The Powered Ground Board

Are you getting strangled by a dozen cords from the battery to heaters, video cameras, dob drivers, etc.? Does your dob starts looking like a May pole as it winds up the cords? How can this be reduced? How about 1 power feed that doesn't rotate and can even be placed under the tarp that your dob is on? Here is how:

1. Start with a piece of copper clad circuit board. Rad Shack sells it in various sizes and you can probably score bigger pieces at your local ham fest.  Saw out roughly a 4"square.  Find the center of the piece then mark concentric circles that will form the contacts around the pivot bolt. You can mask and etch it or as I did put it on a rotary table on the milling machine.

It works best to drill the bolt hole last to get it centered. Mount the contact plate on the top of your ground board.

Drill two holes down through the ground board for the incoming wires. Solder the wires to the plate.

Flip the board over and lead the wires to the edge. I used a piece of aluminum shelving bracket to protect the wires and serve as a base for the socket . Mount the socket and solder the wires on to the socket.

The next step is to make the contacts from the rocker box to the ground board. I used the brushes and mounts from an old trashed motor that was waiting to provide the needed parts. (Never throw out perfectly good junk, you never know when it will come in handy. This piece only waited about ten years.) You could also take the radical move of purchasing brushes or use something else to provide contact. What ever you use needs to be able to keep contact when the scope moves. I like brushes because they are spring loaded and keep good contact.

I drilled holes in the rocker box that would line up with the contact paths on the ground board. Just measure over from the bolt hole and drill. I then sawed out the hole to fit the brush mounts and epoxied the mounts into the holes.

Lead the wires on the brushes to a junction where you can tap the supply to wherever you need the juice.

You will of course do a neater job than I have.  If you set up your scope on a tarp and run the power from your battery through a hole in the tarp next to the socket on the ground board, you wont be tripping over wires or winding up your dob with wires as you spiral around the sky.

Build more stuff

Ed