Wire ProtectionThe wires and cables on these machines need to be supported so they will not snag or be cut by the motion of the axes. 
A simple option uses a spring and dowel to hold the wire. The arrow in the image points to the spring which is inserted into a hole that is drilled in the end of the gantry. A dowel is inserted into the spring, and the wire is clipped to this mast. This holds the wire above the machine while allowing it to move with the carriage. The wire is attached to the top of the carriage and to the end of the gantry. The wire should not be allowed to flex where it exits the stepper. Cable clamps made from thin metal tie the wire to the carriage, and route the wire so it will not fatigue as the mast bends. ...........
 The next system uses a strip of plastic to support the stepper's cable. The plastic is a nailing strip that was cut from a piece of vinyl siding J channel. Banding strap also works well as flexible guide. The plastic holds its shape and prevents the wires from falling into the work or kinking.Zip ties hold the wire to the plastic; they are loose enough to allow the wire to slightly shift as the plastic straightens.  One end of the strip is screwed to the middle of the top of the gantry, and the other is attached to the stepper. ...........
For heavier wires or longer spans, the wire can be attached to rods which are held together
with springs. The rods and springs hold the cord above the gantry and permit free movement. The rod to gantry attachment permits the rods to swivel, as shown in the lower image. 
This base is made of soldered together copper pipe and flashing. The cables are held to the table with basic cable clips made of thin sheet metal such as a drink cans, aluminum flashing or siding coil stock. The power cord for the router spindle plugs into an extension cord which is permanently attached to the gantry. This permits the easy exchange with other tools. ...........
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  This homemade cable carrier was made by dadoing a 2x4 which had been ripped to 3 inches wide. 
The wood was cut into sections with 5° ends. A strip cut from a piece of vinyl siding was screwed to the bottom
inside of the channel.
The carrier is attached to the gantry and rests on a ledge on the side of the table. ...........
The
servo and encoder cables were originally bundled together as shown on the right, but this
caused encoder problems. The symptom was the inability of the machine to hold position. The servos moved but the motion was erratic.  The encoder wires were then replaced with shielded cable, and they were run on the outside of the cable carrier as shown in the bottom photo. This eliminated the interference. Another option builders have used is clamping ferrite chokes around the cables. |
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