3D Printed Phone Mount for Cycling

Hello everyone, this is my first Instructable, and my first time 3D printing an actual project as well, so I hope you enjoy, and feel free to critique/ask questions. Please vote for me in the First Time Author Contest and the Outside Contest if you like the project!

The premise:

Over the summer, my school loaned me a 3D printer to use and get familiar with, so I ended up back at home with a BEETHEFIRST 3D printer sitting on my desk (pictured).

Recently, I acquired a new road bike, a lovely Trek Alpha 2.3 in lime green which I began taking out for rides more often than my previous bike. In the past, when I needed to take my phone with me on longer rides, I would have to duct tape the phone case to my bike stem and then put the phone back in. Needless to say this was not an ideal solution!

So on the first week of the summer, I put the two thoughts together and came up with an idea: I would 3D print a mount for my phone for when I go cycling. This would let me customise it completely, allowing for a better fit and aesthetics than something I could buy at a shop. Besides, I had loads of time, so I figured, why not?

So let's get started!

I started out with a rough sketch of the mount and came up with a design that incorporates three separate pieces and is held together with bolts. After rooting around in my box of miscellaneous parts, I dug out a couple of M5 bolts and an M4 bolt, along with an M5 nut, which should work well for the project.

The phone I'm designing this for is an iPhone 5s, and I found the dimensions on the Apple website, giving me the measurements as:

• Thickness: 7.6mm
• Width: 58.6mm
• Length: 123.8mm

To account for tolerances in my 3D printer, I added a tenth of a millimetre to all dimensions, ensuring the phone will fit in the case. The three different parts are labelled in the image, and once I measured the diameter of the handlebar (33mm) then I was ready to move onto CAD modelling.

Part 1 is the phone case element of the mount, and the most crucial in terms of accurate dimensions, as I don't want my phone to fall out on a bumpy ride. I will be printing all test models in blue PLA filament, as I have an excess of it, and the final pieces will be printed in neon green, to match the bike's colour.

I modelled the all parts on Autodesk Fusion360, allowing me to export each file in an STL format, used by the 3D printer. The first case was printed, and from it I learnt several lessons. The sidewalls holding the phone in were both too long and too thin, and thus cracked when the phone was inserted. The clip at the top was also too thin and cracked. The hole I'd printed centrally for the bolt was too small, and the base as a whole was slightly too thick. The next iteration would save on filament and print time by thinning this.

From there, I redesigned Part 1, shortening and thickening the sidewalls, and reinforcing the clip as well. The base was thinner, and the mounting hole larger. However, the clip at the top still broke, and the base still wasn't quite as flexible as I'd liked, so I altered the model one last time and switch to neon green filament, in order to print the final part.

With the neon green filament installed, I started to print the final piece, using the BEESOFT software to export the STL (attached) to the printer, with 25% density and Medium resolution. Halfway through the print, I had to change the nozzle, which had become blocked, but after restarting the print, the part was ready after three hours and finished perfectly.

After I had removed the support material, the phone fit perfectly in the case. The hexagons in the case increased the flexibility, and decreased the amount of filament and print time as well, although I'll admit they were mainly an aesthetic feature at first. I've attached the STL file for those who have an iPhone 5 or SE. But after this piece was finish, I was free to move onto Parts 2 and 3, and so switched back to blue filament.

With the diameter of the handlebar, I designed the other two parts on Fusion, and printed Part 2 in blue. From this I found the part was taller than it needed to be, and the holes were too small for the M5 bolts. After changing this, I almost halved the print time for the second prototype and I was ready for the final part. For Part 3, I printed a smaller test piece to confirm the bolt hole diameters, and, once confirmed, I was ready to print the final part as well. As I had modified Part 2 of the CAD of Part 3, I was confident that all measurements were accurate. From here, I switched over the filament and began printing.

The final parts took about an hour each to print out, and worked out very well. I test fitted the bolts, and the printed threads in each hole were secure enough to satisfy me so I then fitted the two parts onto the bike. The fit was a little loose, so I added a coating of clear silicone to the inside of each part, to ensure it wouldn't slip on rougher road surfaces. After the 24 hour curing time, I assembled the final parts on my bike and test fitted my phone.

I fitted the mount to my bike and fitted the phone inside. The fit was snug, so I took it for a short test ride to see how it fared. After the ride, the mount held the phone securely over a variety of road surfaces, from smooth to fairly rough, as well as some minor potholes.

Overall, I'm happy with how the mount turned out; I think it looks good on the bike, and it holds my phone securely when I'm riding. If I have to replace it in the future, I think I will see if I can streamline the design further, cutting out more filament if possible so it will be faster to print. And of course, because the bolts take a while to screw together, I'd look into other faster and equally secure methods of fastening. But it sure beats duct taping my phone case to the stem, so I'm happy! Thank you for reading, please vote for me in the First Time Author Contest and the Outdoor Contest if you enjoyed this!