Introduction: Make 3D Printed Bicycle Rings (with Rhino for Mac)
While there's plenty of useful things you can make with 3D printing I'm going to show you how to make something a little more fun-- jewelry. I'll be going through the steps I went through to create my Bicycle Rings, but since this is an original design that I've just started selling in my Shapeways shop I recommend coming up with your own design if you plan to 3d print it. Rings don't have to be conventional so you can put anything you like on top of a band -- a pineapple, your favorite pet, a bust of yourself. Whatever. Have fun with it!
What you'll need:
A 3d modeling program. (I'm using Rhino for Mac in this instructable)
An original concept. (though you can try modelling the parts for the bicycle rings shown here before moving on to your own design)
A 3D printing service. (I use Shapeways)
Step 1: Sketch It Out
I recently came up with the idea for the 3D Printed Bicycle Rings when I was supposed to be working on something completely different (as is often the case for me). I have a mini obsession with bicycles new and old (and my little Pinterest board reflects that) so I'm guessing that had something to do with this idea popping into my head. Whenever I have an idea for a new design the first thing I do is some quick sketches to work through the concept. I know there are people that are comfortable enough to go straight to 3D modeling from that initial spark, but I've never been one of them. And for me personally I don't think any technology will ever replace a quick and dirty conceptual sketch. I recommend working with sketches for beginners as well. Sometimes an idea seems great in your head but if you try to model it you can quickly get stuck and frustrated. It's much easier to work it out in sketch form.
Aside from developing the general concept you can use the sketches to figure out how to model the various parts. It's hard to decipher from my messy, small sketches but I have one area where I figured out how to attach the bike frame to the wheel/ring band. I really needed to do that before I tried modeling it.
Step 2: 3D Modeling Your Design - Some Basics
There are a lot of different options for 3d modeling programs and many of them appeal to specific groups - animators, jewelry designers, architects, etc. Because my background is in Architecture and the first 3D modeling I did was architectural, I tend to gravitate to the ones that are geared towards architecture or commonly used by architects and students. The one I use now and can recommend only if you will be doing a lot of 3D modeling is Rhino for Mac. [This is also what all my screenshots for this project are from.] This is pricey though so for most beginners a program like Sketchup or a short term trial of any Autocad 3d program will probably do. You just want to make sure that it can be exported in a format that works for 3D printing.
Regardless of how you are going to embellish your ring(s), the first thing you want to get out of the way is modeling your ring band. Though the tool I used to achieve this is specific to Rhino for Mac, you'll find that when you've tried enough of these 3D modeling programs there are certain tools/modeling transformations that are consistently used in nearly all the programs like sweep, revolve, and boolean operations. I didn't quite get this when I was starting out, but it's much better to have a solid conceptual grasp of what those tools do than exactly how to make it happen in each program. And understanding those tools gives you a much better idea of how to model whatever you're going to make so you don't get stuck.
Tip: Before modeling you'll want to know what thickness to make your jewelry. For most materials it's best to make all your parts at least 1mm thick. With some materials you can go thinner but that will affect the structural strength of your parts.
Step 3: Making the Ring Band (The Bicycle Tires)
So creating a ring band is actually fairly easy, especially if you want a simple one with a consistent shape throughout. Initially I made a circle with a Sweep1 command along the rail. What this does is take that small circle profile in the screenshot and "sweep" it along the larger circle to create the the 3 dimensional band. This would be fine except that I wanted my ring band to look a little more like a bicycle tire so I needed more detail. I went back to the small circle and created some indentations, then again used the Sweep1 command to get a surface that looked something like a rubber tire on a metal rim.
After this I added fenders. I started with a flat shape that would become my fender. I then used the Flow Along Curve tool to take this shape and bend it along a curve. I made a copy then modified each fender for the front and back tire. Now I had enough detail for the 2 tires/rings.
Tip: It's a good idea when designing something for 3D printing to think about what material the final model will be printed in and add the appropriate level of detail. In this case I wanted it to be printed in Stainless Steel which means not as much detail will come out compared to precious metals so there's no need to go overboard on the detail.
Step 4: Making the Bicycle Frame and Handlebars
To make the bicycle frame and handlebars I used the Sweep1 command again. In both cases I created a profile and rail and swept the profile along the rail. I added some additional details like grips for the handlebars but again because I'm printing this in Stainless Steel I didn't do an excessive amount of detailing.
Step 5: Adding the Seat, Storage Rack and Basket
Of these last 3 parts the storage rack was the easiest to model. I had a 2 dimensional shape that I extruded and then used the Flow Along Curve tool to give it that subtle curve at one end.
The bicycle seat definitely took more time. I created a series of curves for the overall shape I had in mind plus a flat outline these curves are contained by. I selected all the curves then used the Surface from Network of Curves tool to create the shape. It's okay when doing something similar if the curves aren't right the first time. You can go back a step and click on the individual points and modify them until you get the form you're looking for, and then use the Curves Network tool to see how it looks.
With the basket I created a flat checkerboard pattern of cubes with 2 different heights that would become the textured surface of the basket. For the form of the basket itself I used two curve profiles for the top and bottom of the basket, used the Loft tool to create a connecting surface (see photo), then wrapped my checkerboard pattern of cubes around this surface using Flow Along Surface.
Step 6: Exporting Your Model and 3D Printing It
While Rhino has the ability to create a mesh of the model that is ready for 3D printing, I tend to not use this option. There are a couple of reasons for this. One is because I'm a little bit of a messy modeler and don't trim all my pieces neatly (I tend to not use boolean operations), and that doesn't create the nicest mesh. The second (and more important reason) is because I've found that not cleanly joining all my individually modeled parts works out much better when there is an issue later on that requires me to modify just one part of my model. I've often had models that I've 3D printed dozens of times get rejected because a technician at the 3d printing service now thinks it's too thin in one particular spot. This allows me to go back and fix that part without affecting the whole model. This isn't necessarily the best method but the one that seems to be working best for me.
My alternative to using Rhino's built in features is a program I've been using long before I started using Rhino called Netfabb. After I've exported my model as an .stl file I bring it into Rhino and run repairs on it there. If there are any major issues preventing the model from being printed, Netfabb will show this (and I can go back into Rhino and try and fix this). If the issues are minor, Netfabb will repair them and prepare the file for printing. I use a basic version of Netfabb for Mac which sadly appears to be no longer available, but there is a trial for the Windows version. There are other alternatives out there and you could always use the built in options of your 3d modeling software (which eventually I may have to do myself).
When I have a clean model for printing I upload it to a service like Shapeways and cross my fingers that all is good. Just remember that even when you think you have a clean model and meet all the minimum thickness requirements for whatever material you are printing in, there still may be issues-- so be ready to make some changes to your model if necessary. But when everything is good, one day you'll open up a package you got in the mail and find some really cool jewelry in there that you made yourself... with the help of 3D printing.