Magnetic attachment for smartphone

In order to use the  "Smart-tools" application  (see this article) in the shop, particularly for setting up  a tilt using the plumb line tool, I have built this magnetic attachment in order to hold the smartphone using a magnet :

Here is a use case, for setting up the blade tilt angle of a table saw :

Here, I compare the precision with an "angle box", which is a reliable digital protractor, with accuracy of 1/10th of a degree.

We can see that the accuracy of this particular smartphone is not completely great :  at  25°, it varies between 0.2 and 0.3°, compared to the angle box, and at 45°, the difference is  0.4°.

Here, the smartphone is a Galaxy SII. It could be interesting to have results from other models.

Anyway,for lots of applications, this level of accuracy can be good enough, however for precise jobs such as making miter cuts for segmented rings, it can be a little weak.

Do not hesitate to share your experience with other models !

Comments can be left here or on Facebook, or on HomemadeTools.net.

Christophe