Sy8 - 8 Strings 'n Things

[curtisa]

Righto, while I'm waiting for the finish on SY6 to cure fully I figure I can get cracking on Number 4. I'm going with some more local species again, plus I scored a really nice giant slab of Tasmanian Myrtle burl at half price, probably enough for 4 bookmatched tops if I tread carefully. It'll be an 8 string but tuned low to high A-D-G-C-F-A-D-G, effectively a standard 7 string down a full step with an extra string on the top instead of the low F#.

Target specs:

Body - Victorian Ash with figured Tasmanian Myrtle carved top

Neck - 5pc Celery Top pine/Tasmanian Myrtle/Vic Ash with Jarrah fingerboard

Scale length - 26.5"

Radius - 16"

Trussrod - Allparts

Tuners - Hipshot Grip Lock

Nut - Graphtech black Tusq

Frets - Jumbo stainless steel

Pickups - EMG 808X neck, 808 bridge

Bridge - Hipshot 8 string fixed

Electronics - 1x vol, 1 x 3-way toggle

That myrtle slab:

Got wood?:

[Donnb]

I like the woods you have chosen. I might have to look around for some Vic Ash myself.

[curtisa]

I like the woods you have chosen. I might have to look around for some Vic Ash myself.

Thanks. Down here Vic ash (aka Tasmanian oak) is as common as muck, but I wanted to give it a go as I'd heard mention that a nice clear piece makes a good substitute for mahogany. Can be a bit heavy, although the piece I'm using isn't too bad. Haven't weighed it, but it feels lighter than the Queensland maple I used on SY6.

Trussrod channel routed. I've used a couple of countersunk screws in the waste-side of the blank to hold the neck in place while running the router up the middle. While lining up the guide for the router I had an idea for a new jig that I might explore in the near future. A kind of multi-function thing that would enable me to hold the neck blank to do various things like route the truss rod channel, put the volute on the back of the headstock, route the nut shelf etc...Anyhoo, back on topic:

Neck taper and headstock trimmed to size:

Vic ash body routed to shape, and control and battery cavities added. I'm so glad I went to the trouble of making decent templates out of plexiglass when doing SY6. What took me 3 or 4 days to get this far now takes a quarter of the time:

[demonx]

That myrtle looks fabulous...

Tasmania has so many beautiful timbers, you're very lucky to live there.

[curtisa]

Ta. That myrtle was definitely a lucky find. I picked it up at a country town craft store where the owner was getting rid of all his speciality timber slabs to make way for a coffee shop he was setting up. Everything was half price and I couldn't resist. Also grabbed a piece of straight-grained Tas blackwood that will probably do two necks for $15. He had some blackheart sassafrass boards too (which I'd like to try out one day), but they were a bit too twisted and warped so I gave them a miss.

[ScottR]

That myrtle looks fabulous...

+1

This should be fun.

SR

[curtisa]

1 piece Vic ash, 1 piece Tas myrtle, 1 metric f**k-tonne of clamps (and there's probably still room for a few more in there. Might need to go shopping again...):

[curtisa]

Out of the clamps:

[curtisa]

Edges of myrtle top trimmed down.

As a side note, I think I may have stumbled upon a reliable way of routing body shapes with minimal risk of tearout. The trick is to use two router bits - one with the bearing at the top of the bit and one with the bearing at the bottom. Attach your template to the piece to be routed and use either bit in the table router and route as you would normally, but don't do the cutaways and horns.

The danger zones in my experience is the tips of the horns where the edges suddenly change from going parallel the grain to perpendicular to the grain, or inside the cutaways where the same thing occurs. Couple this with the low amount of mass at these points and it's easy to see why the router has a tendancy to grab and take chunks out. When you get to these points consider the rotational direction the bit is moving in relative to the grain. At these tight points you want the bit to remove timber in a direction that doesn't cause the grain to lift away from the work piece. The bit should "scoop and compress" the grain, rather than "shear and lift". Another analogy is to imagine running your fingernail along a piece of velvet - in one direction it will smooth the velvet down and offer little resistance, in the opposite it will cause all the velvet fibres to stand up and feel rough to the touch. What this means is that you'll have to go halfway around each of the curves with the template on top using the bit with the bearing on top, and to do the other half of each curve with the workpiece flipped over so that the template is underneath and use the bit with the bearing at the bottom. It also means that it's possible to do an entire body without having to resort to (IMO) a risky climbing cut.

Maybe this is old news to some people here, but it works pretty well for me so I though I'd share. I used the above method for trimming the myrtle top down to the body profile here and had no trouble whatsoever, even with all that crazy wavy grain:

[Levi79]

This is going to come out so nice!

[curtisa]

A fretboard gets its slots:

And a neck gets its fretboard:

[curtisa]

Out of the clamps and fretboard trimmed flush. Sorry about the crap pics. Mid-winter afternoon light makes for lousy photos:

[curtisa]

Time to get the wheels rolling again. Little bit more progress on the neck this weekend. Thinning down the headstock and adding the nut shelf on the router sled:

Experimenting with some ideas for position markers. The centre pin is red myrtle and the outer ring is maple. A little bit off-centre in the trial, but I reckon if I use a brad-point bit instead of a twist drill to hollow out the maple slug it will come out looking nice and tidy.

Stu, if you're reading this, thanks so much for the explaination of your method for doing these concentric plug thingies!:

[Levi79]

Looking incredible man! Keep up the good work!

Edited September 2, 2012 by Levi79

[Shelvock]

Really liking the idea if those markers, really looking nice

[curtisa]

Thanks guys.

Used a bit of quiet-time at work to catch up on a couple of things. Jack socket:

And string ferrules. Used RAD's method for drilling the ferrules and bridge holes this time round (detailed here - Thanks RAD!). Last time I drilled the holes using the "attach bridge/drill halfway/flip bridge to back/drill halfway" method and the ferrules still ended up wandering a bit. This time the result was damn-near perfect. Even used the Stewmac tuner counterbore to recess the ferrules. Worked like a charm:

Edited September 12, 2012 by curtisa

[Prostheta]

Edges of myrtle top trimmed down.

As a side note, I think I may have stumbled upon a reliable way of routing body shapes with minimal risk of tearout. The trick is to use two router bits - one with the bearing at the top of the bit and one with the bearing at the bottom. Attach your template to the piece to be routed and use either bit in the table router and route as you would normally, but don't do the cutaways and horns.

The danger zones in my experience is the tips of the horns where the edges suddenly change from going parallel the grain to perpendicular to the grain, or inside the cutaways where the same thing occurs. Couple this with the low amount of mass at these points and it's easy to see why the router has a tendancy to grab and take chunks out. When you get to these points consider the rotational direction the bit is moving in relative to the grain. At these tight points you want the bit to remove timber in a direction that doesn't cause the grain to lift away from the work piece. The bit should "scoop and compress" the grain, rather than "shear and lift". Another analogy is to imagine running your fingernail along a piece of velvet - in one direction it will smooth the velvet down and offer little resistance, in the opposite it will cause all the velvet fibres to stand up and feel rough to the touch. What this means is that you'll have to go halfway around each of the curves with the template on top using the bit with the bearing on top, and to do the other half of each curve with the workpiece flipped over so that the template is underneath and use the bit with the bearing at the bottom. It also means that it's possible to do an entire body without having to resort to (IMO) a risky climbing cut.

Agreed for the most part. The feed rate and cutter speed play a role also. The overhead pin router I have been using recently is insane fast and you can pretty much do an entire body without climb cutting. I was taken aback how clean it was. The reduced flex also meant no burning allowing slower controlled work.

[curtisa]

I guess time will tell if my method will continue to work. So far this is the only body-routing job I've been able to test it with. My limited experience suggests that it may have cured "router munch" in the parts of the body I tended to have trouble with. Then again I may have just simply gotten lucky this time?

Of course I don't mind...ahem..."practising" on a few more builds

Position markers drilled:

Just waiting for the glue to dry on these before I get going on the inlay:

[Prostheta]

When moving the workpiece into the cutter i hit it moving to "feather in" the cut and so the cutter doesn't take the workpiece into a climb cut. It's difficult to describe but you know when the router is out to git ya.

[curtisa]

Position markers epoxied in:

Trimming. I've used a thin piece of aluminium sheeting to protect the fretboard while I'm cutting off the excess. The saw is one of those crappy flexi-blade things you can usually find advertised as "razor sharp" (yeah, right!) in a $2 shop:

Sanded flush. Not quite as clean-looking as I'd hoped, but I think the idea has got legs, and I'd certainly give it another go on future builds:

[Anthony]

They look like miniature Combos snacks lol.

[curtisa]

Sadly not anywhere near as tasty...

[curtisa]

Wee bit more progress this weekend. Spent most of my time toying with a new neck clamping idea for securing the neck while performing various shaping and routing tasks. Came up with this Meccano-looking thing. Needs a couple of tweaks still, but seems to do the trick. There are two rubber stoppers on each rail that grip on to the sides of the neck when the screws are tightened. I gave it a test run while doing the tapering of the neck with the router sled and it held everything nice and tight without any slipping. Next task is to add adjustable height screws so that I can raise and lower one end for tapering jobs without resorting to sticking offcuts of aluminium at one end to get the base to tilt, as I did here (just visible at the bottom-left):

Volute. Nothing fancy here. Celery Top Pine has a wonderful spicy aroma while being worked though:

[curtisa]

Skipped ahead a bit without taking any pictures, sorry!

Neck is carved. Frets knocked in and polished. Recently purchased a 1 ton arbor press, so this may be the last time I use the hammer. Also whipped up a fret bender out of offcuts of perspex and whatever else I had lying around in my parts drawers:

Test fit. The fretboard has had a few coats of oil which explains why the colour has deepened so much compared to the previous shots. Body carve is about 90% done. Still need to add a headplate - I have a couple of myrtle offcuts leftover from the body which I've set aside.

[curtisa]

Body carve done. Decided to try something a little different this time round and deliberately carved through to the back all the way around the edges giving it a nearly-sorta bound look. Might work, might not. But willing to try:

Headplate in matching Tas myrtle getting glued: