Hammer. Whang bar. Vibrato bridge. Rocking stick. No matter what you call it, they will detune your guitar if it’s not properly set. The main reason guitars are out of tune is because of the saddle – strings catch and bind there and don’t return to pitch. While a properly made nut made of bone or brass will make most people happy, sometimes you just have to take it to the next level and install a Fender LSR roller nut. The roller nut is a pretty ingenious device – the strings slide over it on ball bearings, practically eliminating any friction in this crucial area. There is a lot of risk involved in installing an LSR pulley nut, and you can really screw anything up if it’s not absolutely perfect. But since when do we shy away from terror?
Our friend Mark brought his Squier Strat, which he had put together during his quarantine period. He added a bigbsy vibrato, rolling bridge, and locking tuners and still struggled with keeping the tune up. He asked us to do a PLEK bundle level and setup and install a Fender LSR roller nut. When we saw the original plastic nut, we could see why he wanted an upgrade:
After we leveled the frets with our PLEK machine, I first removed the nut by tapping it lightly to loosen the glue, then pulled it up and out.
The Fender LSR nut is wider than most stock nuts and doesn’t just fit into the existing slot. The placement of the saddle is absolutely critical – if it is even slightly off, the entire guitar is out of tune. If the saddle is placed incorrectly, the guitar’s scale length changes, causing each fret to sit in the wrong place. This has to be done right.
Fender recommends cutting the leading edge of the existing nut slot 0.094 (2.38 mm) toward the first collar. I measured this carefully with a micrometer and marked my line.
This is where it gets tricky: I planned to cut this slot with some custom programming using our PLEK machine. We have the option to cut groove slots with the PLEK based on the scale length of the neck. But this guitar needed the groove slot in a different location so I had to get the PLEK to do my bid. I programmed the PLEK, told it the guitar was fretless, and used a dummy fret to reference it as a nut locator. I placed the dummy collar on the mark I had made, exactly 0.094 “(2.38mm) forward from the existing nut slot. The PLEK would now see the dummy collar and think the nut slot is further forward than it was for this scale length, and would cut it exactly 0.094 (2.38mm) towards the first fret. Yes, I may have lied to the PLEK, but I don’t feel bad about it. It’s a robot and has no feelings (yet!) .
Then I loaded the guitar into the PLEK and programmed it to cut the groove slot to the dimensions of the LSR roller nut. The PLEK uses a 2mm bit that rotates at 50,000 RPM to cut the nut slot.
The PLEK cut this slot in less than five minutes. It’s a neat cut and perfectly placed.
Now it was time to mount the LSR roller nut. I marked the holes for the screws and drilled pilot holes so the screws would sink in. We always drill pilot holes – this prevents the screws from breaking or breaking out and turning a 20-minute job into a 2-hour job.
It fits perfectly! I set up Mark’s guitar with a super low action, with LSR roller nuts so the strings barely go over the first fret. Now Mark can use that beat bar without worrying about his guitar going terribly out of tune. Brilliant!