CNC PLEK Combo Idea

Adinol

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Greetings,

I'm not sure if this has already been discussed but it occurred to me that it would be relatively easy to build a CNC PLEK Combo machine. After all, a PLEK is just a specialized CNC.

Many builders put together their own CNC's .

Has anyone even built a CNC PLEK Combo?

Thanks...
 

pshupe

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I think the big thing about the PLEK is the ability to scan / probe the existing guitar and know exactly where it is in relation to what needs to be done. If you are pumping out a couple hundred guitars a day and do not have a 100 people with the experience to do the fine tuning required it is probably worth whatever a PLEK machine costs. I doubt the hobbyist will be able to duplicate that on an inventables machine. LOL

Cheers Peter.
 

Adinol

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I think the big thing about the PLEK is the ability to scan / probe the existing guitar and know exactly where it is in relation to what needs to be done. If you are pumping out a couple hundred guitars a day and do not have a 100 people with the experience to do the fine tuning required it is probably worth whatever a PLEK machine costs. I doubt the hobbyist will be able to duplicate that on an inventables machine. LOL

Cheers Peter.
I'm thinking of the boutique builder that is setting up a CNC shop and does not have high volume output.

I have no experience with CNC machines but it is my understanding that any CNC can be made to scan any existing shape. If this is correct I think it would be doable to construct a jig that simulates string tension on the neck, strap the guitar, have the CNC scan the frets and then do a pass at PLEKing the frets.

It is my understanding that a PLEK is just a specialized, vertical CNC machine that does this one thing. But I don't think it has to be vertical and I think a CNC can do the same job, as long as you build some kind of neck tension simulation jig (not that hard to do) and work on the CNC code a bit (which I know nothing about).

I think even an existing CNC setup can simply be expanded into a horizontal PLEK setup.

Personally, I don't gravitate towards the CNC and PLEK direction and I am not thinking of building anything of this sort for myself. I am simply putting the idea out there for those who do CNC work.

Hope this makes sense.
 

pshupe

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There are two different technologies here. One is the CNC and it would be very simple just to program what should be done to the frets, nut and bridge to get the exact setup one requires. The machine itself may cost about $10K for the precision needed, could be much less.

The other part is scanning the existing guitar and using that as a base to setup the previous requirement. I do not know what technology PLEK uses but a scanner for the precision required would probably be in the high 5 figures and possibly into the $150K range. Then you would have to have programming to take that information and adjust to tell the CNC machine what to do. I think those PLEK machines are around $250K. You would have to have quite the business plan to make that purchase feasible.

It would be cool for someone to try it but I doubt it would be realistic. If it were PLEK wouldn't be selling those machines for $250K.

Cheers Peter.
 

mistermikev

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I've read... that a plek machine isn't perfect (no, did he just say that). I'm told that the results in most cases are no better than a competent luthier could do. In some instances... not even as good... because one can ultimately string up the guitar and make fine-tune adjustments that a plek machine (however close to simulating tension on a neck may be) just isn't capable of.

as I understand... there is software for pcb creation via cnc that will map out the actual height of the pcb board and adjust the z axis accordingly... to hold a consistent cut on an inconsistent surface. I imagine that you could probably take a cnc as it is and using that software (assuming the right tool) you could crown a fretboard. it would be pretty easy to use a cnc as it is to do a level... as long as your cnc was accurate. that said... the time that it would take to get a neck mounted in a way that one could do those operations... and the time it would take for the cnc to run through those operations... probably wouldn't be worth it. Not to mention... one would need some specialty bits to actually polish and finish the frets. starting to sound like it would be easier/faster and possibly more accurate to just do a level and crown.
 

cmjohnson

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I can see it now...I design, engineer, and build a guitar where the entire string path is machined out of a block of 4340 steel and the mirror polished, precision ground tungsten carbide frets are individually replaceable IF they ever show signs of wear. Just order up a new replacement fret for the one to be replaced (the number of the fret matters!) and unscrew the old one, screw the new ones in, and the action is guaranteed perfect.

The catch is twofold: COST and WEIGHT. It's a 30 pound guitar and the frets are 250 dollars EACH.
 

Adinol

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There are two different technologies here. ...

...I do not know what technology PLEK uses but a scanner for the precision required would probably be in the high 5 figures and possibly into the $150K range.
Ouch. I didn't realize that.

It would be cool for someone to try it but I doubt it would be realistic. If it were PLEK wouldn't be selling those machines for $250K.
You make a good point. I guess technology has a tendency to get cheaper. I'm sure the price tag is high because there is no competition, yet. I can't even imagine how it pays for some of the businesses I see on YouTube to own a PLEK machine. You gotta PLEK a lot of guitars to pay off for that machine, before you start making profit. By then there may be some cheaper alternatives.

I've read... that a plek machine isn't perfect (no, did he just say that). I'm told that the results in most cases are no better than a competent luthier could do. In some instances... not even as good...
I can actually confirm that, from my own experience. I've checked many Gibson guitars and found high frets. OR frets like that...

plek.jpeg


...the time that it would take to get a neck mounted in a way that one could do those operations... and the time it would take for the cnc to run through those operations... probably wouldn't be worth it.
I'm not sure, because the way I imagine this might work (and I might be wrong) should be pretty simple. Basically, the way I saw they do it in an actual PLEK machine, except that it would be horizontal.

Not to mention... one would need some specialty bits to actually polish and finish the frets.
One thing I've noticed about Gibson guitars, now, is that their PLEK'd frets need polishing. I think they just don't polish to save time, and costs. But I did see a high end Gibson that did have polished frets and I wonder if the did the polishing manually, after PLEKing.


...starting to sound like it would be easier/faster and possibly more accurate to just do a level and crown.
I do a level and crown job pretty fast, these days. In fact, I am not even in favor of PLEKing and I do believe good manual L&C is superior and more reliable. This post was just about sharing an idea for those who might be more CNC oriented (which I am not). But clearly I don't know enough about CNC to know how easy (or not) it is to build a hybrid CNC/PLEK machine.

Thank you all for your thoughts and information.
 

mistermikev

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Ouch. I didn't realize that.



You make a good point. I guess technology has a tendency to get cheaper. I'm sure the price tag is high because there is no competition, yet. I can't even imagine how it pays for some of the businesses I see on YouTube to own a PLEK machine. You gotta PLEK a lot of guitars to pay off for that machine, before you start making profit. By then there may be some cheaper alternatives.


I can actually confirm that, from my own experience. I've checked many Gibson guitars and found high frets. OR frets like that...

View attachment 522785


I'm not sure, because the way I imagine this might work (and I might be wrong) should be pretty simple. Basically, the way I saw they do it in an actual PLEK machine, except that it would be horizontal.


One thing I've noticed about Gibson guitars, now, is that their PLEK'd frets need polishing. I think they just don't polish to save time, and costs. But I did see a high end Gibson that did have polished frets and I wonder if the did the polishing manually, after PLEKing.



I do a level and crown job pretty fast, these days. In fact, I am not even in favor of PLEKing and I do believe good manual L&C is superior and more reliable. This post was just about sharing an idea for those who might be more CNC oriented (which I am not). But clearly I don't know enough about CNC to know how easy (or not) it is to build a hybrid CNC/PLEK machine.

Thank you all for your thoughts and information.
I think anything/everything looks simple right up until you have to do it! hehe.

as much as I hate doing fret work... not sure it'd be worth it to me anyway.
 

dspelman

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I do a level and crown job pretty fast, these days. In fact, I am not even in favor of PLEKing and I do believe good manual L&C is superior and more reliable. This post was just about sharing an idea for those who might be more CNC oriented (which I am not). But clearly I don't know enough about CNC to know how easy (or not) it is to build a hybrid CNC/PLEK machine.
I have a feeling that a lot of contributors to this thread have little or no idea how a PLEK machine actually works, especially if you're taking your guitar to a shop that does serious PLEK work.
 

ihavenofish

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you guys are over thinking this... or under thinking it?

building a machine that does what a plek does is easy as cake. Like all cnc machines, it's going to come down to what efficiency you are looking for.

You need a few ingredients:

1st, a fixture that can hold the guitar neck in a position that simulates string tension - generally placing the guitars into the machine WITH strings, fixturing, then releasing the strings.

2nd, a way to measure the fretboard and frets as they are. To do this you use a 3D probe. This is a common piece of CNC equipment. The machine moves around, and records where the probe hits the work piece. You can map every 0.5mm across the whole board if you like. The downside is that this can be rather slow, taking several seconds per point, adding up to many minutes or even hours to do a whole neck. There are optical scanners, visible laser, structured light, lidar, but actually making that data useful in less time than the 3d probe takes is a university research project all on its own.

4th, your machine needs to cut the frets. the 'scanned' fretboard creates a series of offsets that transparently tell the machine where the fretboard is. If you wanted to say, engrave a picture on the curve of the board, you just program your flat image, and the offsets from the scan map it to the curve of the board. Same goes for the frets, you want to basically engrave the frets. you program a standard "cut" for frets, and the offsets allow it to adapt to the existing board.

Some of you may have picked up on the missing step. Well, as per the gnomes in south park, that's where the profit is.
There's some soft ware (or a human) in the middle that interprets the scan. In the engraving example, there's nothing much to do... follow the offsets. With a fretboard, the human/software needs to tell the cnc how the fret carving maps. What's the nut width, what's the fret size, height, scale, number of frets? all that good stuff. That's what separates a plek machine from a box of hardware that resembles a plek machine.

It's a real big pain in the ass in the end, whether you do step 3 by hand or develop software to do it, and unlikely to be worth trying for most people.

On the flip side, there's an alternative method. At least for new guitars. Taylor has a video showing how they cnc fretwork. It takes effectively the polar opposite approach. You don't try to measure each neck and adapt the program. Instead you just make sure every fretboard (and probably neck) is exactly the same.
 


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