# Jewelry metals weights difference

I’m user of matrix 9.0 with rhino 5 and I have this issue. The weight of the metals in the simulation in matrix 9.0 with rhino 5 does not correspond to the weight of the final model after 3d printing, metal casting, cleaning and a quick finish. The difference is quite large at about 14.3 percent less for example for silver. Can you help me clarify if the other jewellers who work with matrix 9.0 have the same problem and if there is a constant for each metal that we have to subtract from the weight given by the simulation in the program?

Hi - you might want to contact Gemvision for support with this issue.
-wim

I wrote them the same question

Assuming Rhino gives you the correct volume, the weight that any software gives you is correct if it uses the correct density (which for jewellery is historically established). All those processes alter the actual volume or surface and there is no easy way to measure the error, because for some of those processes it is related to area and some to volume and some to edges… and they can’t generalise it either because your manufacturing processes are not those of another user…So I think that yes, it is a problem that everyone has, but in some pieces it manifests a lot and in others a little.

I think the best solution is to separate your production into one, two or three levels of complexity (where a sphere is 0 complexity and an extremely sharp shape is very complex), and measure the error of each piece, at least 20 or 30 samples per group. Then for next pieces you just categorise it into the proper complexity-shape group and use that estimated error (an average) for that group. The more samples you use and the more complexity groups you have, the more accurate you can be.

You will never get a correct value. You loosing volume while casting (the investment for casting will shrink some percent) and quick finish. The mixture of the alloy is a factor too. As example a yellow gold only containing Au/Ag/Cu has a other density as a yellow gold containing some other helping materials for casting.

So matrix will not be able to fit any process perfectly.

As Dani_Abalde say you need to make some samples and get your own factor.

Great Thanks!!!

Great Thanks!!! I wanted more to see if all others jewellers have same problem, I will do your advice I bag apologise for my poor english.