CV Jag won't return to pitch when pulling up on trem

[Voiturefeml]

This my first guitar with an offset trem and I've been using stuff I've learned to set it up from Mike Adams channel and I've gotten it to return pretty much perfectly in tune when I do dive bombs or whatever, but whenever I pull up on the arm even by the tiniest amount and it goes sharp.

I don't hear any pings, I lubricated the nut and I did a little bit of sanding on the little plate of the trem because there was some clicking and it was getting stuck but it still goes sharp.
This is my first time messing with an offset so I don't know if I'm missing something or if the trem is just too cheap to get it to get it to work properly or whatever.

[GilmourD]

So, how high up is the bridge and is it centered/standing straight up when not using the trem?

[timtam]

It's possible that tuning instability with trem use can be due to the bridge, the trem itself, or the nut.

TL;DR: considering the bridge first, how high is it ? (a side pic would help). [this post written at the same time as the above post, which cuts to the chase]

The key to stable tuning of the freely rocking bridge is sufficiently high string-saddle friction. That is achieved by sufficient string-saddle downforce. And never lubricating the string-saddle contact points.

That high friction means that the strings never lose grip on the bridge - it always rocks all the way forward and all the way back with trem use. And remains in the neutral/middle position at other times.

Sufficient string-saddle downforce comes from a suitable combination of string tension (gauge) and string break angle over the bridge (the break angle sets how much of the string tension is "seen" by the bridge as downforce). If one of those two is high enough, the other need not be so high.

How high is your bridge ? (a side pic would help); that's what sets the string break angle (and why tapered neck shims are often used to get the bridge higher and thus increase the break angle). And what string gauge do you use ? (Fender usually ships both jags and JMs with 10's - which means that the jags have lower string tension, due to their shorter scale length).

If the bridge rocks well, but pulling up on the trem still comes back sharp, a nut slot is perhaps less likely to cause that. The string is pulled forward through the nut slot during the trem pull-up as it is stretched by the trem; then as the trem comes back down the string has to slide back through the nut slot. If the trem comes all the way back down to where it started, but the nut slot is impeding the string from sliding all the way back freely, the main length of the string will end up slacker than it should be, ie flat, not sharp.

On the other hand, if the nut slot is fine but the trem returns after the pull-up to a position short of where it started, then there will be persistent extra tension on the string, ie it will be sharp. Better made trems should be less subject to such problems.

[Voiturefeml]

https://photos.app.goo.gl/gobAa5w9tP5L6H9b8
I don't really have a good way to measure the height but it's close to 4mm.
I don't remember exactly what gauge the strings are but I think they're 11-52

[timtam]

Bridge height looks good. And that break angle combined with the string tension of 11-53 on the 24" scale should get you good string-saddle downforce (friction).

[GilmourD]

https://photos.app.goo.gl/gobAa5w9tP5L6H9b8
I don't really have a good way to measure the height but it's close to 4mm.
I don't remember exactly what gauge the strings are but I think they're 11-52

Bridge height looks good. And that break angle combined with the string tension of 11-53 on the 24" scale should get you good string-saddle downforce (friction).

I agree with timtam. It looks good.

With regards to the nut, did you do anything beyond lubricating it? If the slots are as they were cut from the factory you're likely in need of widening them a touch.

[Voiturefeml]

I widened them to fit the higher string gauge. I think it originally came with 9s

[gibs]

Wonder if it’s the knife edge of the trem, I wonder if the contact point is too squared off and causing issues when pulling up.

[michaelsegui]

On mine I sanded it more aggressively to resemble this:



It works much better now

[GilmourD]

On mine I sanded it more aggressively to resemble this:



It works much better now

I unfortunately don't have a belt sander but I have a really flat sanding block and a somewhat steady hand. All of my import trems have gotten this part cleaned up since they're die-cut from the factory and tend to have a haphazardly shaped leading edge.

[michaelsegui]

I used a bastard file and a steady hand.

Followed up with some 400 then 600 grit even though I probably didn’t need to

[Voiturefeml]

When I took mine apart it looked nothing like that so that might be the cause

[timtam]

Fender sometimes seems to forget that the end of the plate wasn't square in Leo's original patent ...