Bugs Can Be Anywhere

During class last night, we ran into a problem where parts of the user interface in Retina Engrave 3D were being disabled. The controls for setting raster power, for instance, were grayed out, and some (but not all!) of the menus at the top of the screen were also unresponsive.

It’s not too unusual for the laser software to get confused and need to be closed and restarted. That didn’t help. We tried closing and restarting CorelDraw, too, without success. We tried closing and restarting both at the same time. We even tried rebooting the computer. Nothing seemed to help.

Then Laura suggested power cycling the laser itself. That worked! We were all surprised, since it isn’t at all obvious that the laser software even talks to the laser before starting the job (beyond the connection monitor in the lower left corner, that is), but apparently it does.

So, when things go off the rails in a bizarre way, don’t forget to try power cycling the laser.

Print Scale Factor

During class last night, it seemed like everything we printed was coming out a bit bigger than we intended. After class I tracked this down to a setting in the CorelDraw print dialog. On the Layout tab, you can control “Image position and size” for the print. By default, it is set to “As in document”, so what you drew is what you get. You can also choose “Fit to page” or “Reposition images to”, and with the latter setting, you can set a scale factor, or even separate scale factors for horizontal and vertical. Somehow the scale factor got set to 1.16, which makes everything print 16% bigger than drawn.

This is a useful feature to know about. But please, if you use a feature like this, try to remember to set it back to the default before you go, to avoid causing problems for the next user.

Two Inkscape Quirks

Recently Jon ran into two problems printing to Retina Engrave 3D from Inkscape. We don’t understand all the ins and outs, but there would appear to be some bugs somewhere. I’ll describe the symptoms and the workarounds we found. Maybe that will be helpful if you happen to run into similar problems.

Problem 1 manifested as missing vector objects. That is, some of the stuff that was drawn in Inkscape mysteriously didn’t make it onto RE3D’s vector screen. What we found was that one of the vectors had been drawn with partial transparency. That is, its A (alpha) setting on the Stroke Paint tab of the Fill and Stroke palette was set to a value other than 255. Apparently this made that vector block out other objects in its vicinity from being printed.

Problem 2 was that the raster screen in RE3D only showed part of the drawing. In this instance, a yellow vector rectangle had been drawn around the entire drawing with the express purpose of forcing the raster and vector screens to have the same extent (a useful trick that allows you to print subsets of your drawing and keep everything in perfect alignment). However, the vector rectangle was being ignored for raster purposes, even though it showed up on the vector screen. A workaround for this was to fill the rectangle with yellow, and move it all the way to the back of the drawing so it didn’t interfere with any of the other raster data.

So, if you use Inkscape:

  1. Don’t use transparency in drawings for the laser, and
  2. Fill objects you need to see on the raster screen.

Class scheduled for Tuesday, September 29th

Another session of the basic operation and safety training class has been scheduled for Tuesday, September 29, starting at 6:30pm. The class is free, and once you’ve completed the class you’ll be eligible to sign up for time on the laser, which is also free for art and personal projects.

The class starts with 90 minutes or so of classroom instruction, which is followed by practical hands-on exercises in the laser room. The laser room is small, so enrollment is strictly limited. Email class@colaser.org to sign up for your spot in the class.

This will very likely be the last class before YOUtopia, so if you have a project in mind for the regional event, this class is for you!