I have always bought my truss rods from either Martin, LMI or Stewmac. Standard Martin Style rods for neck with 14 frets at the body. Now when using one of these rods the rod would run from about 1 inch from the nut area to about 3" beyond the heel. Short enough that the rod doesnt actually go through the hole in the brace but works well.
Recently I bought a couple of rods from eBay which are 18 1/4" length and offered as Martin Style rods.
They seem much too long and I ended up shortning them and then routing the channel all the way into the headstock and still had to shorten by a couple inches.
When using these rods, I ran the rod so the one end went into the headstock and the adjusting nut went into the hole on the soundboard brace. This caused some problems because the space between the fingerboard and the rod is very small and had to thin the soundboard a little to make it work. Never had this problem with the Martin shorter rods as they fall short and slotted the soundboard to the extent there was never any conflict with the rod
Martin channels run shorter. Here is a picture from John Hall's eBay auction for necks to show a Martin neck, the channel and the rod. You can see by the picture the approx size of the truss rod in comparison to the channel.
So now the questions:
When you guys/gals install a truss rod, how long of a rod do you use and how long is the channel in the neck? Do you run your truss rods all the way through the hole in the soundboard brace or do you keep it shorter?
The rods on ebay are a good price ($18 for 2) but when you have to shorten them up it is not a great value for the small savings.
