Cutting depth... Cutting through a book

Hi brain trust,
I’m slowly-slowly working my way through the features of my A150 to the point where I’m still testing out the Laser module. I have had success with…

  • timber (a few different types)
  • cardboard
  • leather
  • bamboo
  • and most recently, painted/engravable hip flasks

The only paper I have cut is the camera calibration but I want to cut through the pages in a book.

I’d like to “Shawshank” a book to conceal a hip flask. I figured a laser would be a neat way to cut the precise shape to fit the flask.
My concern is cutting depth. My snapmaker tells me that my “laser height” is 28mm but as I have observed the gap between the tool head and the material is less that 28mm I assume the 28mm does not include the “guard” but refers to the laser output up inside the “guard”.
I plan to do some of my own testing but I don’t want to bottom out the laser module. What is the maximum passes/z-step I should try?
The maximum values accepted by Luban are 50 passes with a z-step of 10mm which is an overall distance of 50cm, more than 3 times the capable height of the machine so no help there.

My assumptions:

  • I could measure with my vernier, the distance between the tool head and the material at the work origin and step down to less than that value.
  • The actual depth of cut from repeated passes will likely be much deeper as it is paper afterall.
  • I might see it catch fire.

Any advice or theories are welcome.

I’ve done that with a handheld router. I don’t see the laser succeeding in that unless you do it page by page.

It could probably be CNC cut. Make a jig to clamp the pages.

Cheers. Might give that a try when I get to the CNC tool head. I would have thought it would chew up the paper given the rotation.
I’m going to try it with the laser anyway, just wondered if anyone else here has done something similar.

I think you’re looking at this wrong. There is not a specific cutting depth with the laser. It’s a beam that has a particular focus point (beam waist) wear the beam is narrowest and the power is most concentrated and the cutting is optimal.
As it gets wider it loses power and preciseness. So depending on the material it still may cut or just char (or possibly ignite the material and set it on fire).
What I would do is figure out how many pages you can cut through cleanly (with however many passes) and then use something as a shield for the pages below it. A piece of thin plywood would probably work just fine.
As far as focus goes the ‘laser height’ is from the top of the workpiece to the laser lens. It varies slightly for each laser head. With the lens hood it’s usually somewhere between 5-10mm of clearance. The lens hood can be removed to give more clearance for multiple pass heights.


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That’s actually precisely how I am looking at it.
If I want to cut at the focal point I need to lower the laser the deeper I go and therefore, theoretically I would have to pause the cut, fold back some pages and recommence. In this same scenario I assume I would only be able to cut as deep as the distance between the hood and the paper before having to fold back pages and start again.
However, as I alluded to and as you have stated above, as I cut away paper and the distance between the laser and the material extends, the beam will widen… but will likely still cut… but may start a fire.
I can’t find anything online suggesting anyone else has tried this so I was planning to just set it up and see what happens. I can always pause and inspect at any point if something doesn’t look right.
Thanks for your reply, I’ll post my findings after the test… provided my workshop doesn’t burn down :wink: