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Henryhbk
(@henryhbk)
Estimable Member
how to scale models?

Alright, I may be going insane (or have always been so?) anyway, I have some CAD models I am making for a diorama. For ease of modeling I did the CAD model life size, figuring no problem, just scale down to the 1/35 scale of the model I am making (i.e.1/35 =  0.028571428571429 per my calculator). When I import it into prusaslicer 2.6 it auto-scales (yeah, it's huge compared to the printer) and then to make my math work, return it to 100% scale, and apply that decimal above, which prusaslicer rounds to 0.03. Fine, except the model is way, way to small (pretty sure below the capability of the mk4 if I somehow wanted it that tiny). Here is a shot with the scale factor applied... (that model is about 2m tall and 50cm thick in real life (it's in inches in CAD but just estimating). Am I doing this wrong (I can also work off dimensions to scale it, as I have one of these already in the real size I guess)

Posted : 19/07/2023 12:12 pm
Neophyl
(@neophyl)
Illustrious Member
RE:

By default PS uses mm.  Are you set up in mm or inches ?  Natively its all metric so probably best to use that if you can.

Posted : 19/07/2023 12:20 pm
Chris Hill
(@chris-hill)
Estimable Member
RE: how to scale models?

If the numbers in your STL represent inches, and PrusaSlicer interprets them as mm, you'll just need to scale everything up by 25.4.

Posted : 19/07/2023 12:45 pm
karl-herbert
(@karl-herbert)
Illustrious Member
RE:

Usually you can set the export to mm or inch for all CAD systems. PS import is set to mm by default.

wbr,

Karl

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.

Posted : 19/07/2023 12:58 pm
Henryhbk
(@henryhbk)
Estimable Member
Topic starter answered:
RE: how to scale models?

thanks for everyone's input. Yes, I had set the output of OnShape to put out mm, although if i recall prusaslicer detects that and auto-converts., But either way, the model seems way smaller than the scale factor should make it (scaling should work either way

see attached image for the unscaled import (regardless of units) - note  the print bed in the screenshot for scale

Posted : 19/07/2023 1:10 pm
Henryhbk
(@henryhbk)
Estimable Member
Topic starter answered:
RE: how to scale models?

OMG, I am such a an idiot. Gotta get more coffee, it's already a percentage not the decimal factor. Duh, so my scale was 2 decimal places off... 🙄 so it should be ~ 2.85 not 0.0285. none of you saw anything!

Posted : 19/07/2023 1:23 pm
Chris Hill
(@chris-hill)
Estimable Member
RE: how to scale models?

Er, yeah, we all saw that of course, but between us we agreed you'd learn best by finding out for yourself.  Ahem. 🙂

Seriously though, I've made the same mistake myself!

Posted : 19/07/2023 1:42 pm
Henryhbk liked
Henryhbk
(@henryhbk)
Estimable Member
Topic starter answered:
RE: how to scale models?

As I always tell my nurses, if you ever see me not drinking coffee, call a code-blue, I've probably died. During the pandemic when we weren't allowed to unmask at all in the hospital, I had a camelback with espresso that snaked under my mask (yes, 2L of espresso)

Posted : 19/07/2023 1:46 pm
karl-herbert
(@karl-herbert)
Illustrious Member
RE: how to scale models?

wbr,

Karl

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.

Posted : 19/07/2023 2:36 pm
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