In this instructable I will teach you what I learned when designing my own 3D printed fidget spinner so you can avoid makeing the same mistakes. Now personally, I don't care how cool your 3D printed creation is (and trust me some of them are REALY cool) if I didn't design it myself. Because honestly, all you prove when you recreate someone else's creation is you're good at following instructions. But when you design something yourself, that takes skill, time, and perseverance and that's what makes me proud. So today you won't be copying my fidget spinner. Instead you will be doing something really cool, designing your own. Here's some tips and tricks I've learned along the way.
Step 1: Tip 1: Don't Be Afraid to Mess Up
Lesson one, don't worry about messing up. Above is a picture of all my prototypes and as you can see I didn't get it first try. You actually do learn allot through trial and error, more than you would just getting it first try, so don't get discouraged.
Step 2: Tip 2: Have Margin
One of the biggest lessons to learn in life is things aren't perfect and this definitely applies to 3D printing. No 3D printer is perfectly precise so you've got to account for some printing error. I've found about .15 mm's does the trick. You want to have this margin between pieces that fit together either printed or otherwise. So if I wanted a cube to fit in a 4 by 4 mm hole I would make my cubes width and length both 3.85 mm not 4 mm. Now you may be thinking, "That's not even a forth of a mm! could that really make a difference?" Originally, I didn't think so either and guess what, my bearing didn't fit inside my print! so yes, yes it does make a difference.
Step 3: Tip 3: Can It Come Together
The next thing you need to ask yourself is can your design be assembled. Now, because you have a non-3D printed part (AKA the bearing) its a pretty good idea to make multiple pieces. Doing this allows you to take your spinner apart so you can clean your bearing and allows you to replace a piece instead of the whole spinner if something breaks.
Step 4: Tip 4: Double Check Your Design
Make sure your design is sturdy. As you can see my original design was connected together by only a mm thick section of plastic. I soon found that such a thin bit of plastic couldn't endure the wrath of my pocket so make sure that your design will hold up under the wear and tear. The best way to do this is to print a rough prototype and test it out.
Step 5: Tip 5: Make It Heavy
Fidget spinners need to have weight behind them in order to work and unfortunately 3D prints are pretty light. Now a great way to add weight to a print is to make sure your printer is set to 100% infill. This may take longer and cost a bit more but its totally worth it. Setting your printer to 100% infill means your creation is 100% plastic and the printer doesn't make gaps inside your print. This adds stability and weight, and for a fidget spinner thats a win win.
Step 6: Tip 6: Round Out Your Edges
Rounding out all your edges is a good idea for three reasons. One its nicer on your fingers, two it looks smoother and three the printer likes it. You dont have to round very much, even half a mm will do, but its defiditely a good practice to have when designing your spinner.
Step 7: Tip 7: Dont Over Size
Honestly if you want to be able to really fidget with your spinner you don't want its diameter more then 9 cm or else its likely to hit your hand as you spin it. However this does entirely depend on the size of your hand so just make sure your spinners diameter is appropriate for your hand.
Step 8: Tip 8: Give It a Bear Hug
Lesson number seven is make your print bear hug your bearing. If the spinner doesn't squeeze your bearing it will slide around adding extra friction and thus making your spinner less efficient. So you really want your measurements to be as precise as possible and the only way to do that is through some trial and error.
Step 9: Tip 9: Have Fun!
You would think this would be a given but seriously it can get pretty frustrating having your design fail. So make sure you have a good time because otherwise there is no point. Comment below if this helped you and send me a pic of your spinner when you finish.