# Are my cost calculations correct?

Discussion in 'General Discussion' started by outspoken, Oct 25, 2012.

1. outspoken New Member
I have what is essentially a solid rectangular model with the following dimensions:

Code:
```104mm width
60mm height
215mm length

mm3 = 1341600
cm3 = 1342
```
Now the cost of material for strong plastic is \$1.40/cm3 so does that make my model cost \$1800?

Code:
```SFP(\$1.40/cm3) * 1342 = \$1878.80
```
I hope my math is way off, otherwise I'd just as soon go buy my own printer.

2. Youknowwho4eva Shapeways Employee Community Team
You're only off by the \$1.50 startup cost. You should make your model hollow to save some \$.

3. outspoken New Member
Shipping and handling too right?

It does have hollowed out areas, probably 75% of it is hollow. Basically imagine a pill container.

I just wanted to make sure my understanding of the cost scale was correct. Later today I'll upload it for examination to determine exact costs.

Thanks.

4. Youknowwho4eva Shapeways Employee Community Team
It's all volume based, not bounding box based. So if you item is hollow it will be significantly less expensive.

5. stonysmith Well-Known Member Moderator
6. Fredd New Member
Outspoken; I believe the reason the hollowed out area is not having any effect is the interior surface face normals are not pointing inward. If this is corrected, your volume measurements should change dramatically. You still will need to create a tunnel between the outer and inner surface to create drainage, and to create 1 uniform surface. Best example is to create a large cube, normals facing out, create a duplicate,scale it, flip the duplicates face normals, then center it inside the larger cube. Join both meshes, then use a boolean difference modifier to create a tunnel connecting them.

The reason I think its normal problems is that I used your dimensions, got the same volume.

7. Youknowwho4eva Shapeways Employee Community Team
So far he hasn't uploaded yet, so he's not getting his volume/price from SW yet. Those are good things to keep in mind if you volume doesn't match what it should be after upload though.

8. outspoken New Member
This must be the problem. I am very new to 3D modeling so I'll make sure to attempt this over the weekend.

I was able to get a competitor to analyse and provide a quote and everyone is correct about the price, it was much much lower.

Though my model is far from printable apparently.

btw, I have a horrid time trying to remember shapeway's site name, all I can think about is the grocery store Safeway.

9. Fredd New Member
You know that you can upload a model to Shapeways, not safeways and it will not cost anything unless you order it, to check dimensions,if printable, cost per the different materials free. I was proud of that when I uploaded a test that's price would have been \$5000.lol
You need help with the file, just post it here. I think safeways would charge you for a sack.
Keith