Is it possible to resize an object setting a segment length?

LightBurn Software Questions
1

Hello!
I’ve made this desing in my favourite CAD software and exported it to DXF:

image
image1301×519 46.4 KB

When I import it on LightBurn, the dimensions are wrong (I’m working in mm in both softwares)

Is it possible to tell LightBurn to resize the object using the 5mm line in the middle, for example?

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I can’t find any tool for this. What I do is to make a square of 5mm and adjust it visually. But it’s not perfect…

It would be awesome if LightBurn had a dimesion tool, then click on a line/segment, set it’s length and it changes the size of the object accordingly,

Thanks.

2

I’ve found how to export the DXF so it imports with the correct dimesions.
But I still have the question above, thanks!!

How to export correctly from onshape:
image

1 Like
3

Go to Edit->Settings->File Settings and pick millimeters for your DXF import settings. You may need to disable the “Auto-detect settings” if it doesn’t work with that setting.

The easiest way to do this:

  1. if you know the actual dimensions of the whole shape than just resize the shape to that dimension with the aspect ratio locked
  2. if you want to use your method of resizing against a known segment length then:
    2a. create a 5 mm long line
    2b. move one end of the current line segment on top of one end of the 5mm long segment
    2c. use Arrange->2-point arrange scale. Click on end of shape used in 2b. Then click-hold on other end of line segment. Hold shift while you move the mouse pointer to the other end of the 5mm long segment. Release mouse.
4

Thanks! I have really tried but I don’t understand 2b and 2c steps, sorry…
Video of me failling to follow your steps: https://amaroa.es/help/sizing.mp4 (sorry, contextual menus were not recorded)

5

I realized it’s hard to see what’s happening if both lines are perfectly horizontal. Here’s an example with the reference segment rotated.

rotate-scale

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6

Thanks! I’ve marked as solution. Still would be awesome if they could add the “dimension tool”
image

7

If you know the desired segment length (5mm) and you measure 127mm… can’t you just find the scale factor 0.0393 (5mm/127mm), select all shapes you need scaled, lock the height and width dimensions, and multiply either one (height or width) by the scale factor?

I’ve often done that with slotted designs to adjust for the material thickness I want to use… and it seems to work fine.

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8

Further to David’s note, this math can be done in the height/width box. Lock the aspect ratio, select everything you need to resize and then in the case of your example above, add “*(5/127)” to the end of one of the current dimensions and hit enter.

2 Likes
9

Yep. That’s actually the way I do it… saves pulling up the calculator. :wink:

10

This is so simple and so clever I’m mad I didn’t think of it… THANKS!

1 Like
11

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