Mary's 7-String

[Akula]

I've got a mate named Mary.

 

Last year when I fell off the wagon and started habitually building guitars again, my mate Mary expressed a bit of interest in getting an instrument made up to his specs, and finally I've found the time to make good on my word and build the thing.

 

Mary's design brief was this: take inspiration from the Soloist, must have a hard-tail bridge, and sprout enough strings and scale-length-inches to afford the ridiculously low tunings often played by the coolest kids on the block. I agreed most wholesome.

 

Timber arrived today. Slab of mahog' for the wings, a big bit of maple for the middle bit, and an ebony fretboard. 

 

I jumped right into it, sparing only moments to make a cup of coffee before marking out the scarf joint. I know my way around a few graphic design and CAD softwares, but I can't seem to put saw to timber without a paper plan on the bench. Marked out the lines with a knife, then my tenon saw made the cut.

 

Lots of planer-love needed to take care of that scarf joint. Straight off the saw it was rough, slightly skewed, and nowhere near true, so I got into it with planes, planers, and a ceramic tile wrapped in sandpaper until it screamed flat.

 

Ended up with a 45mm thick headstock and a 45mm thick neck.

 

On previous builds I've removed material with a jigsaw (which went terribly - blade bending is a thing!) or a router, the latter of which is great at turning timber to dust while wearing out expensive bits. This time, I opted for removing the under-neck and over-headstock material with a hand saw. Note to self: buy a band saw! Cutting through 400mm of 70mm maple sucks.

 

Now I've got something resembling the cross-section of a guitar. Needless to say I'll need to thickness the neck properly with a router on rails, and remove about 5 or 10 mil of material from the back of the headstock after properly planning the volute. 

 

Glueing up the scarf joint was a pain this time round. Last few builds, I used the salt-trick, but this time the thing just wouldn't stop slipping. I had a read of @Muzz's Marauder build, and tried his ingenious caul method - but, alas, major slippage. Now, if I'm struggling with an idea poached from someone who's built such high-quality instruments, I guess it's just not my day; I gave up and drilled a hole either side of where the nut will eventually be, applied some new glue, and located the pieces with two drill bits before clamping up. 

 

Last job of the day was to copy the paper plans and cut them out with a scalpel, ready to be glued onto MDF tomorrow and turned into a template. I had hoped to get the wings glued on at the same time as the scarf joint, but the timber turned up from the mill with a few imperfections that need sanding out. Besides, when you're struggling to perform a scarf joint on a sunny day, it begets the feeling that you should maybe sleep on it.

[Akula]

Had a go at the truss rod routing today. I've built the standard jig involving a U-shaped channel within which the router rides and has no play, and the neck sits inside bound at the sides by bolts, therefore giving an adjustable jig usable on theoretically any neck.

 

This jig design has ran me well for a few build so far, and today it was just perfect. Except for something unrelated to the jig - router bit slipped in the collet. 

 

Now that's just plain scary. The big slipped into about 4mm more depth than I'd like out of the slot, and the vibrations tore up the other side of the slot just a little. Upon inspection, I reckon I had a rusty bit shaft, and that rust must've blown away under pressure and the bit got loose - but, I'm open to suggestions here, has anyone else a reason why router bits suddenly cut deeper than they're supposed to?

 

Onto the solution. I cut a piece of maple to size, glued it into the bottom of the slot, and then cut it flush. The depth of the mistake should still leave a good bit of timber between the truss rod and the neck thickness, but I didn't want to have any truss rod rattle, so I plugged it.

 

Re-routed with a new 6mm bit fresh from the hardware store, and job's a good'un.

 

Ideally, I had wanted to get the body wings glued to the neck today, but I ran into an issue when I realised I'd gotten my blanks machined to 70mm width, whereas the maximum width of the neck only reaches 68mm. To avoid some weird-looking joints where the neck appears wider at the heel, I decided to take the width down a notch before gluing, and at that point of the evening I'd run out of time to properly true-and-glue the faces.

Next thing after gluing up will be to rough cut then route the body, neck, and headstock, so I figured I'd make some headway and cut the templates out of MDF.

[Bizman62]

2 hours ago, Akula said:

I reckon I had a rusty bit shaft, and that rust must've blown away under pressure and the bit got loose - but, I'm open to suggestions here, has anyone else a reason why router bits suddenly cut deeper than they're supposed to?

I've had that happen once and the only culprit I could find was that apparently I just hadn't tightened the bit properly which seems a bit odd since I'm a bit overconcerning with power tools. Although the rust theory would have made me feel better... But there's no rust in the tools of the communal workshop. They're dull and poorly maintained but not rusty. Another option that came into my mind is that there might have been some wood dust clogged in the slots of the collet. That would explain both your and mine cases.

[ScottR]

3 hours ago, Bizman62 said:

Another option that came into my mind is that there might have been some wood dust clogged in the slots of the collet.

I find that often. I tighten the collet till it's tight......or so it seems. If I power through that tight spot, I find there are several turns left till it's tight. If I take the collet off and clean it up with compressed air, that doesn't happen on the next bit.

SR

[Andyjr1515]

14 hours ago, Bizman62 said:

Another option that came into my mind is that there might have been some wood dust clogged in the slots of the collet. That would explain both your and mine cases.

Yes, I agree with @ScottR and @Bizman62.  The collet slots can fill with very fine dust.  It will tighten real tight, with the dust being compressed.  However, the heat of the bit then can burn the dust and you are left with a gap...and a loose bit.

I keep a thin strip cut from thin vac-pac packaging to just clear the slots before I put the bit in.  I started doing this after wrecking a piece with a loose bit...

Some nice plane and hand saw work going on over there, @Akula

[Akula]

I agree with all three of you - I think it was dust in the collet. I always give the router a blast of compressed air when changing bits, but I also realised that a 6mm bit in a 1/4-inch collet is different to, say, a 1/2" bit in a 1/4" collet. Look at me, getting all imperial in a metric world. Point I'm making is, with a bit wider than the shank, I never have this problem, but when the bit diameter is close to or smaller than the shank size, my bit suddenly wanders south and nearly wrecks a good bit of maple. I believe that had something to do with it.

Anyways, the bit was also rusty. Last time I put a lackluster bit into a router.

 

 

Got called into work today at last minute, so all I had time to do was glue up the headstock wings. Managed to get the entire footprint out of the same square end of the board. Hope that'll make thicknessing easier later on.

 

Because of the board efficiency, I had angled edges to clamp, so I whacked a tiny angle bracket into what will become waste material underneath the headstock, to stop the pieces sliding under clamp pressure.

[Bizman62]

1 hour ago, Akula said:

but I also realised that a 6mm bit in a 1/4-inch collet

Ouch! You can't get it tight no matter what! That's over third of a millimetre too thin! Or the collet is almost 6% too large!

The angle bracket is a clever little outside-the-box idea!

[Akula]

15 hours ago, Bizman62 said:

Ouch! You can't get it tight no matter what! That's over third of a millimetre too thin! Or the collet is almost 6% too large!

The angle bracket is a clever little outside-the-box idea!

Ah, let me clarify - I meant, the Cutting width of the bit is 6mm, the shank is still 1/4" in a 1/4" collet. My thinking was, since the flutes are inside the diameter of the shank, the more dust is prone to shooting up into the collet instead of being vacced out of the way. Indeed, a 6mm shank in a 1/4" collet would be bad!

 

I guess the angle bracket is a bit unorthodox, but it got the job done!

[Bizman62]

Whew!

Your theory may be right. Then again wouldn't a wider-than-the-shank bit swirl the dust even more around the collet? Hard to tell, guess no-one has ever studied the aerodynamics of a router!

[nakedzen]

Def stealing that bracket idea for future use. Following with interest. Where did you get the maple, I'm having trouble finding long enough blanks for neckthrough?

[Akula]

3 hours ago, nakedzen said:

Def stealing that bracket idea for future use. Following with interest. Where did you get the maple, I'm having trouble finding long enough blanks for neckthrough?

Whereabouts are you located? I use a local timber company in Sydney, but I've found good timber on eBay before - usually a search for the kind of timber you're after instead of "guitar blank" will help, as I find most boards marketed towards guitar building seem to be inflated price. Searching for and then calling timber supply companies is a good idea too, the old art of pickup up the phone is useful as many places will point you in the right direction if they don't have stock themselves.

Hope you find a good supplier! If you're in Australia, shoot me a message and I'll point you to a few specific dealers.

[nakedzen]

Nah I'm in Finland. All what local suppliers have here are birch and pine.

[Bizman62]

Hakalan Puutukku, Lahti.

[Drak]

4 hours ago, Bizman62 said:

Hakalan Puutukku, Lahti.

I had to choose the 'Summary in English'.

I feel so ignorantly American sometimes...

[Bizman62]

I still love you.

[nakedzen]

14 hours ago, Bizman62 said:

Hakalan Puutukku, Lahti.

Yeah I know them and tried emailing them in the past, never got a reply. Phone only?

[Bizman62]

If they have an e-mail then that should work. Did you use their actual e-mail or the form? In either case, did you check your Junk mail folder? Also, seeing that they have an outlook.com address, I wonder if they looked into their Junk mail. If you mailed directly to them and your address contains the word 'naked' it may well go to junk.

[nakedzen]

3 minutes ago, Bizman62 said:

If they have an e-mail then that should work. Did you use their actual e-mail or the form? In either case, did you check your Junk mail folder? Also, seeing that they have an outlook.com address, I wonder if they looked into their Junk mail. If you mailed directly to them and your address contains the word 'naked' it may well go to junk.

Nah it was from my personal email. It was ages ago and found other suppliers which I've been using, so I might try them again.

Sorry for the offtopic.

Edited August 16, 2021 by nakedzen

[Akula]

Glued up the neck blank the other day. I had to trim the maple to 68mm wide using a straight edge and a bearing bit, as that's the maximum width of the neck taper, then of course I did the neck taper with the same method. There was a lot of hand plane and sandpaper action to get the surfaces glue-up ready, then a slather of glue and some clamps.

 

Got up this morning all bright-eyed and bushy-tailed ready for some body shaping. Rough cutting will be done with my jigsaw, which is of terrible brand and quality, so I marked out the template on both sides and drilled a few relief holes in tight areas. My jigsaw shoe never sits straight (not even only in the vertical plane - yeah, think about that one!), so I was real careful not to make any incursions into the final shape of the guitar. When you've got a crap jigsaw, you can never err too far on the side of caution. Still, I got to within 3mm of the shape on the best side of it, and within 8mm on the worst.

 

Got the template clamped down in three places at all times, and hit it with a 10mm cut depth bearing bit.

 

I climb-cut far more than I should professionally let on. But, after going "backwards" around horns and tight curves, I feel like I can make a "safer" cut in terms of tear-out, and clean up afterwards with a quick "forwards" pass. I did five passes altogether.

 

I got some scorch marks, and some bearing bite, despite using two bearings on the same bit. All up, I'm fairly happy with the routing today, I didn't blow anything out and I removed all the material that isn't guitar down to a fraction of a mil. Nothing a good bit of sanding can't tidy up. I did the last pass with a bottom-bearing bit, with the body flipped over.

 

Did the headstock too, while I was in the mood, and called it a day.

[Bizman62]

Does your jigsaw bend on one (always the same) direction when sawing thick materials? Mine does, and knowing which way it bends helps sawing close to the line if you can keep the right direction - the bottom side will then be a bit larger which is easy to fix with a router.

[Akula]

6 hours ago, Bizman62 said:

Does your jigsaw bend on one (always the same) direction when sawing thick materials? Mine does, and knowing which way it bends helps sawing close to the line if you can keep the right direction - the bottom side will then be a bit larger which is easy to fix with a router.

Yep, it does. For added fun, my blade doesn't point "forward" in relation to the shoe or the jigsaw body, it's off at about a 20' angle. So I kinda have to hold the jigsaw a little bit off-centre, and watch where the blade's going instead of the shoe. 

I really need a new jigsaw!

[Bizman62]

6 hours ago, Akula said:

my blade doesn't point "forward" in relation to the shoe or the jigsaw body, it's off at about a 20' angle. So I kinda have to hold the jigsaw a little bit off-centre, and watch where the blade's going instead of the shoe. 

My Black&Decker has been doing the same since the very start. One reason for that may be how the blades are made. Some time ago I read about band saw blades tending to do similar things and aside proper adjusting the quality of the blade is important. It appeared that some blades are just die cut out of sheet metal with burr on the other side all the way. Remembering that I took a look at my jig saw blades. The old ones I had were just like that, no sharpening marks at all and the teeth splayed at one go so that the entire width of the blade was bumpy! The new ones were made differently (despite being cheap Lidl stuff): The blades were ground on the outside and the teeth were ground into the edge similarly to the shape of the Swiss army knife - no splaying, only ground grooves alternating from side to side.

All that said I can't remember if the new blades do any better job than the old ones but they at least are machined instead of die cut.

[Akula]

9 hours ago, Bizman62 said:

My Black&Decker has been doing the same since the very start. One reason for that may be how the blades are made. Some time ago I read about band saw blades tending to do similar things and aside proper adjusting the quality of the blade is important. It appeared that some blades are just die cut out of sheet metal with burr on the other side all the way. Remembering that I took a look at my jig saw blades. The old ones I had were just like that, no sharpening marks at all and the teeth splayed at one go so that the entire width of the blade was bumpy! The new ones were made differently (despite being cheap Lidl stuff): The blades were ground on the outside and the teeth were ground into the edge similarly to the shape of the Swiss army knife - no splaying, only ground grooves alternating from side to side.

All that said I can't remember if the new blades do any better job than the old ones but they at least are machined instead of die cut.

Thats a very interesting thought! I shall have to check tomorrow, but I'm sure this saw has always done the push at an angle no matter which blade I've used. The extent to which it's falling foul, however may differ depending on the blade, hence I'll check on some pine in an hour where power tool noise is looked upon favourably.

 

No progress today - I had planned to thickness the neck with my router sled jig, but I found the reach of the bit wouldn't quite reach the dimensions needed. So now I'm in two minds: I can build a new sled, or just build a bespoke set of "rails" to run my router across, bolted or clamped to the workbench. I'm leaning towards the latter. 

Had a chat with Mary concerning neck dimensions today, and it looks like we're going for a 20mm at gret 3 to 21.5mm at fret 12 sort of profile, which means I need to bring my 7mm ebony fretboard down to 5mm. That's definitely a router router job.

At what point does the fretboard become too thin? 

Had I thought about it three days ago, I could've routed a truss rod channel into the underside of the fretboard as well as the neck, but as it sits the thinnest I can carve the maple to is 15mm. 

There will also be a modest top carve on this build, which my crafty hands are saying "angle grind it!" while my logic is thinking of investing in some nice gouges - even though they are pricey they may serve well in the future.

Finish options are on the table too. The mahogany will look great under an oil finish, it's just a matter of staining the maple to somewhat match the colour to within reason. 

[Bizman62]

13 minutes ago, Akula said:

At what point does the fretboard become too thin? 

I've seen necks with a >1 mm veneer as a fretboard, the frets been sawn to the neck. Obviously any truss rod has been installed from the palm side of the neck - if there's been any at all!

Seriously though, as ebony is very hard some 5 mm should suffice. The rosewood fretboard on my Am Std Strat neck isn't thicker than that but the truss rod has been installed from the bottom side so there's some meat in the middle.

[Akula]

I went for a 5mm thickness on the fretboard, in the end. Took me a damn age to get the router marks out - ebony is hard!

 

Then I did a proper thickness on the neck with the router. Since the body and horns would be the greatest obstacle hitting the router base, I used some stock of the exact same thickness as rails - the offcuts I jigsawed off the body blank. Worked a treat, and the neck is now at 15mm thickness. Plus the fretboard, and minus maybe a mil or half during shaping, and that brings us to 19(+-0.5)mm. I also did some dough step-routing on the heel at this point, to save grinder dust later.

 

Then I went in with the aforementioned grinder with a flap disc, and roughed in the top carve. Being influenced by th Soloist shape, we didn't want to take too much material away, so I took inspiration from some Ibanez photos and went lightly. I think the deepest this carve gets is about 5mm. There will be much more fine tuning once our lockdown is over and the client is legally allowed to visit my workshop. 

 

Next jobs will be to mark and cut the fret slots, then trim the fretboard to size and glue it down.