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Mad picker

Mechanical fastening cello neck joint

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So I'm building a cello for a family member (I'm still learning a lot, so by no means will it be a master grade instrument). It's going to be black walnut back and sides, Sitka top, and hard maple neck. 

I was wondering about the neck joint though. Coming from building a few guitars, I'm used to bolt on mortise and tenon.

So my question is, is the cello neck joint (mortise & tenon, dovetail?) Strong enough, or should there be any mechanical fastening? I've heard of the dowel pins, bit I was thinking along the lines of screws, bolts, cross dowel nuts, etc.

Sorry if this was covered before, but I couldn't find anything about it.

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1 minute ago, Mad picker said:

I guess I'm just looking for peace of mind. I just don't want it to collapse when strung up.

One common method of heel reinforcement is a dowel down through the heel from the fingerboard gluing surface side. There usually is no fasteners necessary to go through the block and into the heel. This could compromise the heel strength if you try and go through the block and into the heel, in my opinion, but take that for what it's worth. The only thing you should be worrying about is an airtight fit for the neck heel into the mortise, and you could dowel reinforce the heel, as has been discussed quite a bit here. 

A good fit and good glue are what you need for that joint. You can reinforce the heel if you want, but it's not absolutely necessary to do. Cellos tend to be vulnerable right at the crook of the heel,  which is where most breaks occur. 

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The neck joint should be strong enough with no mechanical assistance, bolts, screws, dowels and the like.

Make sure the mortise is deep enough, and every surface that should touch does, and you should be set. And good fresh hot hide glue.

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I don't think that any celli are being commercially made with any mechanical fasteners in the neck. That should tell you something.

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5 hours ago, FiddleDoug said:

I don't think that any celli are being commercially made with any mechanical fasteners in the neck. That should tell you something.

Yup

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Of course, if you should want to make a neck joint in the way that the early masters did, you'll glue it onto the ribs and then whack some nails through the block into the heel once you get it off the ribs. All this fussy dovetailed mortise business came around a good hundred or so years after Tony Stradivari shuffled off his mortal coil. ;-)

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9 hours ago, JacksonMaberry said:

Of course, if you should want to make a neck joint in the way that the early masters did, you'll glue it onto the ribs and then whack some nails through the block into the heel once you get it off the ribs. All this fussy dovetailed mortise business came around a good hundred or so years after Tony Stradivari shuffled off his mortal coil. ;-)

I'm a belt and suspenders guy, so I'll think about that. Would the cello ever have to be opened up and the nails removed if the neck needs taken off?

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If I were going to use a fastener, and I think it's at least unnecessry, I would use a screw, stainless steel, and counterbore the block so that the screw runs freely through it.

I say this for two reasons:
-I've seen steel rust in place, which makes repairing such a rig much harder.
-I''ve seen the block and neck both shrink and the steel not, leaving the neck sitting loose, with a gap under it and the button broken. That's why to make it a sliding fit in the block, so the slack just loosens the screw on the inside, where it could be retightened if you really wanted to. 

It's possible, I know because I've had to do it, to take a steel rod and make a long screwdriver to go in through the endpin hole to remove a screw, IF it's not rusted in.

So if you do it, do us repair guys a favor, and do it sort of rightish, please?

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4 minutes ago, Michael Darnton said:

So if you do it, do us repair guys a favor, and do it sort of rightish, please?

I want to do it right (tight joint, no screws or bolts and all that jazz), but this will be my 3rd cello for family/close acquaintances (self taught and a lot of learning to do).  I don't expect this to end up being some 300 year old museum piece. I'm just trying to put my mind at ease after one of my instruments (bass guitar) started imploding.

Sorry for rambling! 

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20 hours ago, Mad picker said:

So I'm building a cello for a family member (I'm still learning a lot, so by no means will it be a master grade instrument). It's going to be black walnut back and sides, Sitka top, and hard maple neck. 

I was wondering about the neck joint though. Coming from building a few guitars, I'm used to bolt on mortise and tenon.

So my question is, is the cello neck joint (mortise & tenon, dovetail?) Strong enough, or should there be any mechanical fastening? I've heard of the dowel pins, bit I was thinking along the lines of screws, bolts, cross dowel nuts, etc.

Sorry if this was covered before, but I couldn't find anything about it.

I have repaired many school cellos.   Seldom is a neck broken out at the mortice.  They mostly break in the heel where the curvature is high.   I no longer do this kind of work (Thank the Lord)

There is 4" or so of heel,  that provides a great deal of torque to the neck if it is fit carefully and glued well.   There is nothing to worry about except to take a great deal of time to make the fit accurate.  I use blue chalk which is easy to see.  It washes off pretty well and also the blue color seems to fade.  

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2 hours ago, Mad picker said:

I'm a belt and suspenders guy, so I'll think about that. Would the cello ever have to be opened up and the nails removed if the neck needs taken off?

I want to make it clear that I was just being light-hearted. While it's true that the Strads, del Gesus, Amatis, and the like were originally made with necks that were glued with a simple butt joint to the rib surface and later reinforced with one or more nails, that is not the way things are done any more for the reasons Michael describes. The substantial majority of the instruments I make are for players who specialize in early music, and so I make them "old-school" with one exception - instead of a nail I use a screw. These can be backed out through the endpin hole with a long mechanic's screwdriver, which makes removing the neck a much simpler matter for a future repair person than if I had used a nail. Stainless steel or silicon bronze (what they use in wooden boats for corrosion resistance) should be the only alloys considered for this application.

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21 hours ago, Mad picker said:

I'm a belt and suspenders guy, so I'll think about that. Would the cello ever have to be opened up and the nails removed if the neck needs taken off?

A nice stainless steel 1/4-20 bolt will allow you to take the neck off without removing the top. Or, you could go in this direction:

https://uptonbass.com/instruments/ub-travel-double-bass/ub-travel-bass-lightweight-hybrid-double-bass/

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On 6/4/2020 at 6:47 PM, JacksonMaberry said:

I want to make it clear that I was just being light-hearted. While it's true that the Strads, del Gesus, Amatis, and the like were originally made with necks that were glued with a simple butt joint to the rib surface and later reinforced with one or more nails,

I don't think that's the right way to think of the old "nailed-on" method. The general understanding of the method these days, thanks to the "forensic" study of people like our old friend Roger Hargrave and others, is that the neck was attached to the ribs BEFORE the back and the top were made and glued on, and the nails were used instead of clamps to hold things together while drying. Think about driving in nails once the glue is dry, that would probably break the glue joint and have the opposite effect of reinforcing the joint! There are those who feel the screw c-clamp as we know it today was a rare beast in 17th-18th century italian workshops, and that we should imagine how they worked without one.

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4 hours ago, Michael Appleman said:

I don't think that's the right way to think of the old "nailed-on" method. The general understanding of the method these days, thanks to the "forensic" study of people like our old friend Roger Hargrave and others, is that the neck was attached to the ribs BEFORE the back and the top were made and glued on, and the nails were used instead of clamps to hold things together while drying. Think about driving in nails once the glue is dry, that would probably break the glue joint and have the opposite effect of reinforcing the joint! There are those who feel the screw c-clamp as we know it today was a rare beast in 17th-18th century italian workshops, and that we should imagine how they worked without one.

I'm a little puzzled by this. I have followed the same forensic studies you have, it would appear, and have drawn another conclusion. of course I agree that the neck is glued to the garland before the belly and back are made, and that's precisely how I've been doing it. But you can't well nail the neck before removing the form, and you can't remove the form while the glue is wet without knocking the neck off. perhaps you're suggesting that the neck is glued to the garland after the form is removed, which I suppose is possible, but practically i find it much easier to fit and glue the neck while the garland still has the support of the form. Drilling a pilot hole for the nail or screw, as I have always done, is necessary. I have never damaged a glue joint when putting a fastener Inna baroque neck. 

Hargrave seems to disagree about the screw clamps, as well, since such clamps are described as integral to the process laid out in his "working methods of guarneri del Gesu".

I hope this doesn't come off as personal, as I don't mean it to be. All but a couple of the instruments I've made have had traditional cremonese neck joints, and in none of these cases has installing the fastener after the glue was dry damaged the joint, hence my confusion.

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Nailing the neck while the glue is drying would be a serious PITA, even if it was jigged and whatnot. So I would have to respectfully disagree. The glue joint has to be really well fit in order to make the butt join worthwhile, and engaging in any undue shenanigans would compromise the joint security while it's drying. 

From what I remember, the cut nails are slightly wedge-shaped, which would have the effect of pushing the neck away quite a bit, even if clamped,severing the perfect union. 

But that's all my own conjecture, and I in no way know how they really did things. 

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Yes, typically square in cross section and slightly tapering. As to the joint between the neck and the garland, Hargrave once mentioned on this forum an Andrea Guarneri with an original neck. He described the fit of the neck to the ribs as rather bad, and seemed to suggest that the nail and the joint of the heel to the button was doing the work. 

In my own instruments, I chalk fit the neck to the rib surface and glue with fresh, strong hide, without the use of a clamp. Rub til it grabs and go have lunch.

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16 hours ago, JacksonMaberry said:

I'm a little puzzled by this. I have followed the same forensic studies you have, it would appear, and have drawn another conclusion. of course I agree that the neck is glued to the garland before the belly and back are made, and that's precisely how I've been doing it. But you can't well nail the neck before removing the form, and you can't remove the form while the glue is wet without knocking the neck off. perhaps you're suggesting that the neck is glued to the garland after the form is removed, which I suppose is possible, but practically i find it much easier to fit and glue the neck while the garland still has the support of the form. Drilling a pilot hole for the nail or screw, as I have always done, is necessary. I have never damaged a glue joint when putting a fastener Inna baroque neck. 

Hargrave seems to disagree about the screw clamps, as well, since such clamps are described as integral to the process laid out in his "working methods of guarneri del Gesu".

I hope this doesn't come off as personal, as I don't mean it to be. All but a couple of the instruments I've made have had traditional cremonese neck joints, and in none of these cases has installing the fastener after the glue was dry damaged the joint, hence my confusion.

Jackson, I don't mean to suggest you're going about this incorrectly. If your method works for you far be it for me to criticize it!

We do seem to have studied the same material, but retained different things from it. Your description seems to me to follow pretty much what the Hills wrote in their Stradivari book. When Roger Hargrave started publishing his articles in the 1980's, he seemed to me to be contesting some of the points the Hills had made, one of those being the glue first, nail later idea.

Here's how I understood Roger's articles: ribs finished on the mold, ribs come off, then neck gets glued and nailed to the ribs. How to hold it  in place? Either a square neck root placed on the bench and nail down from above, or he even imagined a stop-block with a spike or nail on the workbench top that corresponds with the small hole one finds inside the pegbox mortice on some original-necked cremonese violins. After that, the ribs with the neck attached are offered up to the flattened back slab, and swivelled on the locating pins to center the neck, since with this quick method it can easily wind up slightly out of alignment. Once the neck is centered, the back outline is finalized. Clamps may come in here, as we have these curious screw clamps in the Stradivari relics, and they would be useful to hold the neck block area and the end block in place while the outline is traced. By their screw pitch and shape, it has been suggested these clamps wouldn't be of much use for construction purposes.

Although I don't make baroque violins often, I have used this method and found it fast, efficient and easy. Frankly, much easier and faster than doing a modern morticed neck!

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16 hours ago, Michael Appleman said:

Jackson, I don't mean to suggest you're going about this incorrectly. If your method works for you far be it for me to criticize it!

We do seem to have studied the same material, but retained different things from it. Your description seems to me to follow pretty much what the Hills wrote in their Stradivari book. When Roger Hargrave started publishing his articles in the 1980's, he seemed to me to be contesting some of the points the Hills had made, one of those being the glue first, nail later idea.

Here's how I understood Roger's articles: ribs finished on the mold, ribs come off, then neck gets glued and nailed to the ribs. How to hold it  in place? Either a square neck root placed on the bench and nail down from above, or he even imagined a stop-block with a spike or nail on the workbench top that corresponds with the small hole one finds inside the pegbox mortice on some original-necked cremonese violins. After that, the ribs with the neck attached are offered up to the flattened back slab, and swivelled on the locating pins to center the neck, since with this quick method it can easily wind up slightly out of alignment. Once the neck is centered, the back outline is finalized. Clamps may come in here, as we have these curious screw clamps in the Stradivari relics, and they would be useful to hold the neck block area and the end block in place while the outline is traced. By their screw pitch and shape, it has been suggested these clamps wouldn't be of much use for construction purposes.

Although I don't make baroque violins often, I have used this method and found it fast, efficient and easy. Frankly, much easier and faster than doing a modern morticed neck!

Thanks for this Michael. This is my fifth time trying to write this message, due to the site going down. I appreciate your detailed response. I do all of what you describe with the exception of attaching the neck after the garland is off the form. I should reread those articles! I haven't had any trouble so I'll probably keep doing it this way, but I'll certainly try the other at least once. I agree it is very fast and easy, compared with mortising a neck!

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On 6/3/2020 at 4:52 PM, arglebargle said:

The neck joint should be strong enough with no mechanical assistance, bolts, screws, dowels and the like.

Make sure the mortise is deep enough, and every surface that should touch does, and you should be set. And good fresh hot hide glue.

Patience and a good chalk fitting will ensure a good strong joint(oh,and a sufficient amount of hot hide glue).

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