More Experiments with Dovetail joints

I've spent most of today working on a jig to cut the radius on the inside of the heel..Because of the dovetail this is very hard to do as it involves compound angles ( I can't explain how this works co's it gave me a pain in the head designing it) ..Up till now I have had to fit this part by hand with a 1/2"wood chisel and it takes quite some time to get a good fit.
This it just a prototype jig made quickly and a bit rough just to see if it works...Now I know it works I can make a posh version and get a new fine tooth bandsaw blade to get a better finish...Here is a Slideshow of the setup so far...Just click on the Pic. *EDIT Since this was first posted it has been put on my wesite and can be seen here in more detail.http://ukulele-innovation.tripod.com/

Nice idea.

To help get a smoother cut, round the back of the BS blade with a sharpening stone.

Another idea would be to use a 1" belt sander. Here in the States you can get 1/2" wide belts. This would be nice to clean up the surface after the bandsaw.

Here is a picture I found on the net to give you an idea on what I'm talking about. Obviously you would need a bigger table but you might even be able to use the same jig.

I'm sorry Ken but it's not going to fly... this joint is always 'scribed' with a chisel, a 'spline' or a bolt. I've just come back from Finland and wjilst there visited the workshop of Juha Lottenen and formaer cabinet maker who retrained in a luthier school. He has just started making ukes and uses a straight forward mortise. Whilst in his workshop, I noted his guitars have dovetail joints. Draw your own conclusions - he is still scribing in the heel but is using a mortise - not a dovetail which ends up a perfect nightmare when you undercut it!

If you wish to pursue the dovetail idea, you could simplify this by using your tools to cut the raidius on the neck then use a 'butterfly' type spline where you machine a dovetail key that fits both the neck and the neck block.

But let's face it, it's why most of us spline or bolt-on for ukes - the dovetail is for most of us an obselete form of construction. See Chuck's work and Dave Means plus the Kamaka tour at frets.com.

ANyway, best of luck with it old fella! If you manage to do this by machine you will be rewarded with a place in heaven...

Pete Howlett said:

I'm sorry Ken but it's not going to fly... this joint is always 'scribed' with a chisel, a 'spline' or a bolt. I've just come back from Finland and wjilst there visited the workshop of Juha Lottenen and formaer cabinet maker who retrained in a luthier school. He has just started making ukes and uses a straight forward mortise. Whilst in his workshop, I noted his guitars have dovetail joints. Draw your own conclusions - he is still scribing in the heel but is using a mortise - not a dovetail which ends up a perfect nightmare when you undercut it!

If you wish to pursue the dovetail idea, you could simplify this by using your tools to cut the raidius on the neck then use a 'butterfly' type spline where you machine a dovetail key that fits both the neck and the neck block.

But let's face it, it's why most of us spline or bolt-on for ukes - the dovetail is for most of us an obselete form of construction. See Chuck's work and Dave Means plus the Kamaka tour at frets.com.

Anyway, best of luck with it old fella! If you manage to do this by machine you will be rewarded with a place in heaven...

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I will succeed...This jig and tool work is the "more intresting part" of making ukes.

Ron: that won't work - it will produce a rounded edge. Chisel and patience is the deal...

Pete Howlett said:

Ron: that won't work - it will produce a rounded edge. Chisel and patience is the deal...

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You might be right.

Experimentation is half the fun, especially when you succeed.

Pete Howlett said:

Ron: that won't work - it will produce a rounded edge. Chisel and patience is the deal...

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Listen to Pete. There's a reason why dovetail-necked guitars like Martin's Standard Series and higher all cost so much more than their mortise-and-tenon neck models. They MUST be hand-fitted with a chisel, sandpaper and lots of patience. Time = money.

For what it's worth, however, all the newer Nazareth-built Martin ukes (5K, 5 Daisy, 3K, 3M, 3C) have dovetail necks (and it shows in their prices).

LameLefty said:

Listen to Pete. There's a reason why dovetail-necked guitars like Martin's Standard Series and higher all cost so much more than their mortise-and-tenon neck models. They MUST be hand-fitted with a chisel, sandpaper and lots of patience. Time = money.

For what it's worth, however, all the newer Nazareth-built Martin ukes (5K, 5 Daisy, 3K, 3M, 3C) have dovetail necks (and it shows in their prices).

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I agree that hand cut dovetails are the best. I never said they weren't.

Tim is just talking about a new idea he is working on and I offered two suggestions.

BTW, From the beginning, Martin always used a dovetail on thier ukes.

Tough Crowd

Check out Don Macrosties video on how to build a mandolin if you want to see a creative and funtional approach to this process. Don uses an old Sears shaper cutter that was made for tablesaws that is ground to match the profile of the dovetail. He has two vertical jigs that run in his tablesaw track. One holds the neck at a compound angle and the other holds the headblock. Of course, he is cutting a complete channel from front to back since the back covers the heel. It is a really impressive setup. I think he may have outlined it in American Lutherie magazine several years ago.

Ever heard of a Hoffman Dovetail Joining system? http://www.hoffmann-usa.com/htm/machines/mu2.htm I've seen this in use for all sorts of joinery and think it would be an ideal system for the instrument industry. It utilezes a dovetail key. You could make a pattern to profile the body and the heel with a router then join it using the dovetail key system.

I think these processes are overkill, but I am a bit of a voyeur when it comes to seeing how things are done and seeing if I could do it better even if it means wasting my time.

It's not the cutting of the joint that is difficult! It is the 'scribbing' in of the cheaks of the heal shoulders. As you do this you reduce the width at the neck of the dovetail. In essence you have to start with a fit that presents the neck proud; as you whittle away it seats down. Not a sensible solution for people who want to charge reasonable prices and get the job done in a timely manner.

And as a side bar: Have you seen the Martin fit and finish at this point? On the two instruments I saw - a 3K and a 5K, whoever was in charge of finishing the bodies had rounded over the edge at the neck/body joint thus leaving a gap when they were mated up.

I don't want to burst anyone's bubble but I wouldn't pay the bucks my friend did for such sub-standard work... The finish was also abyssmal - a dry sprayed satin coat that rasped when you ran your hand over it. Nope, not like the originals and not worth the money. On a sound test, my little sopranos did just as well.

Pete Howlett said:

And as a side bar: Have you seen the Martin fit and finish at this point? On the two instruments I saw - a 3K and a 5K, whoever was in charge of finishing the bodies had rounded over the edge at the neck/body joint thus leaving a gap when they were mated up.

I don't want to burst anyone's bubble but I wouldn't pay the bucks my friend did for such sub-standard work... The finish was also abyssmal - a dry sprayed satin coat that rasped when you ran your hand over it. Nope, not like the originals and not worth the money. On a sound test, my little sopranos did just as well.

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My 3C has none of the flaws you complain of. The neck heel joins the body perfectly (as it does on all my Martin dovetail-neck guitars too). Yes, the finish is satin but is not at all "raspy," merely not shiny. It's every bit as smooth as the French polish finish on my Glyph and probably a lot more durable, and certainly feels and looks like a higher-quality finish than the gloss used on my Ko'Aloha.

Pete Howlett said:

I don't want to burst anyone's bubble but I wouldn't pay the bucks my friend did for such sub-standard work... The finish was also abyssmal - a dry sprayed satin coat that rasped when you ran your hand over it. Nope, not like the originals and not worth the money. On a sound test, my little sopranos did just as well.

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Over the years Martin has allowed thier workers to build thier own instruments. The designs are for the most part identical to those that Martin sells, but without the Martin logo. I have heard stories (from reliable sources) that some of these have sold as Martin and not as worker builds. Is it possible that your friends uke is one of those instruments?

I own 2 Martin guitars. The fit and finish is right on the mark.

RonS said:

...I own 2 Martin guitars. The fit and finish is right on the mark.

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+1

I'm playing a martin right now. It's flawless inside and out.

OK so I don't know what I am talking about... fair enough. However, I know what I saw

The very subjective comments about the finish on other instruments are not strictly true - the finish on the Martin is more likely to be less durable than that on the Ko'Aloha and more so on the Glyph. That it 'looks' likely is not very scientific is it? You just don't want, like every Martin owner, to have your instrument adversely critiqued and I respect that. It's like when people sneer out our Monarchy and criticise the Queen who is the longest serving,the most experienced and probably wittiest diplomat in the world. I get very defensive when that happens.

However, they are not all good, they are not all the best .

And Ron will you stop supposing what you don't know. The instruments I saw were purchased in person from the factory by an avid and very wealthy Martin collector who has more custom instruments than you can shake a stick at! It really does get irritating when you seek to qualify your point by suggesting anothers may be not so. Stick to what you know and don't suppose that everyone else knows less than you.

petah said:

+1

I'm playing a martin right now. It's flawless inside and out.

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I doubt that remark ..I was an Engineering Inspector for many years and i've done thousands of inspection surveys on all types of products..and I have never found a flawless component or constructed assembly...They all suffer from human or other error somewhere...it's more than a visual inspection..You have to consider.. Construction methods applied, Material sources and certificates of quality, Specifications required of product, qualifications of work force, storage of consumables (Glue and Laquer in ukes) are they within their use by date? etc, batch numbers required..Letters of conformaty, test pieces of glued samples (are the results of testing in par with manufactures claims?)...then we get down to measurment, are the dimensions compatable with specification, we have to check first for sqareness and linement (how far off centre is the bridge to the the edge's of the lower bout ? etc..I could go on for ages on all this stuff...But this is just basic QA..You should see what we had to go thro' to produce Nuclear Submarines.

Pete Howlett said:

The very subjective comments about the finish on other instruments are not strictly true - the finish on the Martin is more likely to be less durable than that on the Ko'Aloha and more so on the Glyph. That it 'looks' likely is not very scientific is it?

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I used to design life support equipment for the U.S. manned space program. If you want to get really scientific instead of tossing around incorrect adjectives (e.g., "raspy"), by all means do so.

You just don't want, like every Martin owner, to have your instrument adversely critiqued and I respect that.

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You don't know me and you're projecting your emotional impressions on what I actually wrote. Criticize what you like objectively: for instance, the end of the fretboard isn't chamfered like it is on my Glyph. To some people, a completely non-functional aesthetic thing like that is a very big deal. To others, it doesn't matter much.

However, Dave took 22 months from the time of my order until delivery for it. My 3C took about three days from the time I ordered it until FedEx delivered it to my office. Even setting that aside, it was built on the line like nearly all Martin instruments and it was probably done from laser-etching the neck block to final inspection after stringing in less than 3 months, along with the 35 others Martin built in 2008.

Now, having said all that, this quality of workmanship is equal to that of my Glyph. Of course, the design aesthetic is much simpler than that of my Glyph too. But on the flip side, my 000-42 sunburst was absolutely and utterly perfect at delivery and has woods that have literally stopped Martin insiders in their tracks when looking at it (someone clearly picked out some special stuff from the Sawmill the day they started it). However, I can say this in the same breath as saying that I really hate that my HD-28V has a lifting bridge and that the saddle is Micarta (which was standard before 2004). But on the positive side, the bridge is being reglued under warranty, and while it's being done I am having the luthier replace the nut and saddle with bone.

In short, I'm quite capable of discussing an instrument's shortcomings as well as its positives. And in this case, with regard to my 3C, the inlays are perfect, the finish is smooth and durable, the woodworking is CNC-perfect, the tuners work well, and, oh by the way and back to the the topic at hand, the dovetail neck is fitted perfectly (and unlike my guitars, I'm not likely to need to use the lifetime warranty for a neck reset in the next 10 - 20 years).

Pete Howlett said:

I don't want to burst anyone's bubble but I wouldn't pay the bucks my friend did for such sub-standard work... The finish was also abyssmal - a dry sprayed satin coat that rasped when you ran your hand over it. Nope, not like the originals and not worth the money. On a sound test, my little sopranos did just as well.

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Pete Howlett said:

And Ron will you stop supposing what you don't know. The instruments I saw were purchased in person from the factory by an avid and very wealthy Martin collector who has more custom instruments than you can shake a stick at! It really does get irritating when you seek to qualify your point by suggesting anothers may be not so. Stick to what you know and don't suppose that everyone else knows less than you.

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You don't need to get your panties all tied up in a knot.

You didn't qualify in your original remark that the person was an experienced collector. You just remarked that the work was sub-standard.

Not seeing the instrument, I asked a simple question if something was possible.

heh... You guys take to stuff like it's a blasphemous comment. This Martin is a great instrument. To me, my father a player of over 40 years, his friends in the industry etc etc etc... It is as flawless as flawless can be. Much better than any other guitar I have played. If you guys want to get technical in every post This place will go to ...

Well maybe Martin has upped their game recently - on a custom I saw the 1st fret inlay was off centre, badly filled and that was just the start...

There is good and bad to come out of all shops. I freak out if I don't get my mitres perfect and you only know that is going to happen when you scrape back. One spec of dust in the glue and that joint line is the first thing you see.

It also amazes me how loyal Martin owners are. Good on you guys. Someone has to keep buying their stuff:nana: However a visit to my mate who is a warranty man is enough to convince me that they don't always get it right.

I would swear you are trolling for an argument.

Pete Howlett said:

Well maybe Martin has upped their game recently

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Nope
I once had a '62 D-28, its as well built as my '08 Aura

troll said:

It also amazes me how loyal Martin owners are.

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I own 9 acoustics guitars only 2 are Martins. (and 5 electric guitars)

Perfect Pete said:

However a visit to my mate who is a warranty man is enough to convince me that they don't always get it right.

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Of course your instruments are perfect every time