Arrrgh: I killed the fingerboard - whiny post

[Toddler]

I ordered a 17" scale fingerboard for the 1/2 size guitar I'm working on. Since the slots need to be accurate to .002" or so, it seemed like a good idea. But the company I ordered from only had Ukulele blanks in that scale size. Those are too narrow since a Ukulele has only 4 strings, but I couldn't find anyone else who would do a 17" scale.

I figured I'd taper it and put trim on either side to make it wide enough for 6 strings, but I tapered it wrong. :eusa_doh: Last night I tried to transfer the slot pattern to a standard sized maple board and in 2 and a half hours I got 19 fret slots right and then messed up the 20th. I need 21 slots counting the zero fret slot/mark. :BangHead: Of course I also messed up the original board I was using as a template, so I can't tell which way it's off :slap:

. . . web search

LMI will slot a 17" scale onto a standard width guitar fingerboard. Ordered one today. . . and I wimped out too, after seeing how hard it was to slot maple to within a couple of 100ths of an inch, I ordered two 25" scale fingerboards as well. That way I can only mess up the woodworking, not the math on my next couple of guitars. :drunken_s

I HATE screwing up a critical piece. It'll be a week before I get the replacement. Guess I'll just work on the pick up and control cavity/cut outs until then. I'll also make a full sized template again and be more careful tapering the new board! ! ! ! ! Maybe measure 5 times, taper, uh, once ?

 

[DavidF]

That sucks Todd - sorry. If you're anything like me, you'll be asking yourself why you screwed that up, for the next week and everytime you see it in the scrap bin:cry:

 

[cpowell]

Sorry to hear about the mistake. At least it happened on a demanding procedure.

Thinking out loud, the work you're producing sounds like it requires precise positioning. It seems like an LVDT or some other very accurate positioning device (Wixey gauge, maybe?) built into the stop block on a precision miter fence would help. It would certainly provide the accuracy you need.

Chuck

 

[Toddler]

Hi Chuck,

I need to cut the slots to .022" or .023". You can buy a blade to do that, but most hobby people use a gents saw. But my miter guide was too loose and I messed it up.

If I decide to do some fingerboards by hand, I'll just have to build a simple miter box with a couple of adjustable blade guides so I can control the depth and keep the blade at 90 degrees. I'd also mount a sliding template or an 18" vernier caliper so I could measure from my zero fret cut.

Simple to make! Coulda. . . shoulda . . . didn't. On this one I could have glued the old board onto the new one and cut through it into the new fingerboard for a perfect match, but I didn't :roll:

Live and learn.

Todd

 

[JohnW]

Feeling your pain Todd. You might check out Kathy Matsu****a's web site. Could be mistaken but I think she posted a method of doing this. If this link doesn't work, goggle her name. Kathy Matsushita's "Amateur Luthier" Page
If I'm not supposed to post web links someone let me know. I'm "new".

My board came pre-slotted so this was one issue I didn't have to deal with. But she has been a big help to me showing many other techniques...and building custom tools.

Thanks for the welcome today and good luck with the guitar.

John W

 

[froglips]

Living in the same town as Todd, I now know what that scream of agony was the other day.

Last time I heard something so awful, was when my friend cut dovetails on a 36" x 60" toy box.... backwards.

Might check local antique stores and auctions. Lots of times they are selling really old guitars cheap. Could get a deal on something to use or use as a template.

Jim

 

[Travis Porter]

That sucks, it is never a pleasurable moment. How many times I have measured a board twice, thrice, etc and realized after I cut it two short that I had buried an inch on the ruler.....

Any one that never screws up never does anything.

 

[jeff...]

Todd do you do full sized electric 4 string bass giters?

 

[Toddler]

Some pics

Jeff,
All I do is make a lot of sawdust and keep my wife's car out of the garage.
This is my first try at building an electric guitar, but I'm having so much fun I'll do a full sized one next. This on will only have a non-adjustable Martin style truss rod. The next ones will need an adjustable truss rod.

This is as far as I've gotten on Eli's. All that time and it's just the rough shape. :lol: You can't see it, but there is a channel inside it for wiring. I'll be starting to drill/router our the pick up and control cavities this week and also will start carving the body. I don't want to taper or carve the neck until I have an exact fretboard placement. You can't tell, but the top is maple, the back of the body is basswood, and the neck is the paduak/bubinga/maple laminate I glued up with marine epoxy. Slowly but surely . . .

 

[Tarhead]

Todd,
Not sure if this is helpful: Stewart-MacDonald: Fret scales

[FONT=Arial, Helvetica, sans-serif][FONT=Arial, Helvetica, sans-serif]Notes on fret layout[/FONT]
[FONT=Arial, Helvetica, sans-serif]The most accurate way to lay out your scale is making all measurements from the nut (using the "fret to fret" distance only to confirm your layout). Laying out frets only by measuring fret to fret will compound error. For example, if you're laying out frets by marking with a scribe and your accuracy is plus or minus 10 thousandths, you could be off by as much as 1/8 inch at the 12th fret.[/FONT]

[FONT=Arial, Helvetica, sans-serif]Measurements are given from the end of the fingerboard (face of the nut) to the center of a fret slot.[/FONT]
[/FONT]

 

[McRabbet]

Mark,

Todd sent me an Excel spreadsheet with the fret positions given as distances from the nut. I set the scale and precision in my TurboCAD drawing and laid them out for him as a series of overlapping rectangles 1" high by the nut-to-fret-position distance. Because his set had the overall distance of 15.0000 inches and the 12th fret was at 10.0000 inches, I had a perfect place to split the drawing into two parts: Frets 0 - 12 cover 10.0000 inches and Frets 12 - 24 are covered by a second piece that is 5.0000 inches long, but when cut can overlay at the 10.0000 inch mark. That put it all on one sheet of paper -- I'm mailing Todd about 10 copies to cut out as patterns. (All of this took me about 8-10 minutes!)

Rob

 

[Toddler]

Hi Mark,

I actually have a 25" fret scale ruler from StewMac, and will use that on any full size guitars I build. But I want to build a 17" scale and a 20" scale guitar because those are more kid sized. I'm working on the 17" one now.

The common math would be to divide the distance left in the scale by 17.817. The 12th root of 2 gives you the 12th fret at the mid point, and that's what StewMac's calculator seems to do. It's also what I did in the spreadsheet.

On a very short scale it might be worth fudging it a little bit, say using 17.825 or something because the shorter the scale, the more relative stretching the string when you fret making it go sharp. I'm just going to use a low action and avoid jumbo frets. Besides, a five year old won't press too hard.

I broke out the microplanes to start shaping the neck today. Awsome file/planes!!!

Todd

 

[wayne]

Todd

How deep do the slots have to be, wondering if they could be cut with a laser engraver. If I had a cad or corel draw file would like to gice it a try. there's no doubt the precision is there as far as layout is concerned.

Wayne

 

[Toddler]

Wayne,

The tange varries from about .05 to .07 inches so that's how deep a slot I will cut.

I never really thought about a laser engraver, but all the small guitar shops I know of use a saw. Some have designed their own sort of radial arm saws. I have no idea what the big guys like Fender, Washburn, Gibson and such use.

Todd

 

[wayne]

Todd

How long is the piece getting cut. We have a mini epilog but limited to 18". might can fudge a little and get a 20" piece in the machine. If you can't get it any other way give me a shout.

Wayne

 

[Toddler]

Hi Wayne,

Thanks for letting me know. I had to look up what a mini-epilog is and did some reading. That's really cool! It can even cut through 1/8" thick wood to make modeling pieces or such for architects.

If you don't want to cut through, how do you adjust the depth of cut for carving? Is it trial and error based on your material?

Either way, that's a VERY cool system! I want one Of course I want a 36-40hp JD hydrostatic tractor too, and I think the tractor might be cheaper! Where do you work that you need one of those?

Todd

 

[wayne]

Todd

The laser uses graphic files that contain raster and or vector files the vectors cut through the material, raster files do the engraving. Both can be regulated by the speed and or power settings to achieve the desired affect. I'm a self-employed ASE master certified collision repair, paint and body tech. As for the laser loml is a cnc programer for a high end furniture manufacturer and this is her second job "gotta keep em busy you know" we are also fixing to add laser sublimation to the mix as she wants to produce the old retro ads metal signs and custom sublimation on metal.
The laser engraver will do various materials, also have a rotater that lets it do glass ware. your probably right about the JD be cheaper though by the time you purchase machine, graphic capable laptop and various software programs, not to mention rechargeing the CO2 tube when needed. Rather expensive hobby 'whoops" I meant to say second job

Wayne