Laserleikkuri CM1690

Laser engraver CM1690

The Machine

Quote: "Laser Cutting Machine work with Co2 Laser, it is used for cutting wooden plate, acrylic, paper, plastic, rubber and other no-metal materials for complex shape. Laser Cutter is useful in many products such as air plane model, advertisement, decoration, article gifts, toys, and face guard of machine. Laser Cutting Machine and Laser Cutter is designed for industry application, driven by high-grade stepper motor, precision guide way drive and High-precision in positioning make the running more stable, Large area precision cutting mechanical movement system can guarantee smoothness and flatness of cut cross section."

• Working Area (mm) 900 x 1600
• Max speed 1000 mm/s
• Resolution 2500 DPI
• Repeatability 0.01 mm
• Accessories: Air assist, Air extractor system, Water cooling system

First rules

Unclean mirror looks like this

• Only operated by qualified operators, trainings will be organized with some regularity
  • Operators must properly fill the logbook
• Lifting the honeycomb must not be done alone (it's easy to break and costs 1800EUR to replace)
  • You probably don't need it anyway unless you're doing tiny things or fabrics.
• Never leave machine unattended even for a moment when it is cutting (significant risk of fire)
• Never touch the laser lens/nozzle combo.
• Use only pure distilled water (akkuvesi) as cooling water, do not add anything else to the cooling water.
• Since the Laser-SW requires admin rights we must allow admin logins (bad but unavoidable), this means this machine will not be used for general purpose anything and only the superusers are allowed to install anything (sw, browser extensions, anything) on it or adjust adblocker/noscript settings.
  • We also highly recommend minimizing internet use on the machine. Use another computer for finding your designs etc. from the internet and then move the files with an USB memory stick instead, just to reduce risk of malware infections due to unscrupulous advertisers etc.

In case of fire

• Small fire: open lid, try to blow it out.
• If fire does not go out with blowing, use the fire-blanket.
• If blanket does not solve the issue use the CO2 extinguisher, leave the room, close the door and inform everyone at the lab. Email the board asap.
• If the CO2 extinguisher did not solve the issue: evacuate lab, call fire brigade, inform the board.

Specifications

• Cutting area: 1600 × 900 mm with through feed.
• SW used: Autolaser
• File formats:
  • Adobe Illustrator
  • DXF (R12 works best)
  • BMP/JPG/PNG, can be loaded directly, but can only be used for engraving.
  • "ISO" Gerber
  • SVG is NOT SUPPORTED.

Laser Focus Lens

• PVD ZnSe coated Lens (coating 10µm)
• Diameter (Dia) 20 mm
• Focal Lenght (FL) 63.5 µm
• Concave side down

Notes on DXF files

• DXF produced by Fusion 360 has problems with splines (according to the internet, Fusion uses 5th degree splines and most laser programs support 3rd degree at most. Fusion 360 has a plugin by autodesk that saves DXF as polylines and it appears to work really well [1])
• There is a plugin for Fusion 360 called DXF for Laser, which takes a face and produces a clean DXF (without construction lines) and allows adjustment of the borders to account for the laser cut width. This has been used successfully with out laser.
• Inkscape can be used to create paths / vectorize bitmaps / convert SVG / etc. You must use "Break Apart" feature to split paths to line segments and then save as DXF.

Notes on raster files (carving)

• Autolaser produces only 1-bit carving. This means that laser is only either on or off with selected power and speed, nothing in between.
• If you need different carve settings (depth, darkness), you have to export all different shades as different images and import separately.
• Autolaser can generate dithering or raster effect for grayscale. Click on bmp-button on the toolbar to see possibilities. The result is not great, your image editor of choice probably does better job.
• Minimum laser power seems to be 9%, laser won't light at all below this. 10% seems to be a bit more reliable than 9%. You can reduce the strength of carving by increasing speed. 1000m/s still seems to work quite reliably.

Materials

Basically everything except metals and stuff that produces poisonous/corrosive gas. Why not metal? Short answer: Metal reflects IR too well to be cut with IR laser. Marking metals is possible, though.

• See http://atxhackerspace.org/wiki/Laser_Cutter_Materials
• https://wiki.tampere.hacklab.fi/tyokaluja/laserleikkuri

Below you'll find some notes on materials that have been tested.

Basic Plywood

Not recommended for use with the laser. Use interior plywood instead (see below). Basic plywood from the hardware store. The layers are glued with dark glue ("fenolihartsi"). Can be cut with the laser but the cut edges will be very dark and sooty. The sooty edges require a lot of messy post-processing, and the extra smoke in the machine dirties the mirror quicker.

Can be bought almost every hardware store with drive-in-hall, eg. K-rauta, Bauhaus etc.

3mm wont cut thru with 90% 25mm/s single pass, 2 pass ok.

For 1 mm plywood, values for cutting saved on the laser computer worked well.

Interior Plywood

Better for laser cutting. No dark glue between the wood layers. Keywords to find the right stuff: "Urealiimattu" (ureaformaldehydipohjainen liima) vaneri (EN 314-2, luokka 1, interior; e.g. UPM Wisa Interior).

Where to buy:

• Very thin birch plywood (0.4 mm to 2.5 mm) can be found in 30 x 30 cm pieces from Hobby-Point (shop in Kamppi). They're very expensive, at ~8€ per piece. It cuts very well.
• Full boards can be found from Lahti, http://www.murtoraja.com/vaneri 152x152 4mm 50 euros, price can vary.
• Plywood and veneer available from Mahogany.
• From Hacklab's plywood store, using MobilePay

Prices for interior plywood at the lab

Note that the plywood sheets at the Hacklab can only be purched using MobilePay.

Thickness	1 sheet	1/2 sheet	1/4 sheet
8mm	16€	10€	6€
6mm	15€	10€	5€
4mm	14€	8€	4€
3mm	12€	7€	4€

Settings

• Cut 90%, 25mm/s single pass was good cut for 3mm.
• Carve 10%, 1000mm/s produced nice, print-like result in milk coffee color
• Carve 20%, 1000mm/s produced a shallow carving in dark coffee color

Acrylic

• Etra Megacenter Suutarila

• Leftover pieces, various thicknesses (have seen at least 2, 3 and 4mm clear some white) 8e / kg
• Full boards 40-190€ / m2, 10€ for sawing

• muovia.fi

• Leftover pieces, priced by size. Many different materials, thickness and colors, but mostly clear.

Settings

• Cut with 2 passes on 90%, 25mm/s cut through 4mm acrylic. The cut edge was nice and smooth
• Carve 30%, 300 mm/s produced pretty deep result. Removing the protective plastic improved accuracy

POM / POM-C

• The sturdiest material to cut for machine parts

• Tjl is setting up a stash that will be open to use, see POM-stash

A Nintendo DSi Console

• Unknown material, maybe polycarbonate?
• Carve 10%, 1000mm/s, horizontal unidirection produced classy looking "print".
• Plastic seemed to need time to cool between carvings and unidirection helped with that. Bidirectional carving produced ugly bubbles.
• Clean the surface throughly before carving
• Remove battery out of caution
• Example result photo

"Messumatto"

• 30% 20mm/s cuts nicely, beware of versions with plastic coating.

Operating instructions

Start of operation checklist

• Open the log form, fill in your name and the current time.
  • There is also link on the desktop of the computer.
• Get keys from their defined storage location.
• Check log entries for when the water was last replaced, if it was over 4 weeks ago, replace water (again: only distilled water with no additives). Email the board to let them know that more water is needed.
• If you did not replace water: Check log entries for when the water level was last checked, if it was not already done today, check level and add water if needed. Take care not to let any contaminants in when checking or adding. If water can be seen, its ok. Mark in log accordingly.
• Make sure the honeycomb is not installed (when the machine resets it will raise the bed, if the honeycomb is on this will lead it it crash into the cutting-head)
• Use keys to turn on power
• Turn on blower (switch)
• Adjust bed for correct focus distance for your material

Cutting checklist

• Did you change material? If yes, re-check focus distance
• Adjust head position, set origin (NOTE: the red helper dot might not be pointing exactly to the cutting point, use "pulse" to verify)
  • Make sure you know which point of your cutting job you should set as origin in the machine.
• Use "border view" (sw) or "range" (panel) to verify bounding-box of cut.
  • DON'T enable "idemitsu" flag. This will turn on the cutting laser during the border view, even if the lid is open
• Make sure blower is on (switch)
• Make sure lid is closed
• Start cutting, keep close watch on what is happening.
  • Risk of fire
  • Settings may need tuning
• When done cutting wait 30-60 seconds for fume extraction before opening lid.

End of operation checklist

• Remove honeycomb if installed
• Raise bed to top
• Turn off blower (switch)
• Fill uptime, laser on time & work time to log
• Turn off machine (keys)
• Clean up the bottom "drop area" in case you dropped something.
• Finish filling up the log form (notes, end time) and submit.
  • Failure to submit logbook will result in suspension of "qualified operator" -status.
• Put the computer to sleep or just leave it to go to sleep by itself, do not shutdown it completely.
• Return keys to their defined storage location.

Detailed laser cutter instructions (Instructions in progress)

Superusers

• Aaro
• Kremmen
• Suovula
• Rambo

Useful links

• Laser cutter cut width and inaccuracies (Wandel)