Scale and Dimension inaccurate

I have a drawing from my supplier.

I do not know how to change or modify the scale of a drawing.

Scale on drawing says 1:50

But when I check with dimension, all distances are inaccurate.

eg: distance A to B says 500 on original drawing.

When i double check using dimensions, A to B become eg: 956.333322

Appreciate if anyone could help me out. Thanks!

You know what the dimension should be (500). You know what it scales (956.333322). Do the math and using the SCALE command scale the drawing the appropriate amount. Then go back and doublecheck that known dimension. Does it scale correctly now?

Firstly check you linetype scale. type LTS and set it to what you want. I would then check your dimstyle and ensure the scale matches that of what ure drawing is.

a couple of things before you get too far. Are you measuring in paper space or model space?

are you measuring using dimensions?

I would make sure I am in modelspace and use the DIST comand to determine a reference length. If that shows 500 you need to check your dim styles. If it shows 956.333322 follow ReMarks method.

Regarding scale, let AutoCAD do the math. When in the scale command look at the command line and use the Reference feature. When asked for the reference length select the A-B length using snaps then specify the 500.

This way AutoCAD will use its full precision in scaling.

Supplier has probably scaled the drawing by 2 or dimscalelinear by 1/2, instead of using viewports or dimension scales. And classic inaccurate drafting.