I recently picked up a used BMW E46 and noticed the door panel trims were all hanging on by some duct tape. When I went to inspect, I noticed that all the clips had been broken and replaced with silicone rubber to try and hold it to the door. With some CAD and 3d Printing, I set out to replace them all and restore my door panels to their former glory.
To start off I found one of the broken clips that was still relatively together. Then I took out some callipers and measured all the important dimensions. Notably the dimension of the round metal clip (it attached to a plastic clip on the panel) and the outer dimension of the rubber part (it pushes through the actual door, and the clips lock it in place).
Once I had some quick sketches of those dimensions, I went and measured the dimensions of the panel clip and the hole in the door. The dimensions matched, so I knew that I wasn't going to waste any time printing clips that would be too large. Great, now over to Fusion 360!
To get my model I just followed basic sketch & extrude workflows, making sure the 2 important dimensions were correct. For the overhanging clips I used the Chamfer tool to add a gradual increase out of the side of the model, I really wanted to be able to print this part without supports and it would require the right angle on those parts. I added a .5 mm fillet to all of the edges in the model to give it a smoother finish.
After exporting my model as an STL, I loaded it up into Cura. The filament I had decided upon was ABS as PLA would likely melt/break in the higher temperatures my car experiences (especially since it is summer at the moment!). Slicing this model for an ABS print required me to add in Brims around the base of the model. I sliced these parts at 0.25 Layer Height and decided on a 100% infill % too. That should give me a strong, durable plastic clip for my door trim.
Duplicating the model on the bed, I eventually got 16 individual clips loaded up onto my Taz 5s bed in Cura.
2 Hours Later and I had some really solid plastic clips! They fit into the trim perfectly, and now All of the panels in my car are fitted back into place, no duct tape or Silicon required! This was a pretty simple project, but the difference is night and day!