PLEKing a multiscale guitar

If you had asked us a year ago if a multiscale guitar could be PLEKed, we would have said “Not yet!” The PLEK machine was designed for parallel frets, and for many years doing a PLEK job on a multiscale (or fanned fret) instrument simply wasn’t possible. But the good people at PLEK are always working towards building a better mousetrap, and they have recently rolled out new software that allows for multiscale fret leveling. Let’s check it out!

We often say that the PLEK ain’t an E-Z-Bake oven – you can’t just throw a guitar in there, press a button, and expect good results. The PLEK is a precision tool, and a tool needs an experienced tech to utilize it properly. Simply buying a PLEK will not turn you into a guitar tech, much like if I were to buy a Ferrari Formula 1 race car would not turn me into a championship driver. PLEKing a multiscale guitar really exemplifies where computer controlled tech meets human skill.

This lovely BC Rich multiscale guitar came in with the usual problem that all guitars have – uneven frets, which were causing buzzing and dead notes. (Frets that are uneven by as little as .1mm can cause these problems.) We calibrated our PLEK to handle multiscale instruments, then loaded the guitar into the PLEK, programmed the guitar’s specs and setups parameters into the computer, and scanned the neck.

While the PLEK’s hardware is perfectly capable of scanning multiscale guitars, the hardware to cut the frets wasn’t designed for angled frets. The cutter wheel has three concave surfaces on a blade wheel, intended to crown and cut parallel frets in one efficient process. It spins at around 30,000 rpm and moves sideways across the fret as it cuts. Ours looks like this:

As you might imagine, these shapes aren’t conducive to cutting an angled fret. However, the geniuses at PLEK realized that the tips of the concave shapes are also super sharp, and so they created a program that cuts the frets using just the top edge of the cutter wheel. This is a slightly different process than usual, and the PLEK cuts the frets in an up-and-down motion, rather than side to side.

This was a great workaround, but it does come with some caveats: the frets aren’t crowned during this process, leaving the tops flat.

The frets need to be crowned manually, to remove the PLEK’s machining marks and return the fret’s tops back to round. This takes a great degree of skill – remove too much material and you’ve undermined the PLEK’s quality, too little and the string will grind on the machining marks and will feel unpleasant. (This is why we feel that unless you have a lot of experience in fretwork, you really have no business buying a PLEK.) We’ve done thousands of fret jobs prior to receiving our PLEK machine, so crowning these stainless steel frets were a piece of cake.

To crown the frets, I use my trusty 15 year old StewMac diamond file, which has been worn down to the perfect level of dull for my tastes. (I’ve tried replacing it, and the current iteration of the StewMac file isn’t nearly the quality of my old one – so I’m sticking with what I’ve got!) While I usually just eyeball the frets as is, for the sake of making it easier to see in pictures I’ve marked the tops with a red marker.

The trick is to crown the frets evenly, and removing the shoulders until there’s just a fine line left on the top. It sounds easy until you try it! Even I really agonize over the process, all these years into it. The PLEK is accurate down to .1mm, and I don’t want to blow it!

It’s a time consuming process, especially with stainless steel frets, and every fret needs to be as accurate as the last. It’ll definitely wear out your elbows and wrists (and patience!), so it’s a good thing I don’t have to do this terribly often. But everything turned out great, and once the frets were crowned, I polished them to a mirror shine and was ready to give the guitar a complete setup.

Every time we PLEK a guitar, we program the setup parameters in for each instrument, so the setup accuracy is crucial. Different setups, string gauges, and tunings require a distinct PLEK programming – it’s not a one size fits all process. We have very specific guidelines for our setup procedure, so every guitar is setup exactly to the player’s requests. I set this guitar up for what we call super low action (1.25mm-1.00mm, from low string to high), and it plays perfectly with no buzzing or fretting out. Hooray!

If you’ve got a multiscale instrument and are having problems with string buzz, poor sustain, and notes choking out, and have been frustrated that your guitar previously couldn’t be PLEKed, come see us!

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