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Re: Stewmac shims

Posted: Fri Nov 20, 2020 4:51 pm
by schoolie
Put a 1.0 and 0.25 in my AVRI Jag. I like the sound with the higher break angle...and the strings clear the trem screws.

Re: Stewmac shims

Posted: Tue Nov 24, 2020 7:42 pm
by Norrin Radd
I’m putting together my 1st JM partscaster. Is a shim recommended for optimal setup? And if so, what is the rationale? Sorry for the n00b questions. :whistle:

Re: Stewmac shims

Posted: Tue Nov 24, 2020 8:25 pm
by Larry Mal
Norrin Radd wrote:
Tue Nov 24, 2020 7:42 pm
I’m putting together my 1st JM partscaster. Is a shim recommended for optimal setup? And if so, what is the rationale? Sorry for the n00b questions. :whistle:
Not at all.

So, Jazzmasters were kind of designed around the concept of heavy strings, jazz players tend to use those and when the Jazzmaster was released there weren't any lighter sets as we understand them today.

The bridge tends to want more pressure on it than what today's light string gauges provide. Adding a shim gets you there.

Now, you might use a different bridge like a Mustang or a Mastery, which don't need as much pressure to keep the saddles in place like a traditional Jazzmaster bridge.

However, some Fenders are made with shallower neck pockets, and so you might not be able to get the action low as you might like it. You'll know because the bridge hits the top of the guitar, and you still wish you had lower action. This is when you need a shim, also.

Me, I took a cue from Gibson and other set neck guitar makers, who absolutely have to put an angle on those necks otherwise the entire guitar might not work and you can't really fix it. So over the years I came to conclude that a neck angle is best on all guitars, so I just put shims on my Fenders anyway.

Re: Stewmac shims

Posted: Wed Nov 25, 2020 7:27 am
by Norrin Radd
Larry Mal wrote:
Tue Nov 24, 2020 8:25 pm
Norrin Radd wrote:
Tue Nov 24, 2020 7:42 pm
I’m putting together my 1st JM partscaster. Is a shim recommended for optimal setup? And if so, what is the rationale? Sorry for the n00b questions. :whistle:
Not at all.

So, Jazzmasters were kind of designed around the concept of heavy strings, jazz players tend to use those and when the Jazzmaster was released there weren't any lighter sets as we understand them today.

The bridge tends to want more pressure on it than what today's light string gauges provide. Adding a shim gets you there.

Now, you might use a different bridge like a Mustang or a Mastery, which don't need as much pressure to keep the saddles in place like a traditional Jazzmaster bridge.

However, some Fenders are made with shallower neck pockets, and so you might not be able to get the action low as you might like it. You'll know because the bridge hits the top of the guitar, and you still wish you had lower action. This is when you need a shim, also.

Me, I took a cue from Gibson and other set neck guitar makers, who absolutely have to put an angle on those necks otherwise the entire guitar might not work and you can't really fix it. So over the years I came to conclude that a neck angle is best on all guitars, so I just put shims on my Fenders anyway.
Hey - thanks for the info! That makes a lot of sense. As a guy who has pretty much played mostly Stratocaster‘s and telecasters, do you think it makes sense to maintain the same gauge strings as I am used to, or would you recommend an increased gauge size due to the nature of the jazzmaster? I currently use 9 - 46s on my Strats & Teles. I’m thinking a 10- 52 set for the jazzmaster might be the way to go? Plus a shim? FWIW, I’m used to having to install shims. One of my Strats, the one that actually plays the best, has a StewMac .25 in it.

Thanks for any advice! I’m actually really excited to get this thing together once all the parts arrive! :w00t:

Re: Stewmac shims

Posted: Wed Nov 25, 2020 8:03 am
by Larry Mal
Norrin Radd wrote:
Wed Nov 25, 2020 7:27 am


Hey - thanks for the info! That makes a lot of sense. As a guy who has pretty much played mostly Stratocaster‘s and telecasters, do you think it makes sense to maintain the same gauge strings as I am used to, or would you recommend an increased gauge size due to the nature of the jazzmaster? I currently use 9 - 46s on my Strats & Teles. I’m thinking a 10- 52 set for the jazzmaster might be the way to go? Plus a shim? FWIW, I’m used to having to install shims. One of my Strats, the one that actually plays the best, has a StewMac .25 in it.

Thanks for any advice! I’m actually really excited to get this thing together once all the parts arrive! :w00t:
No, you might read in places that you have to use different gauges with Jazzmasters but that's bad and outdated advice.

With a proper setup, and a proper understanding of how to set up your offset, you can use any string gauge you might feel comfortable with. I always have personally.

When I say "proper setup", though, that might involve a shim in order to increase the pressure on the saddles, or you might consider a Mustang type bridge which is much easier to set up than the stock Jazzmaster kind with all the individual hyper-adjustable saddles, which I've never liked. There's a lot of bridge choices out there now and the only one that needs all this extra precautions with tends to be the original, vintage kind, and that's the only kind there was for decades, so a lot of what you read on the internet fails to take into account all the new equipment that simply wasn't around for most of the Jazzmaster's history.

But you should take the mindset of being able to use whatever strings you prefer and then make your guitar accommodate that, rather than have to adjust yourself around your guitar. No need to do that.

Let us know how you get on!

Re: Stewmac shims

Posted: Wed Nov 25, 2020 12:29 pm
by HarlowTheFish
Norrin Radd wrote:
Wed Nov 25, 2020 7:27 am
Hey - thanks for the info! That makes a lot of sense. As a guy who has pretty much played mostly Stratocaster‘s and telecasters, do you think it makes sense to maintain the same gauge strings as I am used to, or would you recommend an increased gauge size due to the nature of the jazzmaster? I currently use 9 - 46s on my Strats & Teles. I’m thinking a 10- 52 set for the jazzmaster might be the way to go? Plus a shim? FWIW, I’m used to having to install shims. One of my Strats, the one that actually plays the best, has a StewMac .25 in it.

Thanks for any advice! I’m actually really excited to get this thing together once all the parts arrive! :w00t:
To get a nicely dialed-in setup that works as designed, a shim is basically required unless you get a body with a pre-angled neck pocket or get extremely lucky with pocket/neck depth and it just sits in a good place. So basically just get one, odds are you'll need it - a set of the 0.5deg ones is pretty good (you can stack them if you need to), or one set of 0.5 and one of 0.25deg will give you the most flexibility.

As far as using heavier strings, you don't need to per se if you have a good setup, but you might want some because the compliance of the strings is different on the offsets, and while the tension is the same (as measured in lbs/kg) as a Strat or Tele, because there's more total string length to stretch, the whole thing feels a bit softer to play. So not needed necessarily, but you might want them anyway - try your usual set and see how you like it, you might want it to feel a bit different or more similar to how your Strats and Teles do.

Re: Stewmac shims

Posted: Wed Nov 25, 2020 5:17 pm
by Norrin Radd
Larry Mal wrote:
Wed Nov 25, 2020 8:03 am
But you should take the mindset of being able to use whatever strings you prefer and then make your guitar accommodate that, rather than have to adjust yourself around your guitar. No need to do that.

Let us know how you get on!
Will do! I suppose I should start my own thread over in the projects forum. I'll report there as the pieces come in and she gets herself together!

Too everyone - thanks for all your help & advice!

Re: Stewmac shims

Posted: Wed Nov 25, 2020 5:24 pm
by timtam
Norrin Radd wrote:
Tue Nov 24, 2020 7:42 pm
I’m putting together my 1st JM partscaster. Is a shim recommended for optimal setup? And if so, what is the rationale? Sorry for the n00b questions. :whistle:
First question ... you're planning on using the rocking bridge, right ? The setup requirements for a fixed bridge like Fender's AOMs or Mastery are somewhat different.

Assuming rocking bridge, what you are trying to achieve is sufficient string-saddle downforce. That can be achieved in several ways. In an ideal world we would have a calculator for what combination of things get you to where you need to be downforce-wise. No single factor like heavier gauge strings are absolutely necessary - you can get by with regular gauges if you do other things right. It also depends to some extent on how hard you play (whether strings stay in their grooves .. Mustang-style bridges have deeper grooves if you play heavy, but don't usually have radius adjustment), and how much you plan on using the trem.

Sufficient string-saddle downforce gives you the string-saddle friction necessary for consistent trem function, and also to minimise potential sources of bridge rattle. That often requires an angled neck pocket (built into some modern models, or via a tapered shim), to get the bridge high enough for good string break angle - along with sufficient string gauge (string tension) that break angle is what gets you good downforce on the rocking bridge.

It sounds a bit complicated but it's really no more complex than say setting up a floating strat trem, or the myriad inconclusive discussions about Les Paul top-wrapping/break angles/stop bar height. The principles are actually more straightforward than for those.

Re: Stewmac shims

Posted: Mon Nov 30, 2020 5:06 am
by jorri
Norrin Radd wrote:
Tue Nov 24, 2020 7:42 pm
I’m putting together my 1st JM partscaster. Is a shim recommended for optimal setup? And if so, what is the rationale? Sorry for the n00b questions. :whistle:
From what parts?
I think I asked guitarmill once if they would make a shallower neck pocket and seemed ok.
I asked Warmoth and they say no nothing, absolutely nothing can be changed, use our unusually deep neck pockets and slightly wrong placements of everything. Thats right they seem to need shims even more than stock fenders.

Cant really get things too high very easily. I think with expected builds you could easily get away with having the body built 2mm higher pocket. Even an angle if they can (?). If 95% need a shim for steepness, and literally no one asks for one to make a shallower angle that is reasonably safe solution (the 5% wouldnt hurt either). Shims were meant for margins of errors but if nearly ever guitar needs one it should be done in the machining process.
Think a newer Fender model does this but been out the loop with those for a bit.

Re: Stewmac shims

Posted: Mon Nov 30, 2020 5:34 am
by gila_crisis
gila_crisis wrote:
Thu Nov 19, 2020 7:01 am
I've ordered a 0.5 shim from Stewmac, shall be here next week.
On my MIJ JM I already have a Mastery installed, but after reading a bit of comment on the net I thought adding a shim will make the setup better.
I did almost order also a .25, but after reading a bit what people are using on JM, I see that most people install a o.5.
I'll let you know my experience as soon I've installed it.
Update: I got today my order from Stewmac, shim installation was flawless, it fitted out of the box into the neck pocket without any mods or reshaping. I still have to fine tune a bit neck curvature, but so far, I'm super happy how the guitar is setup now. The string action is a lot more balanced on the the whole neck.

Re: Stewmac shims

Posted: Mon Nov 30, 2020 7:09 am
by adamrobertt
jorri wrote:
Mon Nov 30, 2020 5:06 am
Norrin Radd wrote:
Tue Nov 24, 2020 7:42 pm
I’m putting together my 1st JM partscaster. Is a shim recommended for optimal setup? And if so, what is the rationale? Sorry for the n00b questions. :whistle:
From what parts?
I think I asked guitarmill once if they would make a shallower neck pocket and seemed ok.
I asked Warmoth and they say no nothing, absolutely nothing can be changed, use our unusually deep neck pockets and slightly wrong placements of everything. Thats right they seem to need shims even more than stock fenders.

Cant really get things too high very easily. I think with expected builds you could easily get away with having the body built 2mm higher pocket. Even an angle if they can (?). If 95% need a shim for steepness, and literally no one asks for one to make a shallower angle that is reasonably safe solution (the 5% wouldnt hurt either). Shims were meant for margins of errors but if nearly ever guitar needs one it should be done in the machining process.
Think a newer Fender model does this but been out the loop with those for a bit.
A lot of the newer offsets have a 1% angled neck pocket, starting with the AV '65 models, but also some of the Mexican models, the American Professional series, and the Elite series.

Re: Stewmac shims

Posted: Mon Nov 30, 2020 9:50 am
by jorri
adamrobertt wrote:
Mon Nov 30, 2020 7:09 am
jorri wrote:
Mon Nov 30, 2020 5:06 am
Norrin Radd wrote:
Tue Nov 24, 2020 7:42 pm
I’m putting together my 1st JM partscaster. Is a shim recommended for optimal setup? And if so, what is the rationale? Sorry for the n00b questions. :whistle:
From what parts?
I think I asked guitarmill once if they would make a shallower neck pocket and seemed ok.
I asked Warmoth and they say no nothing, absolutely nothing can be changed, use our unusually deep neck pockets and slightly wrong placements of everything. Thats right they seem to need shims even more than stock fenders.

Cant really get things too high very easily. I think with expected builds you could easily get away with having the body built 2mm higher pocket. Even an angle if they can (?). If 95% need a shim for steepness, and literally no one asks for one to make a shallower angle that is reasonably safe solution (the 5% wouldnt hurt either). Shims were meant for margins of errors but if nearly ever guitar needs one it should be done in the machining process.
Think a newer Fender model does this but been out the loop with those for a bit.
A lot of the newer offsets have a 1% angled neck pocket, starting with the AV '65 models, but also some of the Mexican models, the American Professional series, and the Elite series.
cheers i don't keep track of which

Re: Stewmac shims

Posted: Mon Nov 30, 2020 8:23 pm
by Norrin Radd
jorri wrote:
Mon Nov 30, 2020 5:06 am
Norrin Radd wrote:
Tue Nov 24, 2020 7:42 pm
I’m putting together my 1st JM partscaster. Is a shim recommended for optimal setup? And if so, what is the rationale? Sorry for the n00b questions. :whistle:
From what parts?
I think I asked guitarmill once if they would make a shallower neck pocket and seemed ok.
I asked Warmoth and they say no nothing, absolutely nothing can be changed, use our unusually deep neck pockets and slightly wrong placements of everything. Thats right they seem to need shims even more than stock fenders.

Cant really get things too high very easily. I think with expected builds you could easily get away with having the body built 2mm higher pocket. Even an angle if they can (?). If 95% need a shim for steepness, and literally no one asks for one to make a shallower angle that is reasonably safe solution (the 5% wouldnt hurt either). Shims were meant for margins of errors but if nearly ever guitar needs one it should be done in the machining process.
Think a newer Fender model does this but been out the loop with those for a bit.
It’s an MJT body and a Musikraft neck. This is my 1st time so I’m expecting to make lots of mistakes and fuck up a couple things before I get it right! :jacked: Probably bought all the wrong hardware. :wtf:

Re: Stewmac shims

Posted: Wed Dec 02, 2020 5:55 am
by jorri
Norrin Radd wrote:
Mon Nov 30, 2020 8:23 pm
jorri wrote:
Mon Nov 30, 2020 5:06 am
Norrin Radd wrote:
Tue Nov 24, 2020 7:42 pm
I’m putting together my 1st JM partscaster. Is a shim recommended for optimal setup? And if so, what is the rationale? Sorry for the n00b questions. :whistle:
From what parts?
I think I asked guitarmill once if they would make a shallower neck pocket and seemed ok.
I asked Warmoth and they say no nothing, absolutely nothing can be changed, use our unusually deep neck pockets and slightly wrong placements of everything. Thats right they seem to need shims even more than stock fenders.

Cant really get things too high very easily. I think with expected builds you could easily get away with having the body built 2mm higher pocket. Even an angle if they can (?). If 95% need a shim for steepness, and literally no one asks for one to make a shallower angle that is reasonably safe solution (the 5% wouldnt hurt either). Shims were meant for margins of errors but if nearly ever guitar needs one it should be done in the machining process.
Think a newer Fender model does this but been out the loop with those for a bit.
It’s an MJT body and a Musikraft neck. This is my 1st time so I’m expecting to make lots of mistakes and fuck up a couple things before I get it right! :jacked: Probably bought all the wrong hardware. :wtf:
Definately take slow and search most of the steps....overestimate the budget.
But can say the guitar (Warmoth) i did fuck up a lot of things of ten years ago is still my main guitar haha, and still evolves now and again.
Then my mistakes include still having a snapped tuner screw, always the screws, maybe i should have looked at how to use screws and what pilot holes are. Seems inconsequential now. The other fuckup is maybe the fact its Warmoth and placement of most things is a bit different on purpose.

Nonetheless this forum would be very helpful.

Either way, basically nearly every fender offset has a piece of something that looks like an offcut from the factory bin in it...since their conception. Shims arent that bad, demonstrably good, even. Its just if the chance is there why build wrong then fix if can build right.

Re: Stewmac shims

Posted: Thu Dec 03, 2020 2:18 pm
by ChrisDesign
I saw a Crimson Guitars video where Ben claims Fender ‘always shins their necks’. Maybe he’s exaggerating, but high end Fenders have a micro shim built in. I’ve also heard Leo designed the Jazzmaster to be shimmed. Either way, shims are ok.