Cura 4 generates a mirror image

[CharlieWorton 0]

I've encountered the strangest problem ever.  I generated a small cap for an accessory lens I own, and I labelled the cap with the phrase '2X Barlow Lens' using the text function in 123Design (Yeah, I know.  I haven't switched over yet.)  The cap printed fine, but the text was completely reversed - a mirror image.  I found the option to generate a mirror image of the .STL file in Cura (4th screen button down on the left hand side) and when I clicked that, I was able to duplicate on screen what had actually printed.  I now have a print of that reversed image coming off the printer.

 

But... what the heck?  Is there some setting in the printer setup file I might have messed up?  Has anyone else had this problem?  It just seems so bizarre, that the printer will spring to life, and generate a perfect, exact mirror image of what I asked it to print.  Thanks for any help you can provide... >Charlie

[gr5 1,335]

What kind of printer is it?

 

Cura expects 0,0 to be in the front left corner.  If either your Y or your X axis is backwards then it will print a mirror image.

[CharlieWorton 0]

Hi, GR5!  The printer is a Chinese Zonestar printer, essentially a stainless steel frame Prusa design.  Software is (I believe) Marlin, running on a Melzi board.  Here's a link: https://www.aliexpress.com/item/Upgraded-Quality-High-Precision-Reprap-Prusa-i3-3d-Printer-DIY-kit-with-2-Rolls-Filament-free/32342171432.html 

This link shows the current model; mine is about 2 years old, and has the older Melzi board.

 

The strange thing is, it worked fine for quite a while, and has only started to print backwards in the last 6 months or so.  (I don't use it a lot.)  So, in the beginning, it did work well, which leads me to believe that I've inadvertently set a switch to the wrong setting.  I can't imagine a hardware failure causing this.

 

BTW, the reversed print printed properly.  So, somewhere in the slicer or the printer, a horizontal mirror image is being asked for and created.  I just have no clue how this might have happened.  Thanks for your help!  >Charlie