Multifunctional Arm - Over-engineered phone holder

I wanted to create a smooth action phone holder that uses a sliding mechanism. So, I created this one.

Required Hardware

• 7 M3 threaded inserts

• 7 M3 bolts

• A few rubber bands

• Some foam pads (see title picture)

Printing settings and materials

• 0.4mm nozzle with 0.2mm layer height

• All PLA except the gears and shafts which I printed in PETG

• 3 walls or more for stability

Assembly

Insert the threaded inserts and check that they sit flush with the surface. Then insert the rubber bands like on the photo.

Glue the parts of the racks together using super glue. Take care that everything is square.

Insert the rack into the bottom part of the cassette and then the gears with the shafts installed already. Make sure that everything is symmetric. Use the markings on the parts or count teeth on each side.

Now, close the cassette with the top part and install the first 2 screws (the shortest ones).

Now install the mount with the remaining screws. The shorter one goes into the center hole. Ignore the clamps and rubber bands already installed on this photo. I forgot to take a picture at this step :D

Now, we can flip it over and fiddle the rubber bands into the slits. I tried different sizes of rubber bands but it came out best using two shorter bands on each side that I double looped. So, in the end there are 4 bands on each side. Not all have to be used. Adjust according to the needed clamping power.

Lastly install the clamps using super glue. It can be a tight fit. If it's too tight sand down. Use some foam pads or rubber bumpers for more friction between phone and holder.