Necks Shimmed by the Factory? WTH?

[ajkula66]

and I assume set necks too.

You would be wrong.

I'm not saying it never ever happened, but a standard practice it was not by any stretch of imagination.

 

[ScotJam Bassie]

I shimmed the neck on my new Yamaha JP II six string with a sanded down credit card, plays like a dream now. I would not have expected a $3,000+ bass to need shimmed, but there it is! I also shimmed the neck on my Godin A5 Ultra fretless, but the bridge is not adjustable on that bass. Oh, and my ‘74 P as well…. Embrace the shims!

 

[gln1955]

I have been buying instruments for several decades now and have never seen on come from the factory with a shim. I think you are getting all lathered up over perception and heresay, and not reality.

Are you saying all of us who have actually seen shims in our new basses are making it up?

 

[Freekmagnet]

But using shims is not standard operating procedure for you. If you are cutting wood within .003"-.006" of spec, I assume your intent is that the guitar will shake out without the need for shims or similar compensatory adjustments.
I would be happy to buy a shimmed instrument from a builder who I knew paid great attention to detail and is dedicated to his or her craft.

For me, building within a certain spec is more about consistency from part to part. It just takes more of the thinking and guesswork out of the job. At the end of the day, building a musical instrument from scratch entails a lot of heartbreaks and compromises. Guitars are very complicated pieces of machinery, and the materials, the engineering, and the building process are not always cooperative. The end goal of a luthier is to produce something that looks great, plays great, and sounds great. Adding a shim (if necessary) is just part of the adjustment process, and I don't think it's anything more than that. Someone else in the thread pointed out adjustable saddles as a comparison, and think that's fair. Using the argument that every instrument made should serve as an example of absolutely perfect manufacturing that never ever requires a shim, then we shouldn't need adjustable saddles because everything will be built to make the strings the perfect height and length just by screwing the neck to the body. Heck, let's get rid of the truss rod while we're at it, too.

If instead of a matchbook cover, someone found a small shim made of wood perfectly machined to fit the neck pocket to tilt the neck to .5º and it a branded stamp saying "Official Lakland Neck Pocket Adjuster", and as long as they understood that the shim was necessary part of the manufacturing process, they'd probably think that shim was a work of bass building genius. Personally, I wouldn't waste my time machining a special part to use as a shim - I usually use a piece of 120 grit sandpaper cut to size with a pair of scissors.

While using shims for me an exception, keep in mind, I'm not building 10,000 guitars a month - I'm just building a few per year. You're more likely to find a shim in an Ibanez simply because Ibanez makes a lot of guitars. TBH, the manufacturing tolerances at the large factories is astonishingly good. I've often said that since I've started building instruments, I am less impressed by the quality of a $10,000 instrument, and more impressed by how good a guitar they can put out on the sales floor for under $500.

 

[Jazzdogg]

How many basses have you made?

 

[Nenor]

Using the argument that every instrument made should serve as an example of absolutely perfect manufacturing that never ever requires a shim, then we shouldn't need adjustable saddles because everything will be built to make the strings the perfect height and length just by screwing the neck to the body. Heck, let's get rid of the truss rod while we're at it, too.

Not at all the same. Adjustable saddles and truss rod are for fine tunning the instrument for best performance, as pickup height screws. They are meant to be adjusted. Neck to body angle is a constructive parameter in the building process. It is part of the instrument design. This is what allowing the saddles to be adjusted. Can you see the difference?

 

[Freekmagnet]

Not at all the same. Adjustable saddles and truss rod are for fine tunning the instrument for best performance, as pickup height screws. They are meant to be adjusted. Neck to body angle is a constructive parameter in the building process. It is part of the instrument design. This is what allowing the saddles to be adjusted. Can you see the difference?

Nope. I don't see the difference.

 

[/\/\3phist0]

I was surprised, but it bothered me, not because I thought they were perfect, but because I already knew that they weren't. I expect and have seen flaws in mass produced instruments. But, if you get lucky with your purchase, you can get a decent instrument that you can tweak and improve over time.

Then I hear this about shims and now I realize that these manufacturers that I don't trust to build a proper neck or do a proper fret job are shimming they before shipment? My thinking is that if the bass needed a shim brand new, then that neck was suspect to begin with and will most likely get worse with years of use.

That is most bolt on necks, from (insert major name mfg) that are produced, it’s as common that there is a shim, than there is not. I’ve worked on thousands of instruments. I agree it’s an addressable issue with mfg tolerances, but it is the way it is.

 

[CryingBass]

If a shim fell in the forest would anyone hear it?

 

[jmlee]

Works fine for me too. I had to put that shim on my p bass as per my avatar and it now plays like a dream :

image fhoto

Finally! Air Canada is useful for something!

 

[Gervais Cote]

Finally! Air Canada is useful for something!

 

[Jeff Scott]

...a haas CNC mill...

Have you noted that Haas has never done all that great in the Formula 1 world? Perhaps a different brand of CNC mill would be better for your example, here.

 

[Kubicki Fan]

Luckily, consumers have a choice in whether to keep a new bass with a neck shim. Luckily, there are plenty who don't mind a shim on a new bass, and the vendors will always be able to move them along.

None of my basses has a neck shim. If one of them had developed a need for a shim, it would get one.

Warmoth has really impressed me with the tight tolerances in their products. No need for shim, almost no need for neck bolts even.

 

[sunbeast]

I've heard it said that a strip shim that disrupts full heel contact with the pocket can cause all kinds of weird tone and sustain and dead-note issues, because the neck and body are no longer vibrating as a unit. So if a shim is needed, it's best to use one that totally covers the neck heel, like the ones Stewmac sells. Can anyone confirm or deny this? Anything to it?

FWIW, at least 15 and maybe 20 Fenders have come my way since the mid 1970s, and I have yet to see one that had a shim.

I'm surprised you've had so many Fenders without shims, as I've seen them in probably a quarter or more of the ones I've opened up!

My take is that you don't actually want to be losing energy from the neck into the body in a typical solid-bodied guitar (unlike an acoustic or even semi-hollow instrument). Unlike the thin body top of an acoustic instrument which is designed to vibrate and enhance sound via the specialised interface of the strings through the bridge, the massive (and often relatively soft wood) body in many solidbody guitars is more likely to suck energy than anything IMO and the neck joint needs only to be firm for stability purposes and not so much for sustain purposes. Consider a banjo, which has a neck with a very solid neck interface with the body and very little sustain (of course most of that energy is lost to the body at the bridge, as designed!). I've also always found resonant deadspots to follow the neck in my experience- and the fix for a neck with a deadspot to be changing the mass at the headstock end of the neck since the neck is where most of the energy is held or lost while changing mass at the body side (like changing the bridge) seems to have no effect on deadspots. In any case I've never found a small shim to noticeably decrease sustain in my experience, and it may even have enhanced it in some cases

Not at all the same. Adjustable saddles and truss rod are for fine tunning the instrument for best performance, as pickup height screws. They are meant to be adjusted. Neck to body angle is a constructive parameter in the building process. It is part of the instrument design. This is what allowing the saddles to be adjusted. Can you see the difference?

Fender created the bolt-on guitar design specifically to simplify and speed up manufacture and assembly vs the alternatives. Part of that was building in enough “slop” to the fit of the respective parts that an assembler in the factory could grab any neck and mate it with any body with minimal finish fitting required. Because of that built-in slop, sometimes shims were necessary as part of the assembly/setup of a given instrument. Based on the inconsistency of parts on many import instruments, I would guess the “slop” part is still part of the design.

 

[pcake]

Have you noted that Haas has never done all that great in the Formula 1 world? Perhaps a different brand of CNC mill would be better for your example, here.

my husband, who works on scientific stuff like particle accelerators and has worked on medical equipment, small aerospace parts and more, has usually used a CNC mill, as that's what the companies usually had. in all the companies he's worked for, most (or all) of the mills were haas, and if they're not the best with the tightest tolerances, they're like i think of steinway pianos.

apparently the problem may be that gene haas wanted (wants?) his own formula one race team. he wasn't allowed to do so for a few reasons (we looked it up) as apparently they didn't feel he was serious about racing - they thought he just wanted to use them as an advertising platform. also i gather the cars had issues. as far as i can tell from a quick search, haas machines can be used for other teams' forumla one cars.

 

[Geri O]

If a shim fell in the forest would anyone hear it?

(Continuing along the lines of your thought….)

If shins were accepted as a common practice, would anyone post about it again?…

 

[Jeff Scott]

my husband, who works on scientific stuff like particle accelerators and has worked on medical equipment, small aerospace parts and more, has usually used a CNC mill, as that's what the companies usually had. in all the companies he's worked for, most (or all) of the mills were haas, and if they're not the best with the tightest tolerances, they're like i think of steinway pianos.

apparently the problem may be that gene haas wanted (wants?) his own formula one race team. he wasn't allowed to do so for a few reasons (we looked it up) as apparently they didn't feel he was serious about racing - they thought he just wanted to use them as an advertising platform. also i gather the cars had issues. as far as i can tell from a quick search, haas machines can be used for other teams' forumla one cars.

So, it's just Gene's bad luck, or something.

Haas F1 did surprisingly well in their first year in the series. It would be nice to see a US team do well in F1, someday.

 

[Geogio]

I prefer to use the maple shims from stew Mac. They come in flat thicknesses or selected degrees of angle.

I have used a playing card for a shim once, I made sure it was the Ace of Spades.

 

[Kubicki Fan]

A shim is a stop-gap measure.

 

[TheArchitect]

Are you saying all of us who have actually seen shims in our new basses are making it up?

I'm saying in 35 years I have NEVER seen a shim in a new instrument. Ever. Rarely in a used instrument. Once that I can recall in that time