3D printing is gaining more and more momentum every day. Desktop 3D printers are very affordable and there are many tutorials on which ones to get, and how to use them. This one is different! Desktop 3D printers are great for printing knickknacks, parts and prototypes, but they still can't compete with the quality of some of the really expensive 3D printers which use different technologies. Online 3D printing services such as Shapeways and i.materialise provide affordable access to these higher quality printers. You can simply upload a 3D model and for a fee, order it in a number of different materials, including nylon plastic, steel, very high detail resin, ceramics, silver and more!

The image above is a picture of a ring that I designed and ordered through Shapeways in their Polished Silver material. You can download the 3D model of the ring for free to follow along with this instructable.

Step 1: Download a 3D Model

First, we need a 3D model that we want to order. For this instructable, I'll be showing you the process using a ring I designed using my Freakin' Sweet Knots software. You can download the model for free here. You first need to sign up for a free myminifactory.com account, then you download the model.

FULL DISCLOSURE: I've entered this 3D model into a design contest, and by downloading the model you're increasing my chances of winning a B9 Creator, a high resolution, resin based 3D printer.

STL files are the industry standard 3D model format for 3D printing. Every online 3D print service accepts them, and is the format the ring is stored as. Download it from the link above and, we'll get started!

Step 2: Shapeways

In my experience, Shapeways is the most affordable online 3D printing service. They are also the pickiest about their 3D printing guidelines. I've had many models rejected, when almost the exact same model has been approved in the past. For the most part, though, Shapeways is my go to 3D printing service. Shapeways is also an online marketplace. You can easily sell your models to others in addition to ordering your own prints. You'll need an account to start uploading models, so head over to shapeways.com and in the upper right corner click 'Join'. You can easily sign up with your Facebook or Google account, or use your email address and pick a username and password. You'll get an email about activating your account. Just click the link and you'll be good to go. The next step is to upload a model!

Step 3: Shapeways: Upload a Model

In the top left there are three links you can click, 'Shop', 'Design' and 'Sell'.

'Shop' is for customers looking to buy a unique product from one of the many online shops people have created on Shapeways. It takes you to a search page, with many criteria that you can specify from price to category and material.
'Design' is for people who want to upload their own designs. It takes you to the list of models that you've uploaded and provides a link for uploading new models.
'Sell' is where you'll go after you've uploaded models and need to manage your shop. You can rearrange the order items appear in, choose which materials you want to sell your product in, add photos, etc.

We're going to start with 'Design' as we need to first upload a model. Then click Upload. A box will popup with a link to select a file. Click that link and select the ring STL file that you downloaded in the first step. Make sure that millimeters are checked for the model units and then click Upload.

Step 4: Shapeways: Order Your Model

Once your model finishes uploading, you'll be taken to the model page for the ring. You should see a preview of the ring on the right-hand side, along with information about the ring on the left including the dimensions of the ring, the volume of material it takes to produce and the amount of space it will take up in a 3D printer. All of these factors affect the price of the model in different materials. Pricing for the different materials should show up almost immediately, but Shapeways performs many automated tests to see if the model is 3D printable. After several minutes (it could take 10-20 minutes in some cases), a green check mark should appear for most of the materials under the Auto Checks column. The green check marks means it's ready to be ordered. If it received a red X instead, it means that the model cannot be produced in that material. The picture of the ring in the intro is Polished Silver, which comes out at $41.48. Not bad at all! You can click the Add To Cart button for any material with a green check mark and check out securely with a credit card or Pay Pal. Once ordered, Shapeways will have manual checks performed by an engineer to make sure your model is printable, and then they'll have it made and shipped to you.

Step 5: I.materialise

i.materialise is another popular 3D printing service. Their pricing structure is different than Shapeways. Sometimes models are cheaper, while other times they're more expensive. Since they're based in Europe, shipping can be pricier to the US. For orders over $129, though, shipping is free, so I'll do that for larger orders. I'm especially impressed with i.materialise's high detail stainless steel. They can achieve very high levels of detail that just can't be done through Shapeways. They also offer 3D printed titanium, which I haven't seen offered anywhere else.

To start with i.materialise, you need to sign up for an account. Go to i.materialise.com, and in the upper right click 'Sign Up'. You'll need to supply your name, email, username and password. You'll be emailed an activation link that you'll have to click before you can sign in and get started. Click that link and then head back to the home page and login with the username and password you supplied.

Step 6: I.materialise: Upload a Model

i.materialise is also an online marketplace where you can browse others' creations and purchase them through their shop. The major difference between Shapeways and i.materialise's shopping experience is i.materialise forces you to have already ordered your model before being able to sell it to others. Having pictures of your product is key to getting sales anyway, though, so it amounts to a very minor difference.

To upload a model to i.materialise click Upload 3D Model in the upper right. You'll be brought to their 3D print lab, where you can select a file to upload. Click the big 'Upload Your 3D Model' button and select the model of the ring.

Step 7: I.materialise: Order Your Model

After the model has been uploaded, pricing will be calculated and displayed next to your model. Clicking a material on the right will show finish options below, which also affect the price. For example, selecting silver as shown in the picture above, will show 5 finish options. Selecting Gloss is roughly like Shapeways' Polished Silver material, which with the Euro being pretty close to the dollar right now comes in at just under $30, which is less than Shapeways. With the added shipping cost to the US, though, it's comparable. You can then click Add To Cart and checkout with a credit card or Pay Pal.

Step 8: Other Services

There are other online 3D printing services as well and they provide similar interface to upload and order a 3D model in various materials. They include:

kraftwurx.com - I've had some very high quality prints made through Kraftwurx, but have also had major delays and complications with their interface.
ponoko.com - Ponoko seems to mostly be a laser cutting/engraving service, but does also offer 3D printing services. I've never used them for 3D printing, though.
cubify.com - I've only ordered a single print from Cubify. It came out great, I've just stuck with Shapeways as they seem more affordable.
sculpteo.com - I've never used them.

If you have any other suggestions for 3D printing services to add to the list, let me know!

Step 9: Thanks!

Thanks for checking out my Instructable! If you liked it, please consider downloading the ring model pictured in the intro to help me in the myminifactory.com B9Creator contest. You'll need to sign up for a free myminifactory account and then you'll be able to download the file. Here's the link: https://myminifactory.com/object/celtic-ring-5346