Neck shim material?

[Manton Customs]

[quote name='EBS_freak' timestamp='1472318048' post='3120349']
I can't believe this conversation is happening...

Use pretty much anything as a shim, credit card, vaneer, whatever... it makes zero difference to tone or anything like that - that's all a myth. If the screws are tight enough, the job is done.

And a shim is a common practice utilised by many luthiers, including those that are considered "world class",I would certainly argue that it is not a failing in it's manufacture.
[/quote]

Why, what's wrong with discussing preferences and offering advice based on experience? Nobody is debating anything or dictating how it should be done .

I also think you're misunderstanding a bit, or at least jumping to conclusions: I don't believe anyone here has mentioned tone and I'd agree with you, it's not going to alter the sound of the bass . However certain materials will hold up better over time (card will compress for example).

I believe you're last paragraph is referring to my post earlier. I stand by that fully. There is nothing wrong with using a shim to resolve an issue. However no professional luthier is going to use a shim on a new build, if they did then they miscalculated. There is no good reason to rely on a shim if you're starting from scratch, the angle should be milled into the neck pocket or the neck itself. Or in the case of Fender style instruments no angle but the pocket cut to the correct depth.

Edited August 27, 2016 by Manton Customs

[Andyjr1515]

[quote name='Manton Customs' timestamp='1472330248' post='3120438']


Why, what's wrong with discussing preferences and offering advice based on experience? Nobody is debating anything or dictating how it should be done .

I also think you're misunderstanding a bit, or at least jumping to conclusions: I don't believe anyone here has mentioned tone and I'd agree with you, it's not going to alter the sound of the bass . However certain materials will hold up better over time (card will compress for example).

I believe you're last paragraph is referring to my post earlier. I stand by that fully. There is nothing wrong with using a shim to resolve an issue. However no professional luthier is going to use a shim on a new build, if they did then they miscalculated. There is no good reason to rely on a shim if you're starting from scratch, the angle should be milled into the neck pocket or the neck itself. Or in the case of Fender style instruments no angle but the pocket cut to the correct depth.
[/quote]
+1 on all of this

This is a discussion, not an argument

There is nothing wrong with using a shim and its need can be caused by a number of factors including: new hardware; timber movement; ease or cost of manufacture; error

In most cases, a shim wouldn't be designed into a build. If so, a through neck or glued neck would present some issues!

A shim will not affect the tone

You can use a shim either to raise the whole neck or to angle it. Adding an angle to the neck by shimming at heel or toe has a much bigger effect per mm of shim than a full shim

In terms of the material, it can be anything that will not deteriorate or move/crush over time...which I think was the original question

Edited August 28, 2016 by Andyjr1515

[mcnach]

[quote name='darkandrew' timestamp='1472229327' post='3119691']
I know it's already been discussed, in a previous thread,that a partial shim across the last screws can lead to the neck bowing due to the part of the neck that's above the void in front of the shim being pulled into it and creating a ski jump at the end of the neck. I've been thinking about this - is this actually likely as it's not just the neck that would have to bow but also the truss rod that's going through it?

I ask this because I've just taken ownership of an Ernie Ball Sterling bass whose E string saddle is as low as it can go but needs to go a bit lower, and so I was thinking about putting a shim in the neck pocket and was wondering whether to use the Ernie Ball partial shim or make my own full pocket shim out of maple veneer.
[/quote]

partial shims are fine... I very much doubt that that extra cm occupied by the shim can be the cause of a 'ski jump'. Shims like that are typically used to change the neck angle. If you don't need that angle changed but you still think you need the fingerboard raised a bit, an even full pocket shim would be best, but it's less common than just needing to alter minutely the neck angle.

Edited August 28, 2016 by mcnach

[mcnach]

[quote name='HowieBass' timestamp='1472235909' post='3119754']
I had a similar problem with my Cort Curbow 5 (bought secondhand via eBay) where both the G and the low B were causing problems because I couldn't get them low enough. The saddles are of a cast design, which could have been filed for a deeper groove, but for me it was easier to raise the whole neck with a shim.
[/quote]

that's the type of situation where I'd normally use a partial shim on the bridge end of the pocket. Very thin, for a tiny increase in angle goes a long way several inches down the string towards the bridge. I haven't needed a full pocket shim ever, but I guess in some cases it can happen.

[darkandrew]

Ernie Ball USA confirmed that they fit shims on some of their basses at the factory where necessary and reassured me that they've never had any problems. So, I bought a set of shims from their online UK store - they are available in three thicknesses, from approx 0.2 mm to 0.5 mm and cost less than a pound each so I bought one of each. The shims arrived yesterday morning, a day after ordering them. The link below is to a picture I found online of one of the EBMM shims in use - the picture's not mine but the shims that arrived are identical to the one shown:

http://s6.photobucket.com/user/franlubas/media/Y2Dneckshim.jpg.html

The material is some sort if semi-rigid plastic (PE?).

I first chose to try the thinnest of the three shims but didn't really get the lift that I needed, so I then tried the middle of the three. With this installed I was able to set the bass up to spec with 0.4mm relief at the 8th fret and an action of 2.5 mm on the E string when measured at the 15th fret. Similarly, I was also able to achieve correct intonation across all four strings. So, all good. ☺

Edited August 28, 2016 by darkandrew

[mcnach]

Nice job!

[darkandrew]

[quote name='mcnach' timestamp='1472472963' post='3121344']
Nice job!
[/quote]
Thanks. It's the first time I've done this sort of thing on a bolt-on. My other basses are all neck-throughs and my guitars are all set-necks. Everytime I buy a new bass or guitar I promise myself that I will leave it as it is - I think I managed to last about 30 mins before giving in to the overwhelming urge to take this one apart and give it a thorough set up! Maybe next time.

Edited August 30, 2016 by darkandrew

[mcnach]

[quote name='darkandrew' timestamp='1472490389' post='3121531']
Thanks. It's the first time I've done this sort of thing on a bolt-on. My other basses are all neck-throughs and my guitars are all set-necks. Everytime I buy a new bass or guitar I promise myself that I will leave it as it is - I think I managed to last about 30 mins before giving in to the overwhelming urge to give this one a thorough set up! Maybe next time.
[/quote]

Ha!

but that's the thing, if you can set it up nicely, why not? And in bolt-on basses it means you have to consider neck angle as yet another variable to play with. Glad it worked out!

[Grangur]

[quote name='HowieBass' timestamp='1472307666' post='3120239']
@Norris - I'll try this with my Curbow 5 but it seemed to me that all the neck heel, in contact with all of the full pocket shim, in contact with all of the neck pocket would be the better engineering solution. I know that when people add high mass bridges with a chunky baseplate to an instrument, they often run out of travel with the saddles and the usual solution is rout the body to drop the whole bridge down by a millimetre or so... are you saying that another option is add a shim to the back of the neck pocket to tilt the whole neck backwards? From an engineering/geometry perspective there doesn't seem much difference between dropping the bridge into a shallow rout or raising the whole neck with a full shim
[/quote]
I can see your thinking behind liking the idea of the full-contact of the full pocket shim. I don't think this is a problem with a partial shim as long the connection is solid.

The difference between a full pocket shim and a partial one is with a full one, if you effectively want to lower the bridge 2mm, then you will need a 2mm full pocket shim.
If you, instead, used a partial shim, you would only need something like a 1mm shim.

Also, if you use a full shim, this is visible as a gap a the the place where you look at the neck in the pocket. If you've used a partial shim the neck touches the bottom of the body in the pocket and nothing is going to be visible.

[darkandrew]

The thing that convinced me that a partial shim would be OK was EBMM USA confirming that they use them and have never had any problems with them.

[mcnach]

[quote name='Grangur' timestamp='1472511400' post='3121773']
I can see your thinking behind liking the idea of the full-contact of the full pocket shim. I don't think this is a problem with a partial shim as long the connection is solid.

The difference between a full pocket shim and a partial one is with a full one, if you effectively want to lower the bridge 2mm, then you will need a 2mm full pocket shim.
[b]If you, instead, used a partial shim, you would only need something like a 1mm shim[/b].

Also, if you use a full shim, this is visible as a gap a the the place where you look at the neck in the pocket. If you've used a partial shim the neck touches the bottom of the body in the pocket and nothing is going to be visible.
[/quote]

probably quite a bit thinner than 1mm. I have often used business cards, which may not be the best choice as they do compress over time, but with a business card thick shim you probably get those 2mm or so already. A little shim goes a long way!

[HowieBass]

Right, experiment conducted (swapping the constant thickness full shim with a partial shim) and I've got some interesting results (assuming it isn't me fooling myself). The Curbow has a very long neck pocket that extends all the way to the pickup (which I think is in the Stingray position) so I ended up using a relatively thick shim of about the same thickness as the original full pocket shim. As expected it changed the neck angle a fair bit (not stupidly different obviously) and I got a greater range of adjustment available with the saddles. I'd previously got the G and low B saddles pretty much down to the deck so my action has now improved a fraction, in that it's lower (the bridge itself is angled back so you get less height adjustment per turn of the saddle screw than you would with a conventionally situated bridge). I think I might be getting a little note choking at the very highest frets because of the change in neck angle - I haven't changed the neck relief. This very minor note choking doesn't bother me. I don't see much change in the dead spots; I don't think they're any worse. The biggest change to my ears is the sound seems somewhat harmonically richer - this is a GOOD thing! I might just be hearing a bit more noise from the frets with the change in neck angle but I might well have changed the way the neck/body combination vibrates because there's less of a connection between the two with a partial shim. I've read more than once that bolt on neck instruments often sound brighter than neck through designs and some believe it's because the fundamental is stronger with a neck through... in other words the neck/body junction of a bolt on can favour the harmonics a bit more. I'm wondering if this is what I'm hearing? I can see why people use partial shims - they're easy to fabricate and install but I really didn't expect to hear an improvement in tone! The partial shim will be staying!

[mcnach]

[quote name='HowieBass' timestamp='1472558329' post='3122066']
Right, experiment conducted (swapping the constant thickness full shim with a partial shim) and I've got some interesting results (assuming it isn't me fooling myself). The Curbow has a very long neck pocket that extends all the way to the pickup (which I think is in the Stingray position) so I ended up using a relatively thick shim of about the same thickness as the original full pocket shim. As expected it changed the neck angle a fair bit (not stupidly different obviously) and I got a greater range of adjustment available with the saddles. I'd previously got the G and low B saddles pretty much down to the deck so my action has now improved a fraction, in that it's lower (the bridge itself is angled back so you get less height adjustment per turn of the saddle screw than you would with a conventionally situated bridge). I think I might be getting a little note choking at the very highest frets because of the change in neck angle - I haven't changed the neck relief. This very minor note choking doesn't bother me. I don't see much change in the dead spots; I don't think they're any worse. The biggest change to my ears is the sound seems somewhat harmonically richer - this is a GOOD thing! I might just be hearing a bit more noise from the frets with the change in neck angle but I might well have changed the way the neck/body combination vibrates because there's less of a connection between the two with a partial shim. I've read more than once that bolt on neck instruments often sound brighter than neck through designs and some believe it's because the fundamental is stronger with a neck through... in other words the neck/body junction of a bolt on can favour the harmonics a bit more. I'm wondering if this is what I'm hearing? I can see why people use partial shims - they're easy to fabricate and install but I really didn't expect to hear an improvement in tone! The partial shim will be staying!
[/quote]

I think your change in action may be more responsible for the changes you hear. If there's minor choking on the higher frets, there will probably be other effects with strings vibrating and hitting the frets at other locations in ways that are not obvious 'choking' but resulting in a change of the sound. The bass will probably be more responsive to how light or hard you pluck too, because of that. Do you notice something like that?

[HowieBass]

[quote name='mcnach' timestamp='1472561939' post='3122110']
I think your change in action may be more responsible for the changes you hear. If there's minor choking on the higher frets, there will probably be other effects with strings vibrating and hitting the frets at other locations in ways that are not obvious 'choking' but resulting in a change of the sound. The bass will probably be more responsive to how light or hard you pluck too, because of that. Do you notice something like that?
[/quote]

The change in action hasn't been massive - talking perhaps 1/64" at the most with all of the strings (say going from 5/64" to 4/64" for the G). The strange thing is I'm finding the A string as the one where I notice the tone better and that's always been the one that had plenty of adjustment available in saddle height with it being in the centre. It's always sounded better when played harder but I'm not one to dig in and I've not changed how I play it. I did wonder if it's a bit more fret noise but it almost sounds more than that somehow. Whatever the reason, I like it!