Any Love for the Plek Machine?

[lammie200]

...Ok, the Plek may be better than any careless and unqualified fretting done by hand in some major guitar plants.

Are parts makers like Warmoth, USACG, Musikraft, Allparts, etc. major guitar plants? Doesn't matter to me - their necks will still likely play better after Plek'ing. Also, from the Plek website:
Features

Plek Station features include:

• Fret dressing and crowning in accordance with luthier instructions
• Nut slotting/shaping at precise angles and depths to achieve optimal string action
• Fret slot cutting
• Nut pocket cutting
• Saddle/Saddle slot cutting
  
• Fingerboard engraving
• "Virtual Fret Dress" technology enables work effects to be previewed before implementation

In addition to all of this, the software embedded in the Plek Station can:

• Scan instruments to analyze fingerboard and fret-plane relief under each string
• Identify and view problem areas
• Preview the effects of intended work using "Virtual Fret Dress" technology
• Compare current neck and fret-plane relief with an optimum relief curve calculated from current and target instrument specs
• Indicate how much fret material needs to be removed to eliminate the risk of buzzing and maximize playability for the given specs
• Plane optimum relief and fall-off into a fingerboard
• Interpolate fret dress requirements to achieve a smooth compound radius transition along the neck
• Calculate and combine optimal fret-plane relief contours below individual strings
• AND much more besides

One thing that the Plek Station can't do however is to replace the skill, experience and craftsmanship of the luthier behind the machine. We see the Plek Station as a tool to enable you to take your guitar building skills to the next level.

[LtKojak]

Funny thing about MRI and my brother in law is physician.

Ok.

We never treat MRIs we treat patients.

Who is "we"? Are you a physician as well? I'm confused.

About 40% of lower lumbar MRIs in men over 50 will randomly show herniated disk, but no symptoms and person had no real complaints.

This is something that makes me laugh. How can you know a percentage of MRIs are showing something that's not really there, specifically cases with NO SYMPTOMS? If they didn't have any symptoms, why did they get a MRI in the first place? Just because? In my neck of woods, you only get a MRI if it's ordered by the doctor, and in cases that the symptoms suggest something of a certain gravity, like tumors.

Not to argue at all I just found that interesting.

On the contrary, I think you just made the whole thing up as a way to justify your need of "confirmation bias" to the statement I called you on before.

I still think Plek is overpriced for almost all repairmen in business and the cost to have it done not worth it.

Of course you do.

What a clumsy way of pitching your own services as a repairman. Specially when you start by telling you send your own instruments to a pro luthier that's not you, and finishes telling that you can do just as well for cheaper?

Your Honor, I rest my case.

Thanks for the laugh, though.

[Guitarbean25]

I am going to cause controversy but here goes. I think the plek is way over-rated and expensive. I believe I can do as good of job as the plek machine and I am cheaper from the rates I see. I am not sure of the cost but I see prices over $200 to get your frets dressed. This is too much when I can look at your playing. I see how you play and then I can make certain adjustments on how I set your guitar up. The plek does not take into account that you might have an really light touch or heavy handed.

Players who have a light touch and are not aggressive can get away with much lower action in some cases. If you hit the strings hard enough the frets will rattle unless you are set up like Freddy Green. The process of a fret dressing has many things to consider but if you need a complete set up and fret dressing only and strings, for $125 I will get it probably to your liking. Now there are limits because everything is a trade off and compromise to some degree. If you want a powerful sound, with absolutely no fret rattling, then you cannot have super-super low action. If fact you really cannot even have low action if truth be know if that be known.

The quality and condition of frets and fingerboard have much to do with how the job can come out. Sometimes it is a choice between dressing out the frets one last time and trying to make a go of it or fretting the guitar. New frets and a fingerboard that is in good shape with proper radius will make the job easier. I generally error on the side of caution and recommend dressing them out unless they are fretless wonders. It is also much less money and time to do a fret dressing.

Things have to be all correct at the nut. Proper spacing, proper height ( nut) , neck with correct amount of relief. From this point it is all in the frets being level and consistent. Most modern guitars made well should require very little relief. If things are correct I prefer the neck have very little relief and then you the play can set the action at the bridge. Your needs change from time to time and this allows the best I think. Some players need more relief if they are heavy handed so again must take that into consideration.

My take is the plek..................not able to think and it is expensive to have done let alone buy the machine.

I wish you lived in San Francisco :-/

A shop here alway recommends a $200 plek when walk in the door...even if you're just buying strings!

[Flyin' Brian]

I'm absolutely in favour of the PLEK process.

I have had 3 guitars done by superb luthiers and they are all outstanding, much more playable and in one case superior to the guitar the day I picked it up at the factory 11 years ago.

If I had a shop, I'd invest in one just for the time saved and efficiency. At the shop I currently use, he had a Gibson double neck in for fret dress...something that won't fit in the PLEK machine.

In the time it took to complete that job, he completed 7 PLEK setups, which by the way does include some handwork such as dressing the fret ends. He's had his machine for a year and it already paid for itself.

Also the PLEK job is continuously repeatable, since a complete file is stored in the software.

Many luthiers say that they can do the job as well. OK maybe so in many cases, but not as efficiently and repeatedly.

"German junk technology" indeed

A closed mind is like a parachute.....etc.

[LtKojak]

If the Plek folks are claiming that the frets tops over all the neck are within .003 millimeters that's simply not accurate. This is one ten thousanth of an inch were talking about. I'd say they'd be lucky to get .001" . A new, massive surface grinder with a rigid setup would be hard pressed to get an 18 inch long flat surface flat within .0001". Add the wood, the complete lack of rigidity of the setup, the 3- D lofted surface and the fact that everything changes with tension, weather changes, etc. and were talking about way less precision than that even.

I love the time saving aspect of the PLEK and it's very interesting, but give me a break. The marketing and promotion are over the top.

Had you been in the same room with a Plek machine, I'm pretty sure your opinion would be different.

Several people in this thread are passing judgement on something they haven't even seen at work, let alone experiencing playing his own instrument before and after the Plek treatment.

What is it that gets some people the need of talking about things they know nothing about?

I can't help but to shake my head in disbelief...

[Jazzstdnt]

I've had a few guitars PLEK'd for $150.00, in approximately three hours each time. Repeat visits were cheaper, even free once. Results were the best I could dream of, even when the process only involved a truss rod adjustment that was calibrated very finely. That guitar plays better than anything I have owned before or since. I agree that the machine operator is key.

[vejesse]

What is it that gets some people the need of talking about things they know nothing about?

I can't help but to shake my head in disbelief...

Really. Have you worked as a machinist? Run Surface grinders, CNC mills? Are you familiar with the sort of accuracy that these machine tools are capable of? And how many refrets do you have under your belt?

Machine tools require rigidity to maintain accuracy and large seasoned iron castings paired with massive ultra precise bearings and hand scraped ways provide that. I look at the Plek machines and I see aluminum housings everywhere. That means big flexibility combined with big dimensional changes with changes in temperature. I see that the neck is not fastened down in any way that would provide real stability. And I see they use a plain formed toothed milling cutter, and that means a minimum depth of cut, as well as a cutter that quickly loses it ability to maintain it's form and remain sharp.

The CMM scanner outfitted within the PLEK may be plenty precise enough to scan the fret tops, but the overall design of the machine isn't capable of conventional machine tool precision. Not even close. And a guitar is too squishy and subject to dimensional changes to maintain that same accuracy.

I looked at the Plek website again today and nowhere did I see that they're still advertising 0.003 mm accuracy as they used to. I'm not sure what they actually meant by that. But if they not making that claim currently that's a wise move on their part because there's no way in hell that machine will leave the fret tops within .0001" of a flat plane in the lie of the string, or within .0001" of the 3D lofted projected dimensions of one of their neck relief programs.

If you want to argue that despite it's limitations the machine is capable of enough accuracy to work well on guitars I can buy that. What I can't buy is that the machine can easily reproduce a Plek CAD neck drawing with exceptional precision. A cnc machining center will, but the folks who design and build those machines don't make claims of accuracy they can't deliver.

Despite this I'm not really knocking the machine, I think it's neat and a huge time saver. For a shop that can afford a $100,000 Plek Station I'm sure it's great. I'd love to have one myself to mess around with. You know fret work is very challenging work and not many people seem to be good at it. If a machine can do it and do it very quickly, that's great. But I've played guitars that had the process done and they don't necessarily play any better. In fact, some of the Gibson and Heritage guitars I've played the last few years that were purportedly subject to the Plek had lousy fretwork. Why is that, because the operator wasn't competent? I thought the biggest advantage of the Plek was that unskilled factory folks could do a good, fast job leveling frets. Now the limitations of the machine and the materials may be apparent.

[lammie200]

...One thing that the Plek Station can't do however is to replace the skill, experience and craftsmanship of the luthier behind the machine. We see the Plek Station as a tool to enable you to take your guitar building skills to the next level.

...that were purportedly subject to the Plek had lousy fretwork. Why is that, because the operator wasn't competent? I thought the biggest advantage of the Plek was that unskilled factory folks could do a good, fast job leveling frets. Now the limitations of the machine and the materials may be apparent.

Not sure what you are getting at. I quoted the above from the Plek corporate site.

[LtKojak]

Have you worked as a machinist?

I've been trained as a machinist in school.

And how many refrets do you have under your belt?

I don't see how is this relevant, but my records show about a hundred, and about twelve times that amount in fretwork, meaning leveling, crowning and polishing of frets, thank you very much for asking!

I look at the Plek machines and I see aluminum housings everywhere.

Not everywhere...

I see that the neck is not fastened down in any way that would provide real stability.

You can add up to three points of support for the neck. But of course, you won't know that because you haven't seen one Plek machine actually working... and ask me how do I know...?

I see a cutter that quickly loses it ability to maintain it's form and remain sharp.

You know, all cutting tools have a life, isn't it? When they're not effective at its job, you change it. It's called "maintenance", and there are guidelines to that in the written manual.

The CMM scanner outfitted within the PLEK may be plenty precise enough to scan the fret tops, but the overall design of the machine isn't capable of conventional machine tool precision. Not even close. And a guitar is too squishy and subject to dimensional changes to maintain that same accuracy.

That's your opinion, just from looking a picture of the machine. I beg to differ, having my info from actually using the machine. Plus, the machine has a self-running program that would check all points and processes to see it keeps the requested accuracy.

What I can't buy is that the machine can easily reproduce a Plek CAD neck drawing with exceptional precision.

Again, what actual knowledge do you posess to support the statement? From the descriptions given, it's pretty obvious you've never even been in the same room with a Plek machine, am I right?

But I've played guitars that had the process done and they don't necessarily play any better. In fact, some of the Gibson and Heritage guitars I've played the last few years that were purportedly subject to the Plek had lousy fretwork.

Unfortunately, there's no way to verify the veracity of the statement, meaning that maybe the allegedly Plek'ed guitars actually weren't, as I'm pretty sure you haven't personally witnessed any of those. But as I'm on a generous mood, I'm going to give you the benefit of the doubt, which will lead us to the next paragraph:

Why is that, because the operator wasn't competent? I thought the biggest advantage of the Plek was that unskilled factory folks could do a good, fast job leveling frets. Now the limitations of the machine and the materials may be apparent.

Once you get the machine, there's a time you need to get to know it, what it does and what it doesn't, and what it take the longest is to interpret the readings you get from it. If you don't have any experience as a luthier, chances are, you're going to botch some jobs. Or, not really botching, just not the desired outcome. And, FYI, the machine don't do setups. The operator, or luthier does.

Since he got the machine in 2010, my pal has had several thousand jobs on record, for his own guitars and many others, manufactured both in Italy and abroad. Plus he and his crew take a trip to the factory in Berlin to keep up-to-date every year.

Bottom line: you assumed too much, know very little, but decided to talk about anyway.

Don't complain now, mate. You asked...

[ptchristopher3]

The expression "what a tool" comes so readily to mind.

[ptchristopher3]

Hi vejesse,

Hope you are doing well, been a while.

I understand your comments regarding the practicality of precision in luthiery.

In my view the Plek system offers one very specific value that is hard to replicate (yet I am sure you and I have had to a few times).

The plek measures the fret positions under the combined load of the strings and truss rod. From this measurement it answers to its masters wish (for better or worse) by cutting each fret with no regard for the frets position relative the adjacent frets AFTER the loads on the neck have been removed.

You and I observe the situation of a fret job (or fret rescues of many sorts) under load, but our manual fixes are partly dependent on the relative position of the frets to adjacent frets with the loads removed.

So if we observe a compound ("s") bow in the neck, or a relief difference on the bass side vs. treble, or other artifact that can disappear (or change significantly) when the load is removed, we need to compensate as we work by hand.

It works, and surprisingly well considering what ham-fisted hacks we are.

But the Plek is better at measuring under one set of conditions (string and truss rod loads) and working under a different set of conditions (loads removed).

It seems not even slightly surprising that to one player and guitar the Plek could be a miracle, while to another it could be ok-ish at best.

So it seems to me that the plek offers two specific advantages:

- It can automate a manufacturing process to reduce the need for skilled labor.
- It can under a very specific set of circumstances potentially be more precise IN PRACTICE vs. a skilled luthier.

Now this specific set of conditions is not a practical problem very often at all, but it does happen in my view.

Chris

[deacon Mark]

I generally work on all kinds of guitars but I specialize in archtops. Folks tend to bring me those guitars since my background with Hollenbeck and Barker. I have not seen one in action on a carve top like a Super 400. I would like to know if acoustic guitars are harder to get set into the machine? They take up much more space and the machines I have seen are not really large. I am asking because setting up fret jobs for solid bodies and archtops is very different in the shop. The way I do them in my little shop requires two different jigs to hold the guitar. Strange as it is I always feel more comfortable working a super 400 rather than a Les Paul. I suppose the plek does not care what guitar is in machine, the human side of us has bias.

Recently I did a fret dressing on 1948 Super 400 and no matter what I find myself being much more attentive to the task. The very cheap flat top I did a week before just did not quite get my attention as far as worry. These are things your repairmen might not really want to tell you. I tell you I would want to see someone venture their D'angelico to a plek before I would allow mine to take the test.

[Flyin' Brian]

What is it that gets some people the need of talking about things they know nothing about?

The anonymity of the internet.

[vejesse]

Fine "Kojak", you win the internet again, as you no doubt always do. And my apologies - I didn't mean to dismiss your experience .

By the way, here's an anecdote regarding fine Italian craftsmanship I'm sure you'll enjoy.

I bought a new Minimax jointer/planer last year and the outfeed table had a dip of 0.007". The green casting had obviously warped after it was ground and the machine was basically incapable of flattening the face of a board. I called the tech support and they emailed the SCM office in Italy. Guess what their tolerance for flatness was that day: 0.007". Something tells me it would have been 0.015" if my table had a dip of that amount.

[Flyin' Brian]

Recently I did a fret dressing on 1948 Super 400 and no matter what I find myself being much more attentive to the task. The very cheap flat top I did a week before just did not quite get my attention as far as worry. These are things your repairmen might not really want to tell you. I tell you I would want to see someone venture their D'angelico to a plek before I would allow mine to take the test.

You gave yourself away here.

Remind me not to trust my guitar to your situational ethics regarding getting the job done right based on your judgement of a guitar's value to you rather than to that of its owner. A true professional will take as much care to ALL of his jobs because that's what he's been entrusted (and paid) to do.

If I had a D'Angelico that needed fretwork I would definitely bring it to MY chosen luthier to use his PLEK or whatever tool that he felt necessary to use to get the job done. Because PLEK or not, I KNOW that he's going to concentrate, show concern and do his absolute best work on EVERY guitar he touches.

[ptchristopher3]

The anonymity of the internet.

This implies that vejesse is truly anonymous and that he knows nothing about stringed instruments.

Both are decidedly false.

******************************

One contributor on this thread once claimed particular knowledge because he had relatives who lived near Stew-Mac.

Another contributor on this thread claimed that as strings stretch with use, and harden/stiffen with use, the tension of the string at a given pitch goes up. He claimed expertise in this because he had met famous people.

In both cases the tension actual goes down. Even for those who have met famous people.

*****************************

The principles regarding the use of tools to work on guitars strike me as very interesting.

Chris

[Jazzstdnt]

I generally work on all kinds of guitars but I specialize in archtops. Folks tend to bring me those guitars since my background with Hollenbeck and Barker. I have not seen one in action on a carve top like a Super 400. I would like to know if acoustic guitars are harder to get set into the machine? They take up much more space and the machines I have seen are not really large. I am asking because setting up fret jobs for solid bodies and archtops is very different in the shop. The way I do them in my little shop requires two different jigs to hold the guitar. Strange as it is I always feel more comfortable working a super 400 rather than a Les Paul. I suppose the plek does not care what guitar is in machine, the human side of us has bias.

Recently I did a fret dressing on 1948 Super 400 and no matter what I find myself being much more attentive to the task. The very cheap flat top I did a week before just did not quite get my attention as far as worry. These are things your repairmen might not really want to tell you. I tell you I would want to see someone venture their D'angelico to a plek before I would allow mine to take the test.

That's understandable. A vintage D'Angelico is something you can't replace at any cost. You can get another Super 400 though.

Regardless, my PLEK jobs were on carved top Gibsons and all went swimmingly. I'll admit I was a little bit worried but then I always am. I never leave my guitars with a tech overnight, and in fact usually wait and watch the work happening in real time. Watching the PLEK in action is actually pretty cool.

[LtKojak]

One contributor on this thread once claimed particular knowledge because he had relatives who lived near Stew-Mac.

That would be me, and yes, I still have family living in Athens, Ohio.

The "particular knowledge" was a guesstimate, derived from a simple price list you didn't want to acknowledge the existence.

Any particular detail I can help you with?

[LtKojak]

I bought a new Minimax jointer/planer last year and the outfeed table had a dip of 0.007". The green casting had obviously warped after it was ground and the machine was basically incapable of flattening the face of a board. I called the tech support and they emailed the SCM office in Italy. Guess what their tolerance for flatness was that day: 0.007". Something tells me it would have been 0.015" if my table had a dip of that amount.

Oh, poor you... you should've bought a German one!

[deacon Mark]

I did not give myself away I am a public person with all flaws of the human condition. I struggle each day to accomplish what God ask me to do. In that I am looking at foggy windows. You are correct never allow someone like myself to work on a guitar you have, I am flawed.

[Flyin' Brian]

I did not give myself away I am a public person with all flaws of the human condition. I struggle each day to accomplish what God ask me to do. In that I am looking at foggy windows. You are correct never allow someone like myself to work on a guitar you have, I am flawed.

I'm retired now as a corporate pilot, but I could only imagine what people would think if I said that I didn't plan, execute and complete a flight safely because I had the company new hires on the airplane instead of the CEO.

[vejesse]

Hello Chris,

So it seems to me that the plek offers two specific advantages:

- It can automate a manufacturing process to reduce the need for skilled labor.
- It can under a very specific set of circumstances potentially be more precise IN PRACTICE vs. a skilled luthier.


Chris

This is my general understanding as well. As with any CNC tool it's a labor saver and it's also likely capable of much more accuracy than a human is capable of, at least at speed. Regarding the Plek's remedy for problem necks and necks without truss rods, etc. of course the analog approach is a neck tension simulation fixture, i.e. the "neck jig". I agree that a twist that only appears under tension is almost impossible to deal with. But a neck jig does help a lot and they don't cost 100 grand to make.

I may be obtuse, but my understanding of ideal guitar fret geometry is very simple and I believe universal regardless of approach: level the frets so that under string tension you have relief from the nut up to the ninth fret or so, then completely flat to the end of the board. (violin family instruments and the nylon string guitar don't necessarily follow this scheme) If there's a hump at the heel (as there usually is given time unless it''s leveled into the wood) those fret tops have to be taken down below the rest of the frets because string tension pulls the cantilevered neck upwards. This corresponds to the Dan Erlewine school of thought, and I 'm confident it's gospel regardless of how the job is done. In a neck that behaves more or less "normally" string tension tends to to pull the neck into the type of relief slope that seems to work well enough. If you do an excellent job of leveling the frets and make sure there's virtually no "rising tongue" under tension, the guitar will invariably play very well, even with low string height and almost no relief.

So with the above in mind here's a question for the people promoting Plek: If you only want relief from the nut to the ninth fret, how many endless variations of relief slope are actually useful? Are all these programs simply there to deal with how the neck behaves under various amounts of tension? I do understand the Plek toolpaths actually cut the relief into the fret tops as you might with a classical guitar, rather than simply allowing the string tension to do it.

Here's another question or observation: I can only assume that the reason a highly skilled operator is required to run this thing is because of the flexible nature of the machine's construction, how it holds the neck in only three spots, the flexible nature of a guitar, etc. This whole system is basically a noodle compared to "conventional" CNC machine tools, yet it's expected to deliver more accuracy. What happens if you remove the guitar from the fixture and then clamp it back in? Can you reproduce the same exact placement and pressure? I don't believe that's possible, especially if we're trying to hold things to say, 0.001" of an inch. So you scan it again, cut it again, scan it again...now this is starting to feel like frustration.

Here's another: The form tooth milling cutter has a minimum depth of cut. Unlike a grinding wheel which can take off .0001" per pass (or less if you "spark out"), a milling cutter exerts much higher cutting pressure, and takes a certain minimum amount of material away, usually .001" or so. Is this why necks that get "pleked" sometimes get ruined by inexperienced hands who keep at it until the frets are too low? Low frets really suck. I believe they used to use a CBN wheel which seems much better suited to this sort of thing. But they can cost a lot.

I don't want to be a putz but just for fun here's my challenge: Ask the Plek engineers for a tolerance that all the fret tops should be within after a final cutting pass, that based on their promotional materials. Then have the guitar "plekked". Then take it to an inspection lab. Clamp the guitar down to a big Starrett granite plate and use a large, expensive CMM to inspect the fret tops. I'm betting that the guitar might play "just fine", but that the fret top tangent points will not correspond very closely to the CAD drawing used to generate the toolpath. And the tolerance will not be anywhere close to within 0.0004" as they may have advertised.

If it does, I'll eat my words.

[lammie200]

...And the tolerance will not be anywhere close to within 0.0001" as they have advertised.

If it does, I'll eat my words.

I am not seeing where they advertised that tolerance. Where is it?

Also, frets are sized to the 0.01". What good would precision to 0.0001" do?

[vejesse]

Looking again I found this on their web site:

While we are talking of figures, let's take a look at the accuracy of the Plek system.
The scan has an accuracy of plus or minus five thousandths of a millimeter or plus or minus 2 10-thousandths of an inch.
The fret cutter has an accuracy of plus or minus one hundreth of a millimeter, or four ten thousandths of an inch.
The high-frequency spindle used in nut and saddle cutting has an accuracy of plus or minus five hundredths of a millimeter, or two thousandths of an inch.

[ptchristopher3]

Veej,

100% agreed that the actual fret top tolerances in a ready-to-play plek'ed guitar will not follow the claimed sub-system tolerance at all.

And that this does not mean the guitar will play poorly.

It also does not mean that the Plek system is useless.

To me it does mean that absurd isolated tolerance claims are not very helpful.

Chris