Guitar builder needs assistance

I’m currently building my 5th guitar, this time I have access to a GF. I’ve used it to create all my templates, so far it’s been a huge help and major time saver. My issue: I used the GF to score lines for the frets on the fret board. Worked great! Im having trouble lining the fret markers for inlay later on each odd fret space. I created a shape and spaced them out exactly to where they should go using the same file template. I placed my test board in the machine (which has the fret lines engraved) and placed it perfectly horizontal. I then took the small images and placed them exactly where they should go on the image taken from the GF app as I would normally for any project. Every time I go to print, it engraved either 1/4 inch left or right of the lines. And not always 1/4 inch it’s all over the place within a 1/4 inch. It just won’t seat the image exactly where it needs to go. I cannot risk ruining my final piece of wood until I nail the position? What’s the issue? Why won’t it put the image exactly where it needs to go? Any tips , tricks, adjustments, I can do to remedy this?

Steps already taken:
Camera is clean
Material thickness is measured with calipers
Offsetting the difference does nothing since it never lays in the same place twice.

What more can be done?

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I’m not 100% sure I’m understanding what you’re describing but, if I am I have 2 suggestions

1st would be to put all the fret engrave lines into a single .svg file grouped together - as long as your art board is 12x20 they will show up on the :glowforge:UI spaced exactly correctly and then you only need to line up the first one and the rest will be correct.

2nd would be to note that you’d need to Set Focus on each spot before you placed the individual engrave lines - otherwise you’re trying to eyeball things on a fisheye camera.

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Ok I know exactly what the issue is. The wood is too dark and the laser is getting confused. I had the exact same thing happen a few times(when trying to engrave a black Glock gun slide) and in this specific case it’s when the alignment laser is unable to get it’s bearing it’ll throw weird issues like this. Bast thing I can recommend would be to painters tape or masking tape off the section you want to engrave, as long as it’s any other color then black and you should finally get the results you were looking for. As a caveat you may need to kick ether the power up by 5 or decrease the speed by 5-10 depending on the type of wood to accommodate for the additional layer to burn though. It’ll take some trial and error I’m sure but I’m 100% certain this is what is causing your issue.

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Thank you for the reply! This is very helpful, however the test runs I’m doing are not on the black fretboard you see in picture. I’m running it on 1/8’ ply which is yellowish as you know. The shape and lines are exactly as you see in the black final version in the picture. I will try tape anyway and perhaps darkening the lines on the tape, why not! thank you!!!

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Have you tried using @MyDogsThinkImCrazy jig set up? Not positive it speaks to your issue, but it will align things accurately!

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When was the last time you took the print head off and gave all the lenses a proper wipe down? I just had to do it recently and it was much dirtier then I thought for.

AHHH I never considered the fisheye lens. It is possible to set an area of focus?
This is excellent advice, I will try it and let you know. Thanks so much!!!

No I have not, but I will check it out. Thank you.

Every day, I’m a clean tool nut. Thank you!!

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That might actually be too much cleaning, check the sensors on the bottom for scratches etc

I build banjos, not guitars but the process is likely similar. Though banjos do not have to worry about radiused fretboards. I also use the GF to accurately score my fret positions. Think I follow everything you are doing up until…

Are you trying to engrave pockets for inlays? If so, maybe that is most accurately done at the same time you score the fret positions. I’m a little confused when you said you were using the yellow birch. Sounds like you are doing something with a template. I use a GF created template for my fretboard position markers but the order of your steps may be different than mine. If you explain it further I may have recommendations.

I intentionally do not add fancy inlays to my banjos fretboards, only position markers. But that’s only because I dislike bling on a musical instrument. The type of guy that would run a key scratch down the side of my new pickup just to get it over with. It’s supposed to look used.

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I realized yesterday, I should have done the inlay pockets same time as fret slots. No matter what I try I cannot get the pockets to line up with the lines. It’s not super fancy inlay but it does butt up against the frets. I did however come up a solution. I’m putting a cutout of the shape over each fret to be inlayed to act as a stencil/mask. Then just running full squares over it so it only engraved in the open shape. Worked well in a text run. I am using 16” radiused Macassar Ebony.

Live and learn I suppose. This does however expose an important flaw in this machine. The camera is incapable of capturing image good enough to engrave images precisely.

Using the set focus tool many of us are able to line things up quite precisely with only the camera. The Glowforge specs state that the camera is accurate within 1/4", but most users get far better results than that. We also utilize the placement tool and jigs for absolute precision.

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Yes - that’s exactly what Set Focus does. The default is directly under the camera - clicking the 3 dot menu, and Set Focus will bring up a focus box, and that will make it focus wherever you put that box. I use it on every single job - even when using PG materials - get in the habit :slight_smile:

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Have you run the lid camera calibration routine? It worked almost perfectly on my unit. I see almost zero difference between the lid image and the laser cuts/engraves once I ran the calibrator once and of course careful use of the Set Focus command before running a job. Used to be off by about 1/8" before running the re-calibrator.

In my opinion running the camera calibration routine should be done as one of the first things after receiving the GF or after moving it to a different surface. UPS shipping bounces everything around and moving the GF from one table to another could flex the case if not perfectly flat. Flex the case and the lid camera image with it’s S/W adjusted fisheye lens might be significantly off.

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Nope no scratches, thanks for heads up.

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This will be done ASAP. Thank you!

The half engraved is how off it was from what I thought was perfect placement. The finished one is using my stencil mask method. It takes a bit longer to set it all up, but I’m using a $50 piece of ebony, not 1.50 piece of ply, I’m taking no chances.

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Wondering whether you will have problems with chipping the fretboard when hand sawing the frets with the inlay pockets so close. Maybe not, but I always think about things that might go wrong.

It will almost certainly be an issue if it ever needs to be refretted.

Nah, not my first rodeo with this type of inlay, just doing it using modern technology is the learning curve. I’ll be using stainless steel frets, not changing them anytime soon. Thanks for looking out though, I appreciate it!

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