Solved: 3DS Max export to STL with wrong unit/scaling

Anonymous · ‎08-17-2016

Hi, Here is my question, background, context and settings hereunder: How can I export an STL object which keeps its same dimension as in 3DS max ?!? Context and background: I am trying to create models that I can print with my local fablab. I am using 3DS Max 2015 and exporting files to .STL. According to fablab I need to use "ascii" export and not "binary", however I did try both but with the same result: 1) I only have ONE object. 2) 3DS is set to use mm: unit setup > metric > millimeters 3) The object dimensions (in mm as shown in 3DS): 232x85x8 4) The STL check modifier in 3DS tells me there are no errors. 5) I export the object: 3DS > export > .STL (a window pops up with very few settings) > object name: Object01 > ASCII > Selected only > OK Note that I also tried to use a different name than Object01? I tried ASCII then BINARY. I tried to tick and untick "selected only". However every thing leads to the same conclusion. 6) When I import the file with netfabb the object's dimension is: 9,13mm x 3,35mm x 0x31mm When I import the file with netfabb the object's dimension is: 9,13mm x 3,35mm x 0x31mm Now the funny thing, if I set 3DS up with: customize > unit setup > US standard > decimal inches. I notice that the object dimension are 9.13 x 3.35 x 0.31. Which is the size of my object IN mesh mixer and IN netfabb, only with mm instead of inches... Some coder ****ed it up somewhere. I have seen numerous post on forums with people struggling to export STL files and "keeping" the dimensions. I am speaking about different softwares here. However I could not find any good resource on the subject for 3DS max and I am CERTAIN that some people wanted to create models to 3D print afterwards and struggled with the STL export as me :(. I could **not** transpose any solutions given in these post as they refer to some settings that have to be configured within the STL export plug in. 3DS STL export plug in only has the settings that I listed above. I also tried changing the units of 3DS. Same result :(. Please help meeeeee I am going crazy. Yours, --Jay

Alfred.DeFlaminis · ‎08-19-2016

Hello @Anonymous,

I'd would love to help you with this, and if it helps retain sanity even better! 3d printing is fun stuff, but so technical! The good news is some coder didn't mess up, it's likely just a system unit issue. My guess is your system units are set to inches, but your display units are set to mm.

First, I want to make sure you are describing your system units or your display units. Can you verify that for me please? I have a screenshot below to help illustrate what I mean.

Keep in mind that when you change your system units from inches to mm, you'll have to rescale the model in some cases, and reset the Xform afterwards. If I am incorrect, please let me know and we'll keep going! However, this is the most likely cause of this and the thing that trips people up quite often.

Please hit the "Accept as Solution" button if my post fully solves your issue or answers your question. This lets me know that I was effective in helping you, and thank you for doing so.

Best Regards,

Anonymous · ‎08-19-2016

Hey Alfred, TL;DR: You are officially a God to me that I would cherish and love till the end of days and mankind. Complicated version as it might help other people: I had no idea there were two units system in 3DS (hard to make any sense of this concept tbh), one for the screen, and one for, well... I don't even know, but there's definitely a second one... : P. (On another note, why "inch", "feet", and "yards" and other **** like this still even exist in our universe even though they don't make any sense whatsoever?! Hugest troll story in history if you ask me....). There was 2 DIFFERENTS ways that would 'solve' my issue, meaning to have the model in netfabb/meshmixer have the correct dimensions. A) Brute force solution: The issue was solved if I did not change anything regarding units/unit system in 3DS but scaled EVERY MODEL UP by 254% (Because 1inch = 254mm and as everything was tiny it felt like the right call to make to make everything bigger by 254%). B) The other fix that I applied (partly random because I was just testing actully, but still using my new acquired knowledge thanks to you): 1) Create a new file. 2) > Customize > Unit Setup > Metric > Millimeters. 3) > Customize > System Unit Setup > 1 unit = 1,0 mm ("respect system unit in files" TICKED) THEN I opened again my ORIGINAL file and 3DS poped up a window. See screenshot. This window was setup exactly as in the screenshot. I left everything as is and clicked OK. The my ORIGINAL scene finished loading. The dimension of any object that I exported using this "new" scene was coherent, meaning the "object properties dimensions" in 3DS MATCHED the dimension in netfabb or even in meshmixer (which makes sense according to what's written in this pop up window. From what I could understand then, it *should've solved* my issue, and it did, and I did NOT have to scale anything using this method as 3DS converted everything). Every day a little smarter... Yours, --Jay

Alfred.DeFlaminis · ‎08-19-2016

Aw shucks @Anonymous, you're gonna give me an ego.

From the sound of it, you have a bright future ahead of you. Best of luck on the printing and don't forget to show off all your cool stuff in the Gallery! Thanks for the update and I'm glad it worked out for you!

I'm not really sure why we still use Imperial units. Stubbornness I guess...

"My car gets forty rods to the hogshead and that's the way I likes it." -Grandpa Simpson

Anonymous · ‎01-04-2019

you just saved my life thank you mate

Anonymous · ‎07-28-2019

False. I tried the same procedure. It failed.

kevin.evans.101 · ‎12-09-2020

The same issue as this original post, however, the solution suggested doesn't work for me.

My system unit settings are in inches and my display unit scale is US Standard. The issue is, my .stl output from 3DS is in mm which causes issues when I import into my 3d printing software. My software gives 3 options: import as is, scale in mm, and scale in inches. Every choice gives the same result which is in mm.

As the original post, I've check and changed each .stl setting and I'm getting the same bad results.

Any suggestions will be promptly tried as I need this 3d print quickly.

Thank you in advance!

kevin.evans.101 · ‎04-13-2021

My system unit settings are in inches and my display unit scale is US Standard. The issue is, my .stl output from 3DS is in mm which causes issues when I import into my 3d printing software. My software gives 3 options: import as is, scale in mm, and scale in inches. Every choice gives the same result which is in mm.