I used to own a Garmin Outdoor GPS which was perfect for hiking, and using on the motorcycle. It was the Garmin GPSMap 60 CS. It was rain proof, lasted long on it's 2xAA batteries, and was very useful for navigating.
Sadly it got stolen when my backpack got lifted...
I needed to get another replacement, but could not afford the high cost of another outdoor GPS. I opted to buy a second hand Garmin Nuvi 30, which costed about one tenth of the Garmin GPSMap. It operated effectively, but the standard ball-joint & suction cup would not work on the bike. I know of the available clips online, but could not find any at a resonable price locally. I decided to see how I could adapt the standard Nuvi Cradle, and link it to my remaining GPS mount clip, which is what I used to use for the previous GPS.
Step 1: Critical Dimensions Leading to CAD
I decided to 3D Print a bracket which fits around the Nuvi Cradle section, and is able to clip into the existing GPS Bar-Mount. For this to be printed effectively, the CAD model would need to be accurate and toleranced effectively.
Using a pair of vernier calipers I carefully measured all of the mating faces and modeled a suitable bracket.
Step 2: CAD Development
I modeled the components using SolidWorks 2014. Once they assembled effectively I prepared the bracket component for 3D Printing through this production flow: Solid Works Part Environment > Save part as high resolution STL file. Open up STL file in UP Mini Software and prepared the file for Solid Printing at the machines Highest Resolution (0.2mm layers). Printed on Up! Mini using natural ABS plastic.
Step 3: Assessment of the 3D Print
I assembled the components and they fitted together well. Some areas were too tight, and I assume the printing layers (and my overenthusiastic tight tolerancing) lead to the parts being a bit too snug. I marked up the areas where the CAD model needed a bit of tweeking.
I wanted to thicken the entire bracket by another 1mm wall thickness, which lead to me using this iteration as a developmental model.
Step 4: Finalising and Finishing the Final Bracket.
Once I was happy with the CAD component, I printed it in the same manner as the first (ABS, Solid, 0.2mm Layers).
To fuse the entire component and make it stronger, I paint over the surface with a charged paintbrush full of Chloroform, or MEK. This melts the plastic and creates a homogeneous surface. This surface is stronger, sands easier, and can take paint more effectively.
I opted for mechanical fasteners to hold all the printed bracket to the Nuvi Cradle. This is due to the fact that the components are different plastic types and I wouldn't trust an adhesive to attempt to hold these two together over rough roads and bumps.
3mm Self-tapping screws did the trick.
Finishing: The plastic was natural ABS Plastic with extremely nice workability and suitable strength, but practically zero UV protection. This would result in the bracket immediately deteriorating and becoming fragile as it is exposed to sunlight. I decided to spray the bracket with a thick coat of enamel spray. I disassembled the bracket and sprayed the entire outside of the component. Once dry, I was glad I took off the 0.5 mm in the mating surfaces, as the paint was surprisingly thick.
Step 5: Finished Bracket
I assembled the final bracket and it worked out perfectly.
Several questions which I foresee possible be coming my way:
What about the power?
I have a 12V lighter socket under the seat, and can run a usb power cable under the seat and up to the GPS. I mainly do short trips around town so its easier to just pop the GPS in and go. If there are any suggestions on how to leave the USB Cable in place and some-how waterproof it please let me know.
What about the rain getting on the GPS?
The thunderstorms here are fast and generally end quickly, I try wait them out. So until I buy a waterproof GPS, I will just have to put up with this one for meanwhile.
I will try and upload some CAD Screenshots tomorrow, however I hope this is interesting in the meanwhile.
Any comments or questions please shoot!