Scale a part from an nc or stl

What’s best practice for scaling an nc file or an stl file? There’s this small part for which the designer has provided an nc file and an stl file. The part is 1 inch x 1 inch and I want it 2.5 x 2.5.

The quickest way I have found is to import the stl into Tinkercad, where you can resize when it imports. Export that back out as another STL. In Fusion 360, open a mesh and select the stl. Change that into a brep and then go into CAM and do the CAM work there. Both the Fusion 360 simulator and CAMotics shows that it should work, but I haven’t had the chance yet to run it on the S03.

This could be one of those things where I’m missing the obvious,

nc is the file extension estlcam uses for it’s cutting files. but it also has a scale command in the other part (cad?) where you “open” an stl file… I haven’t used an stl file yet, but the scale command should be there,… everything else is easier in estlcam maybe this is too… good luck.

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Best practice is likely in the eye of the one needing to scale and the available tools… I’ve not heard of a G-code scaling utility, but it should be doable? I’ve done some rudimentary scaling of STL in Estlcam, but the projects were play. Scaling of DXF or SVG imports is also very easy in Estlcam.

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There are a couple of G-code scaling utilities listed at:

You can import stl directly into fusion360 now. Scaling the gcode itself is going to introduce a bunch of errors I think - endpoints aren’t going to necessarily line up properly when a sub-tolerence difference gets scaled.

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Yes, importing it to the web interface and then double-clicking it to open in F350 works. Thanks for the tip. I can’t find a way to scale in F360, so I guess that has to be done elsewhere first.

I agree that scaling an stl or an nc is fraught with problems and I wouldn’t do it if I needed something accurate. What I want to do is take the bit fan from TheOtherMachine and change it from 1 inch diameter to 2.5 inches. Why? Because I don’t have a 1/16 inch bit that the bitfan stl uses. My smallest is a 1/8 and I just want to do this for testing, so I’m using what I have on hand.

I was wrong. You can import and scale an stl file in Fusion 360.

A little later: If you upload an stl to the cloud and open it in F360 by double-clicking, it will be 10 times the size of the original. That’s because F360 is designed around centimeters. So saving an stl to the cloud is not recommended. If you Insert Mesh and grab an STL and set the units to mm (or whatever the STL was designed in), you will get the correct measurement. You can do a Modify | Scale of an STL but you have to first turn off Capture Design History.

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