Practical 3D Printing - Echo Dot Junction Box Mount
I have several devices (currently: lights, air compressor, air filter) that I can control in the shop via Alexa and use an Echo Dot (2nd gen) to do that. While my shop isn’t that big, I wanted to place the Dot in a central location so that the Dot would have the best chance of “hearing” me from anywhere in the shop.
I decided the ceiling was a good place, I could mount it in or near the center of the shop, and it was out of the way. I didn’t have power there though, nor did I feel like running power just for the Dot. However, there is a Ubiquiti UniFi AP AC Pro on the ceiling, and I remembered that it has a USB port on it.
The Echo Dot is typically powered by a 5v wall wart with a micro USB connector, so I thought maybe I could power it via the UniFi AP’s USB port. I did some digging but could not find any documentation to tell me what the specs for the port are. Ubiquiti currently doesn’t have a use for the port (it was meant to connect an add on speaker for their EDU model) and I’ve heard that current units of the AP don’t include the port. But I remember a Ubiquiti employee asking in the forum if anyone was interested in having the ability to plug a USB printer into the port. While that’s sort of a silly idea, it did give me the assumption that the port must be a standard port as far as voltage and current. Going on that assumption, I plugged the Echo in to see what happened and it worked just fine. The Dot requires 1.5 amps, which is in line with the USB 3.0 spec., and considering they (Ubiquiti) originally intended the port to power an add on speaker, and the AP hasn’t had any issues, or released the magic smoke, I figure they designed it to meet the USB 3.0 spec. which allows for 1.5 amps (note: the AP is powered by standard PoE).
Anyway, with power sorted I decided to mount the Dot to a junction box adjacent to the AP. And before you ask, yes, there is power going through the junction box, but it’s for the shop lights and is switched (via Alexa) so it would not work for powering the Dot. I modeled a simple mount for the Dot in Fusion 360 and then 3D printed it in PLA.
I’ve included the STL file below and also put it up on Thingiverse. I modeled the screw holes as slots to allow for variability. The Dot fits in very tight but there is also a small lip to prevent it from slipping out. Also, it’s deigned to have a gap between the holder and the junction box to allow the sound from the speaker to come through.