Defective Trussrod Wheel ?

Apr 26, 2015
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Hello,

I bought a new ATK810 and I noticed the trussrod wheel moves in and out along its axis. Although it does function properly (can adjust relief) I'm worried if that is going to give me problems in the future. Should I return the bass?

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That is, I assume, a double-acting style truss rod with a spoke wheel head. You can tell because the head is not up against the heel of the neck. Yes, as you turn the wheel it will thread in closer to and out further from the heel. That's normal operation, nothing wrong with it. You may not notice it on most instruments because generally, you are only turning the wheel maybe a quarter of one turn when adjusting the relief. But if you turn it all the way through from forward to reverse, you'll see the in and out movement.

Now, on older single-acting truss rods with spoke wheel heads, it's different. The whole nut and wheel bears against the heel when the rod is tightened up. Usually, the wheel is up solid against the wood. Tightening it, you shouldn't see it move laterally. If you loosen it, it will just unscrew and come out.
 
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I think he means the wheel SLIDES in and out freely as if the anchor end is loose, not that it moves in and out in the threads.

Correct, it slides in and out without turning the wheel

I am not sure I understand what you are saying. Is there a wobble in the wheel? If it moves closer or further from the end of the neck, I am pretty sure it is supposed to.

No wobbling at all. But the movement along its axis is completely free ie turning the bass upside down it moves in and out.

I have an ATK305 and it doesn't do that. I would pull the neck and see how the wheel attaches to the truss rod mechanism. Maybe it attaches with a bolt through the middle and it has become loose or is missing.

I might try removing the neck today and see what's inside
 
It's behaving exactly as it should. No worries.

That is, I assume, a double-acting style truss rod with a spoke wheel head. You can tell because the head is not up against the heel of the neck. Yes, as you turn the wheel it will thread in closer to and out further from the heel. That's normal operation, nothing wrong with it. You may not notice it on most instruments because generally, you are only turning the wheel maybe a quarter of one turn when adjusting the relief. But if you turn it all the way through from forward to reverse, you'll see the in and out movement.

Now, on older single-acting truss rods with spoke wheel heads, it's different. The whole nut and wheel bears against the heel when the rod is tightened up. Usually, the wheel is up solid against the wood. Tightening it, you shouldn't see it move laterally. If you loosen it, it will just unscrew and come out.

Sorry, I meant it slides in and out without turning the wheel.
 
OK, I removed the neck. There is a hex-socket-head trussrod, then a hex rod about 1" long and then the wheel which is a hex socket key. I removed the wheel from the rod and put it back again and now is tight in position. Couldn't figure out why the wheel was loose along its axis but anyway problem is fixed, trussrod works fine, bass is setup and ready to play.
 
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Huh. Well, that's new to me, a design I hadn't seen before. So the wheel is a separate part that slips onto the hex end of the truss rod, and tightens with a set screw on the side. In your case, the set screw had come loose and the wheel was sliding on the hex. Interesting.
 
Huh. Well, that's new to me, a design I hadn't seen before. So the wheel is a separate part that slips onto the hex end of the truss rod, and tightens with a set screw on the side. In your case, the set screw had come loose and the wheel was sliding on the hex. Interesting.

No, I was thinking that maybe there was a loose set screw because although it was moving in and out I was able to adjust the trussrod. Then I removed the neck and saw this.
I only removed the wheel, put it back (probably in different angular position) and now is tight.
Edit: the hex socket key is actually one part ie the wheel.

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Oh, I see. That's even funkier. They made up a two piece adapter to convert a normal style truss rod into a spoke wheel rod. Okay. I'd be a little concerned about the parts vibrating loose and rattling. If that's a problem, you could lightly glue them together with a drop of blue Loctite. That may be what they are doing from the factory, and yours just broke loose.
 
Oh, I see. That's even funkier. They made up a two piece adapter to convert a normal style truss rod into a spoke wheel rod. Okay. I'd be a little concerned about the parts vibrating loose and rattling. If that's a problem, you could lightly glue them together with a drop of blue Loctite. That may be what they are doing from the factory, and yours just broke loose.
WOW! New one to me as well. Don't know what I think of it - it's clever, but may be problem prone.
 
Oh, I see. That's even funkier. They made up a two piece adapter to convert a normal style truss rod into a spoke wheel rod. Okay. I'd be a little concerned about the parts vibrating loose and rattling. If that's a problem, you could lightly glue them together with a drop of blue Loctite. That may be what they are doing from the factory, and yours just broke loose.

Here is a picture. Another thing is that the assembly is not concentric with the neck hole and couldn't tell if it is the rod part or the whole trussrod.

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@tzohn , nice drawing! :thumbsup:
It's a photograph. Oh, you mean the post before the photo..... yes, nice.

I wouldn't be concerned about the fact that the end of the truss rod is not in the dead centre of the hole in the neck. Pretty common for them to be off a bit. And from the appearance of everything I don't think that there is anything to be concerned about except that the wheel may rattle on the truss rod extension. A bit of loctite as Bruce suggested will probably handle that just fine.
 
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