Laser cutting: Acmer S1 settings by material

This post contains the settings (laser power and head speed) for cutting or engraving different materials using an Acmer S1 engraver eqquiped with a 3,5W (3500mW) laser head.

Note that, with slight or no tunning, the below settings should be applicable to different laser cutters.

Also note that, when necessary, the material brand (in italics) has been set (as for instance with the different masking sheets). Again, with slight or no tunning, the below settings should be valid for other brands.

Laser modes

The tables below define a parameter per row called "Laser Mode", that can take two different values:

• M3: Constant laser power mode. Usually set for cutting, the laser always work at the same power, no matter the path it is working on.
• M4: Dynamic laser power mode. Usually set for engraving, the laser power is automatically set depending on the path (slower on curves, faster on straight lines and corners).

You can find more information about laser modes in the GRBL wiki.

Cutting settings

The table below defines the settings for cutting different materials.

Note that, when dealing with adhesive sheets as a combination of an adhesive sheet plus a base sheet, cutting is intended as cutting the adhesive sheet without cutting the base sheet.

Material	Laser Mode	Head speed (mm/min)	3500mW laser power (%)	Laser power (mW)	Cycles
Yellow paper sheet	M4	900	30	1050	1
Hobby Mio masking sheet	M4	850	30	1050	1
Tamiya masking sheet	M4	950	30	1050	1
0,13mm white styrene sheet	M4	40	15	525	1
0,25mm black styrene sheet	M4	250	15	525	1
0,50mm black styrene sheet	M4	250	31	1085	1
1,50mm black styrene sheet (not optimal)	M4	250	31	1085	6
3mm black foam board	M3	300	60	2100	1
5mm black foam board	M3	300	67	2345	1

Engraving settings

The table below defines the settings for engraving different materials.

Material	Laser Mode	Head speed (mm/min)	3500mW laser power (%)	Laser power (mW)	Cycles
White styrene sheet	-	-	-	-	-
Black styrene sheet	M4	1000 750 500	20 15 10	700 525 350	1
Black foam board	M4	1500	30	1050	1

Material notes

White styrene

Engraving on white styrene (0,13 mm thick) has been impossible: the surface is both not altered by the laser beam or is cut. So below a threshold t1 the sheet is not altered, then between t1 and t2 the sheet is randomly cut or not altered and then above t2 the sheet is always cut, but engraving is never achieved. t2 settings are those defined in the section "Cutting settings" for the 0,13mm white styrene sheet.

To reduce the amplitude of the t1-t2 interval and therefore minimize the ramdom behaviour, the best is ensuring a good air flow during the process (laser diode fan running at high speed) together with wetting the base (preferably an aluminium plate base) where the styrene sheet lies. By wetting it, the sheet is in full contact with the base and the heat transfer from the sheet to the base is improved, reducing the heat in the sheet and improving the results.

In general, working with ws is not recommended. Though the availability of black styrene sheets is more limited, those existing black sheets (0,25, 0,51, 0,76, 1, 1,5 and 2mm thick) can be sanded to obtain the required thicknesses and then being cut/engraved with very good results.

0,13mm black styrene sheets

Up to date, there are not manufacturers offering 0,13mm black styrene sheets. Evergreen sells 0,13mm sheets but white, not black.

0,13mm black styrene sheets are the closer contender to 0,1mm photoetched brass products: Though not as bendable as brass, most of the brass parts can be done in styrene... if there were 0,13mm black sheets.

Until somebody out there manufactures these sheets, sanding a 0,25mm black sheet until getting a 0,10mm-0,15mm thick sheet is feasible. When working with accurate parts, as for instance 1:48 airplane rudder pedals, cutting them in 0,10mm-0,15mm sheets provides better quality than doing it in 0,25mm sheet, as thicker parts more difficult to bend.