Convert a Cellphone Mount to Support a GoPro

I was looking for a vacuum mount to hold my GoPro camera inside the car windscreen.
After searching for the best deal in various places and having difficulty deciding which one to get, I remembered that I've already got what I need, I just needed to carry out a simple modification and Voila! "just what the doctor ordered".

I had the cellphone mount for a few years but wasn't using it regularly. Also had a look at the GoPro's original mounts which came with the camera and the "tripod adaptor" which I'd recently bought online.

A 1/4" UNC screw (to suit the tripod adapter's 'socket')
A nut for the screw (not essential, only used if you have to cut the screw shorter)
A washer for the screw (doesn't have to be brass like mine, that just popped out of the junk box!)
A drill to suit the screw (5mm should be sufficient)
A piece of old inner-tube or similar soft, strong material

Scissors to cut the inner tube
Hacksaw to cut the screw (if necessary)

I first thought about fitting the GoPro quick-release base to the rectangular part of this mount, but that would be difficult and mean ruining the whole mount (the current 'project' is reversible).

So I decided to unscrew the existing threaded part and fit the tripod adapter instead. This means that if required the mount can easily be restored to its old state. Save the bits removed for later use (in another project maybe!).

This takes a bit of care (I split mine, but that's not a problem). Be careful that the drill goes through parallel otherwise you'll end up with a 'wonky' hole.
Overall the important thing is making the hole big enough that the screw can fit through.

The screw I found in my junk box was a bit too long for this application, so I had to shorten it by 5mm.
The photo shows how to calculate how much to cut off; the screw is fitted to the tripod adapter then held next to the drilled-out mount.
To cut the screw, first screw on the nut, and hold the screw/nut combination in a vice or other secure place. Cut the screw with a hacksaw (or angle grinder if you've got one - be careful!). After cutting try to take the nut off, this will help clear up the cut thread. If it doesn't come off, clean up the end with a file (don't think a vibrating sander will do it but you can try!)

Draw around the tripod adapter, then cut the inner tube to size with scissors (easy!) or a modeling knife (be careful!).

To cut the hole in the middle, fold the disc in half, then half again, then carefully cut the pointed corner off - about 3mm (1/8") is enough, don't want the hole too big!

Thread the washer onto the screw, pass the screw through the enlarged hole in the mount, then add the rubber disc and fit the tripod adapter.
Tighten the screw until the adapter doesn't move easily but don't over-tighten or you'll risk cracking something. If the adapter moves after mounting the GoPro, tighten the screw a little bit more.
Ideally, you'll want to be able to turn the adapter to make the camera face in the right direction but at the same time remain firm and not move when it vibrates.

Here's a photo of the "finished product", posing in true Pixar Lamp style!

This was my first Instructable, so I decided to do something simple "to get the hang of things". I hope you've enjoyed reading and hope that I've not missed anything. If you have any questions please feel free to contact me.

See you!