I have some truss rod questions concerning the slot for the rod - what shape (profile wise not from the top) is it supposed to be?
I have scrounged the internet looking for info on what the correct way for it to be shaped or which type of slot to use with what type of rod, but have found no useful information. The main three types of channel slots that I have thought of are:
B. sloped downwards from the guitar to the nut and
C. parallel to the fretboard.
However, I haven't been able to find an example that shows the profile and states which type of rod to use for each instance. AND which instance should be used for each type/size of guitar?
Which type of slot should I use for a traditional styled rod in a 25" scale guitar?
thank you in advance
duplicate post ....
Well, I will contribute my .02 cents, since this is also something to which I have given a deal of thought.
If by "traditional styled rod" you mean a single action compression rod, then a straight slot, sloping downwards from the nut to the heel ( ie parallel to the back of the neck) is sufficient. I am well aware that some builders have set up elaborate jigs to machine a concave curved slot in the neck ...these efforts are wasted ...the single action compression rod works exactly the same in a straight slot as in a curved slot.
One thing worth mentioning is that the slot should ideally be machined with a round nosed router bit, and should not be just a bog- standard square groove.
Depending on the truss rod used, any section of the slot which needs to match a square profile in the truss rod can be shaped by hand, with a chisel.
Zeke which truss rod are you using - please be specific?
Get on the web and go to youtube with "truss rod channel" for a good place to start and then follow the links. Pictures are worth a thousand words here. There are hundreds of different truss rods and there are a lot of different ways to install and configure the rods and channels. Stewmac have a representative truss rod installation guide on their site under the "Free Information" side bar title. Lmii.com have a truss rod installation guide under the 'Articles and Tutorial" heading on their homepage. These are good places to start your reading and also view some of the usual suspects when it comes to truss rods. To get all this in one place go to the web and Google in "truss rod information" which has a ton of info.
FYI We use a round nose bit for all our channels and a square end bit for cutting the flat bottom rebates for the flat ends of various rods. Curved rod channels or inserted curved fillets take the rod from a compression rod to a leverage rod (which works better than the old compression rods from my point of view).