I tried (and failed somewhere) to build a P40 italian tank

[Raminator]

" measure the imported mesh"

I think I may have been already doing that?

Doing some very rough scaling from these blueprints and knowing the size of the tank (5.8 metres long according to Wikipedia), the bit you've measured above should be 120 mm long, not 1200. It just looks like you've accidentally missed a decimal place when you were scaling, so you just need to scale everything down to 10% and you'll be good to go.

[RichieFL]

" measure the imported mesh"

the bit you've measured above should be 120 mm long, not 1200. It just looks like you've accidentally missed a decimal place when you were scaling, so you just need to scale everything down to 10% and you'll be good to go.

I think that you read the blue print and the image wrong? (they both show 120cm) or am I missing something?

[Raminator]

Sorry, I should have been clearer; I meant the blueprint I linked, not the one you had drawn.

P-26-40.png (664.32 KiB) Viewed 320 times

We know the distance between the red lines is 5.82 metres (or 5820 millimetres for the sake of clarity), and we can measure the distance between the green lines using your CAD software, drawing software or even a ruler against the screen. The distance between the green lines is ~31.3% of the distance between the green lines, so on the real vehicle that panel is 5820 x 0.313 = ~1824 mm long. A 1:16 model should then be 1824 ÷ 16 = 114 mm, or about 10x less than the 120 centimetres (i.e. 1200 mm) that you had on your blueprint. 1200 mm is nearly four feet; you're not going to fit that on your 3D printer!