3D Builder weird scaling issue in metric vs imperial

First of all, good to know that this forum exists. I was an avid user of sevenforums for support and troubleshooting, much better than MS support forums by far

Actually, I posted the same question/problem there, so I just copy and paste here:

https://answers.microsoft.com/en-us/...6-e4355b1248c5

Using Windows 10 Pro build 19041.630 and 3D Builder 18.0.1931.0 (latest)

I didn't notice since I usually don't scale objects with 3D Builder, but today I noticed this weird behaviour when trying to scale an STL, and it doesn't make a lick of sense. One may expect that, when importing any file, the scale % will always start with 100% and, from there, one can upscale or downscale as convenient. However, it's not the case. To make things more weird, it's affected by the measure unit you choose when loading the STL

See this first gif. I'm loading an STL made by myself with other app, in metric units (mm). 3D Builder is also set to mm. Then I repair a minor issue and go to scale, changing the unit to percentage. Instead of showing 100%, it shows 3,94%. But what's worst is that, if I click on the box to change the value, is 3,937%



Now I load the exact same STL but, when importing it, I choose inches. Even though I chose inches, the dimensions in the lower bar still show mm, but not the exact same values as before but a rough approximation for X and Y, and something completely different for Z. Then I click the scale button and... 100%. It makes absolutely no sense, not a single bit. I guess that, if I change the app units to inches in settings, I'd see the lower bar showing inches, but that's not the issue at all. Also, the size in mm when you click on the scale button it's completely different than the previous one, the one loaded with mm units. This renders the scale tool totally unreliable and unusable



Something must be wrong with the app's engine, in the way it's dealing with the units. I don't know if any of you has the same issue and could solve it somehow. It's a pity, because 3D Builder it's an otherwise excellent and easy app for anyone into 3D printing

UPDATE: I realized it only happens when you have to repair the model. If the model is ok from start, scaling works fine no matter the units, but if you had to repair errors, then you have that issue. Since that's mostly why I use 3D Builder, it defeats the purpose