Don't do this. If you have to push out a square, it was going to fast and you will get bad results. You want your squares to cleanly fall out under their own weight when you pull out the block. Even if a square falls through, you may want to go slightly (10-20%) slower than that speed setting to absolutely ensure your pieces fall out during your real project.
Step 4: Help Us Build a Materials Test Library
When you're done with your test block, add a label of the material type and thickness to the back of the block. Then place the block in our bin so others may learn from it!