predicting weight of casted 3d print mold?

[lukegonet]

Hello all.

I am on a search for something, and im not quite sure what it is yet.

I work at a fishing lure company, and we make lures from casted silicone molds that spin on a machine and we pour lead into it to mass produce them. To make these molds we want to 3d print a plastic lure, press it into the mold, and make a bunch with the impression of that 3d print out of lead.

The problem is I have been doing this for a month and can't seem to get the weights right. 1oz to 1/2oz is not a 50% difference in size. I need to be able to guess what these items will weigh in lead, but my current method is not working. I use Autodesk Maya, and I use a script called "computePolysetVolume" and I thought it was accurate enough, but sometimes it gives me number waaaay off no matter if the geo is closed or not, or if i delete history or not. Some items just come out with a crazy number. Ive tried uploading them to shapeways to get the volume but they come out with the same wrong number. I downloaded a free trial of Rhinoceros, and it seems to get me more accurate readings. But that is just so temporary due to the trial. How can I really accurately guess the volume?! Or is there another way?

Lead weighs 11.34g per cm cubed. So I round it to 11 and multiply that by the volume of my object in Maya. Has anyone ever done anything like this? Is this the wrong way to approach this mathematically?

Please someone help!!

Thank you

[MysteryAlabaster]

I would try Netfabb, it will give you a volume as well.

Your math is correct at first glance, but you may want to try NOT rounding if you want a really precise number.

The difference you get from rounding vs. not will only get larger the bigger the model is.

[lukegonet]

Thanks for the reply!

I have tried that but when I import my obj or stl it gives me a volume of 0. its not normals or anything like that. Also i round it to 11 because that is what our lead weighs. Any idea why netfabb isnt reading any volume at all?

Thanks

[3dkarma]

Does netfabb say there are any errors in the STL? If it's not closed and watertight it won't be able to compute the volume. The easiest way to get rid of errors is to put the STL through the netfabb cloud service (cloud.netfabb.com).

Looks like Microsoft has taken this over. Hope they keep it going.