The Sharkfin Shall Rise Again.....

[dubtrub]

I agree with all of this HOWEVER Gibsons truss rod construction is similar. They have a compression rod which is mearley a straight 1/4" rod with an anchor at the heel and adjustment nut at the head and they use a filler strip to keep everything tight.

Kevin, could you provide a photo depicting a Gibson truss rod as you described? Mechanically that make no sense. Merely tightening a straight rod in a straight channel should not cause a bow or back bow which is necessary for adjusting a neck. An upward or downward pressure to resistance would be needed. Unless I'm losing my marbles.

This is the only way I can see a single rod working properly for bow.

[KRamone27]

I agree with all of this HOWEVER Gibsons truss rod construction is similar. They have a compression rod which is mearley a straight 1/4" rod with an anchor at the heel and adjustment nut at the head and they use a filler strip to keep everything tight.

Kevin, could you provide a photo depicting a Gibson truss rod as you described? Mechanically that make no sense. Merely tightening a straight rod in a straight channel should not cause a bow or back bow which is necessary for adjusting a neck. An upward or downward pressure to resistance would be needed. Unless I'm losing my marbles.

This is the only way I can see a single rod working properly for bow.

I agree with it not making sense mechanically but here is a video of a 1959 les paul junior in a cat scan showing the inside of the neck. Not saying this is representative of all models just recording my findings.

Found a pic

[dubtrub]

It's an illusion. Searching the internet for Gibson truss rod, it is a single rod in a curved channel. Apparently the Gibson curved channel is not as exaggerated as on the Fender.

[KRamone27]

After doing some more research you are right Danny I apolagise. I found this page explaining it http://theaccidentalluthier.blogspot.co ... s-rod.html Sorry to hijack the thread Aaron.

[oipunkguy]

thanks for the advice danny. this is the first time Ive ever used a rod like this. im not 100% sure if i'll have an issue with the rod or not. I'm use to using the two way rods. I glued in a small block and the headstock to keep it tight and i did the same at the other end, i think I'll just have to test it before going any farther. even though I got the rosewood glued on, removing it would be a lot easier now then after its all finished. I'll test it out and let you know what my finding are. on the pickup i plan to use 44 AWG wire, and try to wound it to 20k. we'll see what happens lol

[oipunkguy]

no problem guys, i just followed the instruction that came with the rod from stew mac. i dont remember reading anything about making the channel arched but it makes sense. I 'll go back and look again. i know one mistake I made is i placed the truss rod nut higher then i probably should have. again ill look and see what i find. thanks for all the advice.

[oipunkguy]

here's the instructions stewmac provided for installing this type of truss rod. what am I missing?


1. The truss rod should be installed before the fingerboard is glued onto the neck. Sand the top of the neck flat and cut a slot 3/16" wide and 7/16" deep, down the middle of the full length of the top of the neck. Use a table saw or a router.

2. Locate the truss rod so that the adjusting nut and washer, and the fixed "barrel" anchor nut, are at the locations shown in the diagram. Some mandolin necks may require the adjusting nut closer to the string nut, for proper placement of the plastic truss rod cover. Mark the positions of these locations on the top of the neck.

3. Drill a 3/8"-diameter hole, 5/8" deep for the barrel anchor nut.

4. Widen the slot cylindrically at the peghead, to form a 1/2"-diameter channel. This will allow access to the adjusting nut and will let the truss rod fit freely into its slot along its entire length. Wrap a bit of masking tape around the center of the rod to prevent rattling.

5. Prepare filler sticks of matching wood to cover the truss rod and the slot beyond the anchor nut. The filler sticks should fit snugly but should not be forced in too tightly. Glue them in place and clamp while drying. Don't get glue on the rod or the threads. When dry, sand the top of the neck flush again, and install the fingerboard and peghead overlay. Cut through the overlay for access to the adjusting nut.

6. The truss rod is adjustable with a 5/16" socket. Turning the nut clockwise will help correct an upward neck bow when the strings are tuned to standard pitch. The rod is designed to keep the fingerboard playing surface in the proper plane. Raising or lowering of the string height should be done at the bridge.

[dubtrub]

Those instructions are not real clear. I'm assuming step number five referencing the 'filler sticks' is meant to push the 3/16 diameter rod down into the 7/16" channel creating a curve to the rod. That would imply the filler stick would be 1/4" X 3/16" X (?) long. A quarter inch downward bow on the rod inside the 7/16" channel would give the rod the correct amount of bow as long as the filler stick was only about 6-8 inches long or else curbed the full length. The problem I see is there will still be a lot of open space on the bottom side at each end of the rod. This can create all kind of unwanted problems especially with rattling noises.

[oipunkguy]

well i tested the rod last night and you sure were right Danny, it didnt work. so here's the plan to fix my problem. I'm going to remove the fretboard and install a two way rod. if the channel I routed it too big then I'm just going to clean it up by routing it out more and then glue in a new piece of maple. once that's dried recut the channel for the new rod. oh well. I'm not complaining its a good lesson to learn, it's just too bad danny didn't checked the thread a few days earlier before I glued on the fretboard, lol.

[TerryTNM]

Hey guys,
Hadn't seen this thread before. Looks like the truss rod discussion has been sorted out. The curved trough has been Gibson's preferred method from the beginning.When I first started making guitars I to thought that all that was required was a straight rod in a straight channel.

There seems to be at least two benefits from that type of rod installed properly. 1. there is some adjustment to the neck bow and 2. because of the internal tension between the straight rod in the curved slot and the tight fit it seems to make the neck stiffer than using a loose fitting 1way or 2way.

That's been my observation anyway. I've always admire picking up a gibson and giving the neck a back pull to see how stiff they are. I still use the 2 way though.