3D printed mobile phone stand

24 Octobre 2016

When I looked for a stand for my bq Aquaris E5 mobile, I unsurprisingly found that there was nothing easily available and specific for that phone.

Hence I decided to build my own like many 3D printer owner do. All I wanted was something that could hold my charging mobile phone in a position that I could see the messages showing up as I'm working on my laptop.

The requirements then evolved into being able to listen to music, handle a hand free call and possibly in an orientation that would let the front video show my face as the phone is on its stand on my desk about a metre from me.

I first decided that I would need to test a simple stand without the charging so I could check that the phone sits nicely stable onto it. So I started to draw a very elementary stand to the dimensions of my phone. The only thing I knew about the charging function is that I would need a wire to get to the bottom of the phone at some point so I added an arch shaped hole to the foot of the stand so it could sit on the wire nicely. All I wanted to know at that point was if the arch would print nicely.

With that first print, I could validate that the stand could stand over a USB cable without problem and also that the front guard pressing the front face of the phone at the bottom was the right size to hold the hone firmly while not masking more than a couple of millimeters of the bottom edge of the phone. I decided that the side arms would not have a front guard so you could pull the phone out easily.
Another thing that was validated was the angle of the phone on its stand. I picked 15° not particularly scientifically but looking at the CAD model and comparing different tilting values. The 15° inclination gives nice viewing angles at an arm's length and my face is nicely in the field of view of the front camera, still it's not super comfortable to type messages as the wrist needs to bend back almost 90° in order to type. But it's still possible to send an occasional message and that wasn't the initial function intended for the stand.

So everything was functional for what I was testing but the stand wasn't looking very good, there was no possibility to connect a USB cable and the stand was clogging the vents of the speakers which are located at the bottom of the phone (where the phone sits on the stand).

So I came back to the drawing board with some amendments aiming at getting the stand fully functional on the second go.

First regarding the charging, I had to decide among different options : having a connector mounted on the stand or a cable ? straight or angled cable ? Glued or loose ?

After some tests, I decided that having a fixed connector wasn't such a good idea. These things are good when you have perfect tolerances and if it's not perfect, it's likely to harm the phone in the end. So I decided it would be a cable and an angled one so the phone does not need to be high above the surface of the table.

I got such cable from Amazon (https://www.amazon.fr/gp/product/B00ENZDN3Y/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1) and there are only two things to look after when you pick that cable :

The length of the cable (I found 1m was good on my desk)
The orientation of the connector (!!!). The cable must exit from the back of the device.

Once the cable is identified, it's easy to carve the stand so the phone plus connector can sit onto it without friction. I have taken advantage of that to also remove some unnecessary structure and round the link between to vertical and the horizontal parts of the stand to make it look nicer.

At that point, the last thing I wanted to modify was related to the speakers. I wanted to be able to open some sort of duct from the phone's speakers to the front face of the stand so the sound can be heard without too much attenuation.

So I carved out two pits underneath the speakers connecting them to a front grid.

At that point, the stand was complete. This design wasn't actually the second prototype, it was the third one. As a second prototype, I had designed pits with a more complex shape which turned out not to print nicely. So I had to redesign these and that next design was both simpler and more robust to print. That's to keep in mind for 3D printing : simple and understandable designs work best.

So here are the 3 prototypes :

Left is the latest one
Middle is the one with the printing problem on the front face
Right is the initial dimensions test one

Now let's have a tour of the final prototype.

So the USB cord stays under the stand and you first plug the connector into the phone before you slide it in. Since the stand is very light, it's always moving a bit during that operation but the nuisance is not enough for me to add weight to the structure.

Typically a phone stand is for apps that keep the phone awake like ambient sound, radios or alarm clocks.

But since I like also to use it to keep the text message stream displayed, I found that it was really nice in combination with that very simple app (Active-screen) which is available from the Ubuntu app store and lets you ask the phone to never lock the screen so you can follow any application for the time you want.

I have printed that model using Cura (which now works nicely with the latest bq firmware) directly printing on the Hephestos 2 using the preset "Low quality" profile. This profile might show the layers quite obviously but I would myself not really call it low quality, for example it shows less printing scars compared to finer layers. And in the end it's so much faster that for large objects it's the one to use at least in prototyping phase.