Manufacturing guy-at-large.

Modeling for SLA

Added on by Spencer Wright.

I spent a little while today optimizing my dummy headset for 3D printing. In subtractive manufacturing, cost can often be estimated by calculating the difference between the mass of the raw material and the mass of the finished object. The more material you need to remove, the more fabrication time and resources you'll consume producing the part, and hence the more expensive (generally) it will be.  

The cost structure of 3D printing is totally different. With additive techniques, cost is a largely a function of the mass of the finished object (envelope size also has an effect in production settings, but it's less critical). The cost of a part comes down to how long it takes to make, and production time is limited by the amount of material the machine can spit out in a period of time. 

As I noted the other day, my dummy headset is a bit more expensive than I'd like it to be. On the upside, though, I can remove material in a bunch of places! I took the revolved part in Inventor and made a series of revolved cuts on the ID of the part. I left some ribs along the ID to keep the perimeter somewhat intact, and left the areas right around the set screw holes thick. 

Shown before I mirrored the cuts onto the top side of the part. 

I was able to shave a *lot* of mass off the parts - more than 45% on the lower part - which means significant cost savings. 

Shapeways' volume/price breakdown.

I still need to make sure I'm on the right track on clearances in a few locations,  but cutting the extra material out should make these parts much more feasible. Keep in mind, my total development cost at this point is probably 2.5 hours of labor and $40 in parts. Were I trying to get this product to market quickly (and who knows, I may try doing so) I could be live in both Shapeways' - and my own - webstore within two weeks.

Even though I've just been playing with it for a half hour, it's pretty cool seeing my model live on the site.