Cheaper By the Dozen: My First Shapeways Experience

     Well, as usual, dabbling in a discipline opened a lot of doors to other interesting subsets. A friend of mine started asking about rapid prototyping and the costs involved in having items produced for use as masters in spin casting. The first place that came to mind was Shapeways. So I started looking into their products.

     Shapeways' online documentation is easy to understand and their tutorials were clearly written. I was especially interested in their tutorials about making models ready to print using  Blender. I spent about an hour reading through these files and looking at a number of products that others have already made available. Then set out to model a simple scenic gaming element.

     I have one garbage can that is sold as part of my Gideon's Dust Redneck set that people have asked to have put in a multi-pack. So I decided to use that as my subject in Blender. I spent about an hour modeling the basic can. A lot of that time was learning a few more commands to make it the shape I wanted. Here is the end result. Very simple, but it has the basic trash can features.

     The next step was to check the normals. Normals determine which way the light reflects from the object. If they are all on the outside, it appears correct. If some are reversed (on the opposite side of the faces), you have a light absorbing or passing through effect. Sometimes the faces show as black, other times they are transparent and you can see into the center of the object. Either way, if the normals aren't corrected, the model won't print correctly on the 3D printer.

     After the normals I needed to check for watertightness and non-manifold faces. Watertightness is basically making sure that all seams are closed and there aren't duplicate vertices that could cause problems. Manifold faces occur when you have more than two planes joined at the same two corners. This also causes problems with printing. Luckily there are easy, one-button fixes to most of these issues in Blender. So it took about a tenth the time to actually do the checks as it did to write about them here.

     With all checks done, the next hurdle was to upload the model to Shapeways. That requires an account. I took some time to set up Highlander Studios 3D. Uploading requires particular scaling, so it was back to the Blender drawing board to rescale my model and save the object. Shapeways accepts several file formats, but I used the recommended .stl. Uploading was simple after that. Choose the file on your computer, choose the scale units (mm in this case), and upload. Shapeways checks the model for printability and sends an email if it has problems or when it has been added to the site. Pretty darned slick.

     Single Trash Can Model

     Shapeways charges a flat handling fee plus a price based on the volume of material consumed. The owner also adds the markup he'd like for profit. One model before markup would cost almost $2.00 for their cheapest material. That's fine for having some prototypes printed in assorted materials for vulcanization tests, but expensive for customers to buy. On to the next step.

     I saw several examples of products that had multiple items sprued together. I decided a dozen would be a good number to sell in a set and it was back to Blender. This was the longest part of the process. Blender has some great functions for duplicating items and connecting items into a single unified piece, but the sequence to make it work correctly without a lot of fiddling later was tricky. There's a Boolean function that will add, subtract or choose the intersection of two parts. That's slick, but the part added is duplicated and needs to be deleted or it craps up the model. I fought the good fight and won out in the end. Here is the result.

     Again, I needed to check the normals, watertightness and non-manifold faces. No issues were found. The model was then scaled correctly and uploaded. Five minutes later, the email from Shapeways arrived letting me know that there were no problems found and the model had been added to the shop.

15mm Trash Cans (12)

     I checked the prices, chose the materials I wanted to make available and decided on the markup for profit I wanted. Twelve cans at $10.34 for a dozen is much cheaper than the single can price. It's still a little pricey for what it is, but they're available in some form until I actually have them made in metal.

     Overall, my first experience with Shapeways was a really cool learning exercise. I gained a lot of confidence using Blender and the Shapeways interface is quite painless. I look forward to using more 3D printing to make prototype parts both for sale at the Shapeways shop and for more traditional metal casting methods.