How to print to scale...

June 25, 2019 8:51 AM

So I think this is probably something I could Google for, but so far, my Googling has let me down! I can find a thousand and one tutorials and forum posts for similar topics but not for this use case: This happened last week: I made a Sketchup model of something I wanted to have laser printed. I converted to a Coreldraw format because that's the format my laser printer wanted it in. In so doing, the scale was lost. The drawing got blown up. I wanted to rescale the entire document, using a known measurement on the drawing as a reference. I couldn't for the life of me figure out how to do this!

I'm sure it's something I've done before, I've just forgotten the 'trick' and which measurements are needed for the calculation to work.

Any help much appreciated!

TLDR, how to use (for example) a rectangle on your drawing that you KNOW needs to end up as a 14mm x 14mm cut out, to figure out by how much the entire file needs scaling up or down to suit.

posted by dance to Computers & Internet (6 answers total)

Best answer: If you have a rectangle that you know should be 14mm x 14mm, and you highlight it in Corel Draw and the Dimensions readout says, for example, 75mm x 75mm, then you want to scale it by

14 / 75 = 0.1867

Multiply that by 100 to get percents, and you've got 18.67% scale.
posted by moonmilk at 8:55 AM on June 25, 2019

I don't know what your laser cutter software is like but this happens all the time with mine. I select the whole dang thing in my design software, look at the dimensions of it, then do the same in the laser software, and resize the whole dang thing to the right size, with maintain-aspect-ratio clicked so I only have to type in one dimension.
posted by aubilenon at 9:04 AM on June 25, 2019

I don't know this particular software, but in addition to the above, it's also worth noting that some software will choose to automatically scale the output to the size of your drawing rather than the size of a page. Framing your drawing with an L made of lines (better yet, lines with tick marks you can measure with a ruler) that's bigger than anything you might want to draw is a crude way to avoid this and insure you always get the same scaling for multiple parts.
posted by eotvos at 9:05 AM on June 25, 2019 [1 favorite]

From SketchUp, export to a PDF, DXF or DWG with a known scale, then import, and try in that program printing to a normal paper printer first and measure the distances.

Edit: The basic SketchUp file is in units of Inches, so you might consider sizing it down by 12x if your image editor is dealing in feet.
posted by nickggully at 12:02 PM on June 25, 2019

Best answer: There's always Matthias Wandel's Bigprint. It prints 1:1 from images.
posted by sydnius at 12:36 PM on June 25, 2019

Does your version of Sketchup have Layout? You can import your model and print to true scale from that program, which is bundled with my install.
posted by a halcyon day at 12:51 PM on June 25, 2019