Re: Lowering Floyd Rose nut
I thought I would offer an update on this thread.
Just received the FR 1000 Pro with R3 nut (1000s are the only ones available in satin chrome).
It is extremely similar to the JT580LP. The only difference is the JT580LP's baseplate extends backwards slightly near the Jackson logo, whereas the FR1000 Pro is straight. Also the JT580LP's saddle blocks are beveled on the edges, whereas the FR1000 Pro is not. They are so similar that the JT580LP's arm will screw onto the FR1000 Pro.
The FR1000 Pro is much heavier, I'd say by as much as half again or perhaps a third more than the JT580LP. The knife edges are much sharper and thinner than the JT580LP. Although mine is about 16 years old, I did not use the whammy extensively due to tuning issues. Sharpening the knife edges on the JT580LP may have solved some problems, but I think getting the edges as sharp as the FR1000 Pro's by hand would have been difficult.
The block on the FR1000 Pro is much heavier than the iron Takeuchi block on the JT580LP. After looking at pictures, Adam Reiver at FU-Tone suggested that my block might be the problem with the lack of flutter (naturally), but he also noted that the block screw holes in the bridge baseplate of the JT580LP would have to be bored larger to accommodate most upgrade blocks.
A problem I had forgotten about in the original post is removing the bridge post bushings, which would require a special tool, as well as possibly heating the bushings to loosen them and scouring around them (I thought mine was the old wood screw type). The JT580LP screws measure about .230" in diameter, while the FR1000 Pro is about .270". Interestingly, at the post where the knife edge makes contact, the JT580LP is about .002" thicker than the FR1000 Pro, so my concerns about the bridge pivoting on too small posts may be unfounded.
That said, the shape of the posts differ. The JT580LP tapers much more gradually to the knife contact point, whereas the FR1000 Pro's posts cinch in rather quickly, like a corset. I don't know what effect this will have on flutter and tuning stability, but I do not think it is worth removing the bushings over. I tried the FR1000 Pro's posts in the JT580LP's bushings and they will not fit.
The nut is much higher as well. Measured in the D string trench with a digital caliper, it is .280", whereas the JT580LP nut is about .233". It is difficult to be sure because the import nut trench tapers to a V point so thin that even a caliper blade won't fit all the way to the bottom, whereas the FR1000 Pro nut trench ends in more of a U shape with a flat bottom. The FR1000 nut barely fits in the nut slot. Dr. Newcenstein was also correct when he stated that OFR nut clamps are too large for import nuts.
Even if a new nut isn't necessary and one goes with better quality saddle blocks for increasing tuning stability, I think the blocks for OFRs are slightly too large for import saddles. So you need new saddles to go with your new saddle blocks. Most likely, new saddle blocks use larger screws, requiring enlarged holes in the baseplate or praying that the smaller import screws will hold everything in place.
Why the size difference? I assume to make the bridges more cheaply. Going to the next size down in common machining measurements probably saved money on the bridge by cutting down by .04" or about 3/64" here and there. I can understand this difference between metric and imperial measurements, but it seems odd considering that OFRs are made to metric specs. In all cases, more metal gave a superior weight and feel, save perhaps with the trem arm, which seems almost identical to the FR1000 Pro. Perhaps most telling is the quality of the string claw, which is much, much heavier in the FR1000 Pro than the JT580LP.
Per the advice of a knife smith (whom I assume spends most of his days grinding metal), I will attempt to gradually lower the nut with sandpaper that works on metal.
So, to sum up, would it have been worth it to keep messing with the old JT580LP bridge? Although several solutions here probably could have saved me from buying a new bridge, I'm not sure they would have been worth it and, by the time I paid a machinist to make the necessary alterations AND purchased a heavier block, it probably would have cost the same to buy a new bridge.
Consider that the knife edges would have needed to be sharpened, something that would have been difficult to do accurately by hand, and that the base plate block holes would have had to be enlarged. Consider further that the nut could have been causing a problem and it would have to be replaced regardless of sanding the blocks due to the softer metal giving around the strings (or the sanding also removing material from the blocks, permitting more string movement and thus decreasing tuning stability).
What I have learned from this is, without machining and woodworking tools, it's a better idea to buy a guitar with an OFR bridge than to try and upgrade an import. The problem is American-made or premium Japanese guitars with nice quality hardware have largely been replaced by cheaper Japanese, Korean, Chinese, Indonesian, and Vietnamese imports on used gear sites and in retail stores. Even if you find a nice American made model used (I'd pay about $1200-1500 at most), there's no guarantee the knife edges on that used guitar will be in good shape.
So, it's a crap shoot.
I'll post more when I've set everything up.