MakeBlock LaserBot laser engraver/cutter- first impressions

This week, we have received a LaserBot unit, a simple laser engraver/cutter manufactured by MakeBlock. With ~350 USD is not the cheapest on the market (ask ebay for lower-power solutions), but it looked sturdy with a 1.6W LED laser and as MakeBlock offers a rich ecosystem of additional hardware options, it seemed a good start into laser-engraving with additional hacks in mind.

After ordering, LaserBot arrived a after few days at our place in a nice box with a parts list an a link to a video tutorial for putting it together - very well made, if you step through and pay attention to the details and numerous notes, the device is quickly assembled, and despite a slightly damaged beam it looks sturdy.

I tried to print a few files with the mLaser software, the results looked fine at first glance - the "M" logo and scales printed perfectly, but if you're trying to do serious work (pcb solder stencils and other scale-relevant work) important things like scaling do not work:

As a first test, I downloaded a Hilbert curve from Wikipedia (the bottom right iteration) and printed it; the mechanics worked fine, but the file scaled to 3.5x3.5 cm - while the pattern has 10x10cm footprint.

There is a scaling dialog that lets you zoom into pictures for engraving them, and this should work for SVG graphs as well, but as it is based on the SVG viewport and not the graphics size this is hard to extrapolate.

Even worse, it seems that parts of vector graphics get lost - the PCB stencil that I used for tests should cut out a number of rectangles, but random sections have not been lasered.

I've posted a request on the MakeBlock forum, let's see if we can improve on this.