Lasercutter - Setting and Examples

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Saved by Gavin Smith
on June 14, 2011 at 12:49:40 pm

Using the lasercutter is a bit of a trial and error process, so it's important to record any settings and tricks you came across. Plus it's always good to show off your new toys. With that in mind, here's a page for anyone to stick up photos and descriptions of what they've made.

Material Power Samples:

I cut a few objects at various settings so people get a feel for what it's like. Must emphasise that this isn't a hard-and-fast rule. How long since the lasercutter's been cleaned (mirrors smoked up), alignment, maybe weird stuff like water content of materials, etc. are going to change how much power to use. This should reduce the amount of trial-and-error required, though.

The brushed aluminium I'm particularly pleased with. The engrave didn't come out too well, but the vector cuts (2-4th line) are beautiful. This photo was taken after giving it a thorough scrub with a rag and water, and the marking is very robust.

Box-o-Tron Example:

Power: Engrave @ 20%, Cut @45%. Material is 3mm clear acrylic.

The Box-O-Tron script is a really fast way to make enclosures of any dimension. You can choose between Makerbot style with bolts, or more simple tab and slot construction.

http://www.thingiverse.com/thing:404

If you're making any sort of project that uses a case, it's invaluable. Once it's created the DXF file, you can then edit it and add in cutouts for switches, LCDs, text for buttons, etc.

One small nitpick. The script likes to put an extra rectangle around the edge of each part. I deleted it manually, since that would mean the lasercutter would cut it twice.

Sample Glued Boxes:

Power: Engrave @ 20%, Cut @45%. Material is 3mm clear acrylic.

(The exact command used to make this design was './boxotron.py -l 50 -w 50 -d 50 --type slot -f box2.dxf' )

We've got a couple of different types of acrylic glue in the space. The first is a waterthin liquid dispensed from a needle squeeze bottle (I think it's a generic version of 'acribond 110'), and the second is a thick goop known as 'IPS Weldon #16'.

The thick stuff is great for when edges are uneven, but it's hard to handle and I generally end up making a mess. The thin stuff is a godsend to use. All you do is hold the box together and gently run the needle down the join. A really thin trickle of glue comes out and wicks into the area between the plastic. Hold it for a couple of minutes and it's ready to stand on its own. 24 hours later the join is cured completely and strong as an ox.

There's some more information on how to use the two types of acrylic glue here, and they put my technique to shame:

http://www.youtube.com/watch?v=hT6Ow_cBTps

Hole Gauge:

Power: Engrave @ 20%, Cut @45%. Material is 3mm clear acrylic.

This was derived from this part on Thingiverse. Very handy for knowing exactly how large a hole is produced for a given input size. In most cases the laser thickness ('kerf') is negligible, but it's good to check.

http://www.thingiverse.com/thing:2073

There was a bit of fiddling needed to get the DXF imported into NewlyDraw succesfully. The trick was to select everything and do Object-->'Convert to Path', before exporting.

This gives a perfect example of the speed that the lasercutter operates at. The text on the front is raster engraved. (the head zooms back and forth), whereas the holes are vector cut. However the text engraving took the most time as the newlydraw software had to sweep out the entire area, even the blank bits.

Total time: 34:30sec. (estimated)

Time to cut all the holes 2:30sec. (estimated)

So the lesson is to keep engraving to a minimum to speed up your times. Alternatively we could have done the engraves one at a time, minimizing the raster dead space, but that would have been trickier to set up and align.

R3becca's Brass (Acrylic) Knuckles:

After a few prototypes in ~3mm acrylic I pushed Robots and Dinosaurs new laser cutter to it's limits with a custom design cut into 20mm acrylic. Many many passes of the laser along the same path were required but eventually it cut through. This creation was purely to experiment with thick acrylic and gain experience with the design process when using the laser cutter. This object will not be sold or used in anger, ie; it's art. :)