Having our PLEK machine for several years now, we have been asked a ton of questions about how it works, why no human can ever do a better job than PLEK, why would you need it on a new guitar, where are the lasers, and more.  Here is a good breakdown of PLEK and why you may want to consider it for all of your guitars!

What exactly is a PLEK and how does it work?

A PLEK machine is a specialized CNC that is used high-visibility, high-accuracy work on guitars.  With a tolerance of 1/1000 of a millimeter, this tool allows for extremely precise work.  The primary function of PLEK is to level and crown the frets on an instrument but it actually does much more.  Being a tool, the PLEK is only as good as its operator.  Here is an example of how a fret level and crown process looks like:

  • A large amount of data about the instrument is fed into PLEK to give some references to measure from (amount of frets, fret width, distance from nut to first fret, ect...)
  • PLEK scans the instrument with the preferred strings on and tuned in the way the player tunes ultimately scanning underneath each string taking a full reading of the fretboard and each fret.  This produces a virtual map of the entire playing surface of the guitar including every point of every fret that is touched by a string along with nut slot height and action.
  • A visual representation is displayed allowing the operator to see all the data points.  At this point the operator will make adjustments to the instrument to get it as close to perfect as possible.
  • At this point, 2 things can happen:
    • The guitar is able to be adjusted within tolerance and does not need fret work.  It leaves PLEK and goes to the floor for setup.
    • The guitar cannot be adjusted to meet the tolerances and needs fret work. 
  • The operator makes decisions about how to optimize the guitar and maximize playing experience.  This is THE most vital part.  A good operator will make good choices.  PLEK is only a tool though, so a bad operator could make poor choices and the outcome would be less than ideal.
  • PLEK then cuts frets to proper level and the guitar is ready for cleaning and setup.
  • After frets are buffed and dressed then the guitar goes through the entire setup process and back in PLEK for a final scan.  This provides a record of every step from beginning to end for later review if needed.

My luthier can do a better job than PLEK.

As a luthier myself, I can confidently tell you that is 100% false.  Even using a jig to simulate string tension and and having the finest motor skills of any human ever, they still can only be within tolerance.  Which is fine.  There is no reason to work on a guitar to make the fret level perfect, only to make it within tolerances that will not negatively affect the instrument. But...can they do it every time?  Can they compensate for variables that are not visible to the naked eye?  Where a luthier is really key is the art part of the equation.  Things like dressing the frets are something PLEK will not do.  All art still has to be done by a human and all decisions have to be made by one.  With this in mind, PLEK is just the ultimate tool for the jobs that it does.  Nothing more.  Nothing less.

Why does a new guitar need PLEK (especially a higher end one - shouldn't it be perfect)?

As you can see from the example above, we do everything we can to get the guitar right without actually doing a level and crown.  In those cases we have a scan and setup with no actual mill work.  But why would a guitar not be right from factory?  The answer lies mainly in one key component:  The initial leveling of the frets takes place with no strings on it.  This means that once you apply 190 or so pounds of tension on the neck with strings, things can (and often do) change.  Things that we see often are twist in the neck, humps near the body joint, and generally uneven frets.  With PLEK doing all of its measurements under full tension, it can actually compensate for these issues making the guitar as close to perfect as possible with strings on it.  Wood is wood and regardless of the price of the guitar, it can sometimes just move in unexpected ways under tension.  Regardless of the price of the instrument, PLEK will simply ensure that you have a perfect platform to allow for ideal setup.

Will my guitar be completely buzz-free after PLEK?

No.  It will not.  Guitars have frets and metal strings (in most cases).  There will always be some buzz associated with these unless using very heavy strings with higher action.  PLEK will only make sure that the frets are in the most ideal condition to minimize buzzing, increase intonation, make bends not fret out as much, and generally play its best.  As a flawed instrument, a fretted guitar will never truly be buzz free or have perfect intonation.

Where are the LASERS?

There are none.  This is a common question, but PLEK is purely mechanical in nature and does not employ the use of any optical devices.  Although, it would be pretty cool it it did have lasers...

So in conclusion, PLEK is just a fantastic tool for a competent operator to optimize a guitar's fretwork and several other jobs that require precise visibility and tight tolerances of milling.  

August 11, 2022 — Ben Calhoun