Height of Laser to Work Surface

I’ve read the instructions where it says the distance from the laser to the work surface should be 5-10 cm.
Measuring mine as assembled it is only 2 cm. I’m curious about that . There is no way to adjust the laser head to accommodate those instructions.
So, I will use a block of wood to raise the entire laser assembly by at least 3 cm or about an inch and a half…! Does anyone agree with my accessment?

Welcome Doug! What machine do you have?

You want know the focus point of your laser, that is the point at which the beam is smallest. To do this you can set up an inclined piece of wood and do what’s called a ramp test. Do a line cut/etch from the low end of the wood to the high end. The place where the line is narrowest is your focus point.


That’s not unheard of to have to lift the entire machine to focus on these kits.

I’ve seen people 3D print an adjustable laser mount to resolve the issue.

Stock cheap K40 lasers (CO2) suffer the same issue, the bed is fixed. Most people add a moveable bed, weather it’s mechanical or stepper driven.

As NedMan says, do a ramp test and see where the focal point is (18mm for a lot of diode lasers). 5-10cm is a massive range, you would expect to be working to mm tolerances for the correct focus.


Diode lasers have an adjustable focus lens. You get the laser between 5 and 10cm of the work surface then focus the laser using the adjustable turning lens assembly to the smallest dot possible using the low power option on the laser diode. This process needs to be repeated every time you change the thickness of the substrate.


Mine doesn’t. Mine is fixed at 18mm.

But if some are, that does explain the 5-10cm specification.


Make’s sense

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