Video overview:
https://youtu.be/AARuF0EXpEc

Do you have a Mini Cooper and want a really cool place to hang your keys? Do you also have a 3D printer and like getting paint everywhere?

Well, if you answered yes to these questions, the you are part of a very small demographic and this project is for you!!!

In this project you will create a very groovy Mini Cooper key holder. This includes a quick look into the design process and a thorough explanation of the finishing process.

Step 1: Materials

A 3D printer and computer
PLA filament (or whatever you want)
Black paint and primer spray paint
Silver metallic spray paint
Clear Spray Glaze (from the spray paint section)
Painter's tape
Scissors
Tweezers
Patience and good will towards man
3M wall strips

I'm using a MonoPrice Mini Select printer and krylon brand paints.

Step 2: Design

I have good news. You can just skip this part and download the file here and start printing:

http://www.thingiverse.com/thing:2010668

However, if you want to know how this was designed, here is a very quick overview.

1. This was designed in tinkercad, available at tinkercad.com

2. You can make the mini-Cooper logo itself from scratch by creating a vector file in a program like Inkscape. However, the number one rule of 3D print is build off other people's work (like plagiarism but with permission). I built the key holder into the logo design available on thinkiverse from user Losicek: http://www.thingiverse.com/thing:1614494

Import this logo into tinkercad

3. From here, insert two cylinders that are about the size of the middle of the logo (3a). Make one cylinder a hole and stagger it over the other cylinder so that only the bottom edge of the cylinder is showing (3b). Group these two items (3c).

4. Next add a cube the size of the key lower part of the key (4a). Make it a hole and put it over the bottom of the shape created in step 3 (4b). Group it to the crescent shape (4c).

5. Insert another cylinder (5a). Make it thin and line up over the circle logo(5b). Add a new cube, make it thin, and use it as a hole to cut in half the new circle (5c).

6. Add one last cube, thin it, and line it up down the middle (6a). Make it a hole and group it (6b).

7. Measure your key and adjust the overall model to fit.

8. You just download the file didn't you?

Step 3: Print the Model

I used a layer height of .0875 and a 20 percent fill. I also used green hatchbox PLA filament and a Monoprice Select Mini printer.

This print took less than two hours. I used brim supports where it touched the build plate.

I think this model will print with most settings, it's pretty basic.

Step 4: Clean Up/prime

This model came out really clean for me, but you can clean away imperfections with an exact knife and sand it if you wish.

At this point find a well ventilated area and protect from overspray by laying down paper or a drop cloth.

Use your black paint and primer to put a thin coat of black over the model. Don't worry about covering it all at once, several light coats is way better than a heavy one. Apply additions coats with a 1 minute wait time between each until the model is covered.

Wait at least an hour before continuing. Take a break and watch some Netflix.

Step 5: Tape Off the Model

Now for the tedious part. Using the scissors, tape, and tweezers you are going to cover everything that is supposed to be black with tape. This is annoyingly slow, but you can do it. Once everything is taped, you're ready for the spray paint. (Look at the final product pictures to see the color scheme to know where to tape.)

Step 6: Silver Spray Paint

Use the same method you used with the primer and be really careful not to over paint. This paint will take longer to dry and the can suggest waiting 24 hours to touch.

When you are confident about the dryness of your model, remove the tape. If there are some place that get messed up, spray some paint in a plastic cup and apply touch ups with a brush.