Jackson - the gift that keeps on giving. Floyd Rose problem.

Bod

So, following on from this thread - https://www.thefretboard.co.uk/discussion/228868/my-sons-ngd-and-a-problem, yesterday was the day my son's new Jackson V got extra special attention from the luthier.  All frets levelled and dressed and plays like a dream sans buzz.  A big shout out to Danny at Leicestershire Luthier for the work - I can thoroughly recommend them!

However, there's a problem with the FR Special that has us all stumped;

Pull up and all strings return nearly a semitone sharp.  Push down and they return to the correct pitch.  This happens every time without fail - a pull up needs to be followed by a push down every time.

The trem plate blades and posts are in perfect condition and lubricated.  Nut is solid and the clamps are tightened with no slippage/movement when pressure is applied behind the nut.  Intonation adjustment screws are tightened correctly. Claw is also lubricated at the spring contact points.  The trem is flat, and we also tested it with it completely level from E to E.

Also, the stud inserts are not level. The bass side is slightly high in the cavity, where the treble side is recessed relatively deep into the body.  I guess that's standard to allow different degrees of adjustment to compensate for string diameter?

I have considered swapping the springs out to see if that helps, but it can't be them can it?

The prime suspect is the stud spacing which is approx 74.6mm centre-to-centre, rather than bang on 74mm.  Could this be the source of the problem?

hollywoodrox

Could it be that the strings really need a damn good stretching in? I go along mine with a cloth and stretch the. As far as is comfortable until they seem to hold tuning under severe bends .
I have mine dive only , I’m guessing the extra stretch from pulling up might be made less trouble with a good stretch . I’m not very technical with this stuff to be honest  but it’s an idea, good luck anyway , jackson are lovely guitars

ICBM

Check that the bridge block is not snagging on the cavity wall in the rear cavity.

PAL

Any trem is not perfect and will go out of tune because the strings deteriorate with sweat and being pulled about also depending on the actual trem and that is is an expensive one or an economy model . Lower priced trems use softer metal so wear quick ! EVH would change the little locking blocks on his guitar every 1/2 night to keep his trem stable.
I would suggest the lightest gauge for a trem  would be 10s I use 11-49 on my suhr & Prs DGT and no problems but I don't
dive bomb or go mad on my trems.

ICBM

PAL said:

Any trem is not perfect and will go out of tune because the strings deteriorate with sweat and being pulled about also depending on the actual trem and that is is an expensive one or an economy model . Lower priced trems use softer metal so wear quick ! EVH would change the little locking blocks on his guitar every 1/2 night to keep his trem stable.
I would suggest the lightest gauge for a trem  would be 10s I use 11-49 on my suhr & Prs DGT and no problems but I don't
dive bomb or go mad on my trems.

Floyd Roses work best with lighter gauges. Almost all players using them (in standard tuning) will be using 9s or 10s, some 8s, very few 11s.

Any half-decent Floyd, even cheaper ones, works perfectly well once adjusted properly and locked down - if it's consistently sticking anything like as much as a semi-tone out, something is catching where it shouldn't. It's *just* possible it's some sort of problem with the knife edges, but unlikely if it doesn't do it in the down direction. Likewise, if it doesn't do it on a down-bend it isn't going to be the nut slipping on its shelf.

Misaligned (by height) stud inserts are not ideal but shouldn't be the cause.

From experience I would guess that the block is just touching the cavity wall somewhere when pulled up beyond the rest position - sometimes it can be quite hard to see, it can be as little as a bit of routing burr sticking out.

Bod

Thanks all.  I'll check the cavity later today and report back. It's a brand new guitar and has had new strings fully-stretched as part of the pro setup, in so I don't think strings or knife-edges are the issue.  Danny did notice that some of the chrome had come away on the posts, but he cleaned that up and lubricated and all was fine.

It has 10s installed and I think I'd need to add additional springs to balance the trem in standard tuning with anything heavier?

ICBM

Bod said:

It has 10s installed and I think I'd need to add additional springs to balance the trem in standard tuning with anything heavier?

Usually, yes.

Personally, I wouldn't use heavier than 10s unless you're tuning down, in which case three springs is still fine. Knife edge wear has been a noticeable problem on Floyds I've worked on with excessively heavy strings.

andy_k

Sometimes these things need to wear in, and then there is a window before it wears out.
I would suspect the problem was at the nut, but you say you are sure that is solid.
I have the problem the opposite way, have to pull up to get the strings back in tune, and I think that was more related to wear on the posts.
My final suggestion would be to check the springs are absolutely and perfectly balanced, which is a bit trickier on 10's, and I find it can feel stiff with this gauge, maybe go down to 9's and see if you can set it up so that it flutters, or warbles, rather than just doing divebombs, usually this will be using 2 springs fairly stretched out.
At least this would maybe isolate the springs as the problem, it is a fine balancing act and if nut and posts are in good shape the only other thing that is changing under tension is the springs.

Bod

OK, so I've had time to fully remove the tremolo and check everything.  There's nothing snagging the trem or trem block anywhere and everything looks perfectly in order. 

The only thing left that could be causing a problem are the springs themselves or the issue with the post spacing, in my opinion.

StormshadowGuitars

If there's no snagging of the bridge on the edges of the rout, block against anything or the arm socket underneath, then you need some new bridge posts in it, that's a classic sign of worn posts.
Sometimes you can't even see they're worn, although sometimes you can see a gold colour through the finish in the V where the bridge plate sits. 
Usually it's caused by 30 years of diving but in most cases on new guitars its a post(s) which aren't correctly hardened or not even hardened at all. They wear very quickly by winding up and down under tension to achieve the desired action if they're not hard enough. 

Get some proper Floyd Rose or Schaller ones, measure where the V is on your original posts (before removing) in relation to the rout or steel bush in the body with an accurate steel rule, then fit the new ones with the V at the same heights. 

Touchstone Tonewoods usually have them in stock.

Bod

So, we have some success.  I ordered a set  cheap springs to test with which I fitted and the guitar now returns to pitch from both directions.  They're slightly higher tension so I needed to back out the claw a little, but so far it seems the problem is solved.

ICBM

Bod said:

So, we have some success.  I ordered a set  cheap springs to test with which I fitted and the guitar now returns to pitch from both directions.  They're slightly higher tension so I needed to back out the claw a little, but so far it seems the problem is solved.

Are the old springs plated? I have come across springs a couple of times where the plating seems to have separated from the spring itself so there’s a ‘step’ in the travel as they extend or shorten. It’s very rare but it’s the only thing I can think of that would explain them sticking in one direction and not the other, if changing them has fixed it.

Bod

No, they're not plated and I agree that it's odd.  It is, of course, likely that something else was inadvertantly overcome during the process of swapping out the springs, but I can't imagine what.