How Accurate Do You Need To Be When Slotting Frets?

[SchlockHorror]

So....in Hiscock's book the distances for fret slotting are written out to three decimal places of a millimetre. Whilst I appreciate that this level of accuracy by hand is..well...nigh impossible, I was wondering how accurately does everyone who slots their own fretboards work to?

Do you work to the nearest millimetre, half millimetre or what?

Also, I can't seem to find a long steel rule that shows half millimetres for more than the first 10cm. Does anyone know where I can get one, if I need one, that is?

Thanks.

[westhemann]

Do you work to the nearest millimetre, half millimetre or what?

When I slotted boards,I was usually within a quarter of a mm...alot of eye crossing and double checking involved...

Now I just buy them preslotted.

But I really don't know how noticeable it would be to be off a hair...you vary more than that just by finger pressure and unintentional bending.

But when I was in a band back in the day,the other guitarist played a Gibson,and I played an Ibanez...and I always felt I was a hair out of tune from him...but if he picked up my extra Ibanez or I picked up his extra Gibson,we were magically better in tune.

So it does matter.

[WezV]

i would try to be as accurate as possible, the correct tools help

use something like this for the fret to fret spacing, and the long rules to double check the nut to fret spacing

check both measurements frequently. You can set the vernier to .01mm accuracy - if in doubt get a digital one

now at the end of the day the slots are not going to end up with 0.01mm accuracy, but you gotta aim for it

[Woodenspoke]

The issue with measuring frets is two fold. One you are human. Second most 6" calipers should really be 18" or longer. These are very expensive tools. I am not sure how accurate you really need to place a fret given its position is modified by crowning a fret after the fact. I think though you want to be accurate or as accurate as you can be.

When you measure from fret to fret one human error translates onto the next fret . Even drawing a line can move the center point of your fret which translates onto errors on the next fret, and so on. Really its a series of human errors compounded one on top of another, by the time you get to the end of the board it could be a mess. Ideally each fret should be measured from the top of the board or the zero fret never from fret to fret. A long digital caliper is the best tool for this job. With a long caliper if you mis mark one fret its only one bad fret.

That is why it found if you want to make more than a few guitars or want accuracy that is repeatable buy templates. If you want to use non standard scales buy a long digital caliper.

[B. Aaron]

On top of that, a fret being out by 0.5mm won't make much difference if it's the first fret, but it'll make a much larger difference if it's one of the high frets... and it's the higher frets that are the farthest from the nut, and probably the hardest to get an accurate measurement on simply because it's hard to get looong calipers.

If you neeeed an unusual fingerboard length, check out lmii.com before you cut your own because they slot and radius fingerboard blanks to quite a wide range of scale lengths that you won't find at StewMac or Warmoth.

[Crusader]

I measured the frets on two of my bought guitars and wrote the results down to 0.1mm

When I compared the measurements to the calculated dimensions I found I was within 0.1mm accuracy except for the 5th fret on one which was 0.5mm out

So I think that proves my measurements were good, and that the manufacturer was right on the money

So yes, accuracy is important...and I have found that I can't do it!!!

[ElRay]

Also, I can't seem to find a long steel rule that shows half millimetres for more than the first 10cm. Does anyone know where I can get one, if I need one, that is?

You also don't need any fractional marks past the first major division (that's why a lot of engineering/drafting scales actually have the only fractional marks before zero). If you need 7.5 mm, then measure from the 1/2 mm before the 10 mm mark to 17 mm mark. If offsetting by 10 will take you past the end of the scale, then you can measure from the 2 mm mark to one more than the total distance you need for the whole numbers, and then use the marks before the 2 for your fractional amounts.

If you're going to hand measure, try finding a drafting supply place and buy the longest scale they have.

Another alternative is to use FretFind 2D, print-out your scale, and use that as a template.

Ray

[Crusader]

Also, I can't seem to find a long steel rule that shows half millimetres for more than the first 10cm. Does anyone know where I can get one, if I need one, that is?Thanks

I actually find it easier to deal with when there are just millimetres. I wish they would make steel rules without those half millimetre marks, its just a bunch of lines which kind-of blurr into each other and my eyes start to hurt like after looking into one of those 3D images

If you need 7.5 mm, then measure from the 1/2 mm before the 10 mm mark to 17 mm mark...Ray

Top idea, thats a bit like how a slide-rule works

[chops1983]

Stewmac gives an accuracy of 0.5mm either side but you should always try to atleast setout to 0.1mm. Basically if the measurement is 63.345mm i would mark it to 63.3mm. I think by eye you should be able to get relatively close to that. Then depending on how your slotting atleast your setout should be on the money. Not sure how others mark out but i always scribe my frets with a craft knife(scapel whatever its called) to guide my fretsaw. So far intonation on my guitars has been spot on. Just take your time,double check your measurements and if your handsawing have a break every few frets so your arm isn't tired and your accuracy of cut stays good.

[Southpa]

I stopped screwing around a long time ago and started doing all my fretboards with ACAD. Its the easiest and most accurate method I've encountered. There are plenty of drawing programs out there that you could use to get the job done. Make it 1:1 scale, print out in 2 sections and tape them together. Then cut out and tape onto fb wood and etch w/ ruler and sharp OLFA or X-ACTO knife. And marking the slots is a lot easier before the board is tapered.

[Saxon Marsh]

I found that the program from this site - http://www.brothersoft.com/fret-calculator-download-44473.html - allows you to both calculate the fret positions and print them out so that you can just stick the printout to the fretboard and cut away to your heart's content - Keith

[solomon684]

I stopped screwing around a long time ago and started doing all my fretboards with ACAD. Its the easiest and most accurate method I've encountered. There are plenty of drawing programs out there that you could use to get the job done. Make it 1:1 scale, print out in 2 sections and tape them together. Then cut out and tape onto fb wood and etch w/ ruler and sharp OLFA or X-ACTO knife. And marking the slots is a lot easier before the board is tapered.

This is what I do to and it works perfectly, but after I print it out, I just tape it to the board with some masking tape and slot away in my miter box instead of etching with a knife. Works perfectly for me

[Woodenspoke]

Even though these programs work there is two issues.

One unless you have a very big printer you have to attach two sheets together or more. Again one misalignment and half your FB is off.

Secondly printers are never 1:1 so there is always some reduction or enlargement taking place. It is generally not enough to make any difference but still it is there. If you are someone who thinks 24.75 is the perfect scale your printout may be only 24.72 or 24.79". Some people are really picky. Then again if you are doing it this way you are not one of those people.

[Our Souls inc.]

I have marked , with a fine-point inkpen, two templates from each scale length I utilize. I used factory necks to mark them out and double checked them against guitars they weren't created with to check the accuracy. I've been able to slot FB's since then and haven't had any issues with intonation. I use theguitars to record with so intonation is incredibly important from guitar to guitar and all over the neck. Always double/triple check your slots against a known good scale before commiting to the saw. Pencil marks can be erased , saw marks not so much so.

and to answer your original question :

: "as accurate as you want your notes" .

[Southpa]

One unless you have a very big printer you have to attach two sheets together or more. Again one misalignment and half your FB is off.

Taping 2 sheets of paper together??....c'mon

Secondly printers are never 1:1 so there is always some reduction or enlargement taking place.

Now where the hell did you hear that!?

[DC Ross]

Secondly printers are never 1:1 so there is always some reduction or enlargement taking place.

Now where the hell did you hear that!?

Common knowledge. I know there are a few lucky people out there, but every printer I've owned has done this.

[sam_c]

maybe desktop A4 printers, but not every printer. We use A0 plotters and they print 1:1, no question about it.

[Prostheta]

My laser printer prints 1:1 direct from my CAD package happily. I corroborate this with every schematic print I do by having a light grey 1/10cm gridding. Of course, YMMV between types, brands and drivers.

[Woodenspoke]

One unless you have a very big printer you have to attach two sheets together or more. Again one misalignment and half your FB is off.

Taping 2 sheets of paper together??....c'mon

Secondly printers are never 1:1 so there is always some reduction or enlargement taking place.

Now where the hell did you hear that!?

Maybe my 13 years in the corporate printer industry has something to do with my extensive printer knowledge. Then 10 years in desktop support for corporate art departments helps as well. I think that qualifies me as an expert on the subject of printers at least on this forum. What you believe to be 100% 1:1 is not possible, its close enough for a template is what I did say. Go into any print shop and ask them if they could print a 100% 1:1 print out and they will either lie right to your face or tell you it will be close but 100% accuracy is not obtainable on a laser printer or copier.

A FB scale is well over 17 inches so do the math...maybe you do have a large format 13 x 19" printer in your house great for you but I doubt may others do. So they have to tile the output and use tape.

[solomon684]

I have a cannon photo printer (ip6600 iirc) and I first printed out a 25.5" scale on three sheets, overlapped 2-3 frets on each sheet to get it lined up perfectly, taped it together, and compared to an unfretted LMII 25.5" fretboard. Matched perfectly. Tried the same thing on an old 1960s Teisco bass with a weird scale length (I think it was 28.75") and another perfect match. Is it that good of a printer, or is it off by some immeasurable amount? In which case it probably wouldnt matter too much. Im now using this method of using CAD and printing for a 26.5" 7-string template because it has worked so far

[Prostheta]

As with all things - your mileage may vary. If your printer insists on printing gaining 1cm every metre then reduce the output size to 0.99009900990099009900990099009900990099009900990099009900990099009900990099% (or thereabouts to make sure).

[Woodenspoke]

My point is when a machine cuts a template it is as accurate as you can get. A plotter may be as accurate as a CNC machine if you need a printout. I have never worked with plotters so I am just guessing.

Can you really eyeball a few thousands over that distance, it isn't possible working from a floppy piece of paper held together with tape. Again my point is the only way to eliminate human / printer error is buy a precut template or very long calipers. In fact you get two with every purchase. I am not advocating you cheapskates run to the store and buy a template. For my needs I dont have to second guess myself and slotting takes minutes not hours.

The title of this is accuracy and that is what I am discussing as accurately as possible. Or just buy a pre slotted board cut with.......here it comes.......a template..LOL

[Tim37]

when i was drafting i had access to plotters that where as acurate as a cnc also capable of doing large prints without tape(i think a role of paper was a couple of hundred ft and was 17, 36, 42, or 54 inches wide) but the paper is where you run in to problems paper shrinks and streches. i have had to deal with a lot of plots over the years and trust me they do change shape. now if it was a fresh plot on good paper i would say it would be in acceptable toleranceses but i wouldnt let a plot sit around for long befor using it. also i would be skeptical about using taped to gether plots off a desk top printer.

Edited April 12, 2010 by Tim37

[Prostheta]

Plotters, vinyl cutters, CNC, laser plotters, etc. are meant by design to translate a scaled representation and create a real-world result with predictable dimensions. A SOHO-level printer is far less likely to have tight real-world tolerances. I'm sure that you could illustrate the differing levels of quality Spoke, but I think it is outside the bounds of these questions and you have already touched on most of these anyway which is great.

I suppose my point is that a printer is less geared towards consistency in terms of absolute scale, whereas a machine designed to produce a scaled product is. To go back to the OP - consider the lack of tolerance in the other parts of the equation....the saw, the sawing method, fretwire tolerance, installation tolerance, substrate movement and inconsistency (it's wood!) and you can easily see something which may measure in 1/10ths of a millimetre. Given the other imperfections of our chosen instruments, marginal fret placement tolerances are insignificant.

I personally would say that half a mm is an acceptable tolerance for work done by hand using reasonable tools, reasonable experience and reasonable care. Above that, great - but there are diminishing returns. Below that and yes....perhaps consider practice ;-) I'm sure the manufacturing tolerances on mid to high end commercial instruments aren't too far off that mark and even if they are then I bet it makes more of a cosmetic difference to the trained perfectionist's eye than a defect in the intrinsic point of the product in the first place.

[ElRay]

What you believe to be 100% 1:1 is not possible, its close enough for a template is what I did say.

I think this is the key point. The ultimate accuracy of the printer isn't super important, but the printer's precision is. As long as any error is consistent, your fretboard will be suitable. As others have said, you may get a 25.49" or a 25.59" fretboard, but as long as you don't have significantly different %-errors at different locations, your fretboard won't throw-off your intonation.

Ray