September 29th is national coffee day! If you're like me then you really can't get anything done in the shop without a cup of coffee in hand. Unfortunately from metal shavings, to wood dust, to oil and lubricants, there are lots of nasties that might end up in your cup if you have in the shop.
That's where a custom lid comes in! This lid fits onto the standard Autodesk coffee mug and allows you to take your mug with you into the shop!
Step 1: What You'll Need
1 cup for refrence
object connex500 (or shapeways)
this design might work on any standard FDM machine printing out of ninjaflex as well
Step 2: Measure the Cup
Using a caliper measure the relavent dimensions. Get the inner/outer diameters, the lip shap, lip depth, and any additional geometry in the lip. Make sure there is enough clearance with the handle. We found the insides of the standard autodesk cup has a strange sloping fillet on the inside, this wasn't in our original measurement and caused problems later on.
Make a crude sketch of what you think the section of the cup is like. Add dimensions as they are recorded. This sketch and the dimensions will be the basis for the next step in Fusion. Don't worry about getting all the dimensions exactly correct the first time-inevitably you will find something you missed while you are modeling in Fusion, simply go back and update your sketch.
Step 3: Modeling the Lid in Fusion: Setup
The first step in Fusion is to begin a new sketch. By Default Fusion will open into the data browser, start a new project if you haven't got one going already then open up the design workspace to get started.
Fusion works on a similar paradigm to inventor-you make a sketch and that sketch is then consumed by an operation to create geometry. Each time you want to add something to the design you will need to create a new sketch for it.
To start the cup we need to model the basic cross-section. Since we will be using the revolve tool to make the geometry it's only necessary to model half of the section. Make a drawing of the basic shape.
When you are happy with your sketch then exit the sketch and select the "create" tab drop-down, go down to 'Revolve'. Select your sketch geometry and the axis to revolve the sketch around. Hit OK to finalize the geometry.
Step 4: Modeling in Fusion: Form Refinement
Once you have the basic shape of your lid in Fusion you can start to shape it to look more like what you're after. The first step we need to do is to cut the top so you can get your lips to the opening without the lid getting in the way. On a standard coffee cup lid this is accomplished by pulling a selection of the 'lip' up.
Since the revolved geometry already has a raised portion we only need to lower the other portion that is not going to be the lid. This is done by using the Boolean Combine tools in Fusion. Start with a 2D sketch of the volume you want to remove from the cup. When you have completed the 2D sketch then use the "Modify" "Press-Pull" command to create the geometry that will cut your base geometry. When you pull it out and it intersects with the existing geometry it will turn red and ghost in the area that is being removed.
Repeat this process to make the holes for the mouth and the air hole.
After you have cut the top of the lid to the final dimensions it's time to start finishing the piece and adding in the fillets. Open up the fillet command under "Modify>Fillet". Select the edge you want filleted and enter the radius dimension.
Step 5: Modeling in Fusion: Final Touches
Once you have filleted the edges and gotten the basic forms down it's time to add the finishing touches. Use the Boolean tools to remove any material that is still existing. This design is intended for injection molding so it is important to keep the wall thickness as consistent as possible, it is also necessary to add Draft angles but I will cover that in another instructable.
To add a logo to the lid, create a "Base Feature". Here you can import or model a logo. Intersect that model with the lid and use the "combine" function to make the geometries solid. You're now ready to make your first 3D print!
Step 6: 3dprint, Test, Iterate
Now the real fun begins. At Pier 9 we have access to the amazing Objet Connex 500. It uses a photo-polymer to solidify an object layer by layer. Start by printing out your first design. Go though the standard printing and post processing cleaning. Once your lid is clean and dry give it a shot on a test mug. Chances are the fist one won't fit.
Now we need to figure out how to make it fit, you can make some modifications then reprint the lid but a better approach is to locate the pinch points that are not working and focus on modeling those. To figure out exactly how to optimize the fit of the lid I ran over the the shop and used the bandsaw to cut the lid in half. This allowed me to see exactly where the problems were and focus on that. When you're ready print another version.
Step 7: Final Design!
After 3 iterations I got it right! The inner lid maintains the watertight seal while the outer lid keeps the entire lid on the cup. Testing the lid on multiple cups there was a slight variation in the fit, but due to the material it was able to work on all of them.
So there you have it, a 3D printed lid for an Autodesk cup. I've attached the file so you can make your own. Now unless you have access to FDA approved material I wouldn't actually drink out of this, there still is support material on the surface which would not be good to drink. In order to really productize the piece and make it safe we have to take the next steps:
3D printing is great for rapid iteration and concept development-but what if we wanted to make 500 of these lids? That's where injection molding comes in, at Techshop in San Francisco they have a small injection molder perfect for this. I will be going over the process of going from 3D Printed prototype to final injection molded project in an instructable coming soon.
thanks RobbGodshaw for the sweet autoplay embed code!