Mount Power/USB distribution hub

Looking at my setup I was always concerned about the number of cables and how they hung off my Orion 190mm OTA and the iEQ45 mount.  Major concern was having a cable snag and rip something out.  Also was some concern that it might be affecting my tracking/guiding.  So I did some searching but references were sparse.  Posed the question on Cloudy Nights  and got some excellent advice and information.  In addition Rudy posted on flicker what he had done in combing the power and USB so that only two cables ran up the mount.  I also found a page on cable organization that provided some good information.  This seemed like a great idea so over the holidays I set out to do the same.

First step was to plan how and what I was going to support.  If I was going to collapse to just two cables, (power & USB) then I needed to support the following out of the hub.

  • 3 USB connections - DSLR, focuser, & guide camera
  • Needed to supply 5v for USB hub.  In past testing a non powered hub would not support the DSLR, guide camera etc. so  need to supply power for a powered hub.
  • Also need to supply 7.5-8v for the DSLR
  • 12v connections for dew, fan, etc.

I ordered two power converters off of eBay.  One is a 12v to 5 v, 3A and the other was a 12v to 7.5, 3A.  I put these into a 5x2.5x2 project box from Radio Shack.  Also used a cigarette lighter adapter from Radio Shack for the power connection.  Issue is it is only 18 awg wire and I will probably have too great of a voltage drop when I want to also power the camera cooler I am building and the dew heater.  So at some point I will probably upgrade this to at least 16 awg wire.  This is the reason for using the wire nuts instead of soldering those connections.

I chose a Kingston 4 port USB hub.  One nice feature is the case is aluminum and so I was able to drill holes in the ends to connect it to the top of the project box.  I did this by first removing the circuit board, (easy to do), so as not to damage it.  After updating drivers I was able to verify that everything would work with it.  I also discovered that some USB cables worked better connecting to it than others.  So if you have issues with your hub try changing cables.

I used four RCA type plugs for the dedicated 12v connections and a mini phono plug for the camera power supply.  I took a Canon power adapter that inserts in the battery bay and cut the non-standard plug off and soldered in a mini phono plug.