Compact short scale build

[3below]

Inspired by the work of others ('standing on the shoulders of giants', I blame Andyjr1515 in particular) the hewing of wood has started. The bass is inspired by Rob Allen basses, an Aria PE Les Paul type bass and my trusty Gibson SG bass.

Body: Chambered mahogany - the 43mm x 7" x 40" plank is air dried 30yrs plus, ex snooker table £5 - I bought more

Body top slab: oak. 9 - 12mm undecided on thickness yet.

Neck : white oak and mahogany stringers. Gibson SG bass profile plus a few mm depth, this will be a 'baseball bat'. Two per side small tuners, headstock string angle same as Fender type headstock h. (The oak was from a floor I removed about 25 years ago and the mahogany was also some salvage from years ago).

Fingerboard: Ebony, fretless. This has planed down to 10mm.

Bridge: Ebony, acoustic bass type, Acetal (aka Delrin) saddle.

Pickup:: initially piezo underbridge (£6 I think). I intend to design the body chambering so that later retro fit of J tyope pickups is a possibilty if the piezo route is not to my taste.

Pre-amp: I thought of design and build my own (I have a Physics / Engineering background) but then had the obvious inspiration. I have some pre-amps. I could also dis-assemble a Behringer acoustic-amp and fit it internally if so desired. To be explored.

Watching the [url="http://basschat.co.uk/topic/289254-jack-bruce-ish-eb3-sg-bass/page__fromsearch__1"][b]Andyjr1515 EB3 build[/b][/url] develop I appreciate the advantages of a through neck, my next build will go down that route. This current one will be bolt on. The aim is to have a 30.5" scale bass, bridge as far back as possible, making the bass as compact as possible. My diagrams / plans /templates suggest I will get the equivalent of a 17 fret neck. This should prevent neck dive. The compactness suits me fine as I am somewhat vertically challenged.

Body slab and neck stringers:




Body outline and neck - the end of the truss rod is where the fingerboard will end, headstock to be as compact as possible. It is not a left hander, I just took the picture that way, no idea why



Thoughts and advice most welcome, particularly slot routing 3mm channel for bridge saddle. So far my attempts (with jig) on scarp have been less than 100%.

Edited August 19, 2016 by 3below

[Bastav]

Nice, will be watching!

[Andyjr1515]

Oooooo - flattery gets you everywhere. Definitely will be watching this one!

[3below]

Some progress, however the moral of the story must be do not do stuff that requires thought when you are ill. Have been wiped out with some stomach thing since Saturday. On mend slowly.

Mistake number one, body timber jointed. I had faced one edge and had planned to flip one piece over to maintain the grain direction. Grain runs same way on the jointed slab. An unintentional chamfer was the result since I forgot to flip the piece over. Fixed by a quick pass through the Wadkin 24" planer in a local joinery shop (free, would not even accept beer tokens). Second mistake results from this. Pleased that I now have the back flat and true I forgot to ask for the front to go through the planer. Needless to say it was domed. Rediscovered the pleasure of using a jack plane which quickly sorted it. I would like a planer that takes 20" timber, not cheap though.




Mistake number three emerged, slight glue starvation. I think I will enlarge the groove with tenon saw and infill with a sliver of the same mahogany. Should be invisible.




Body jig sawn to shape, I am using my toy jig saw (I have an industrial Italian machine awaiting commissioning aka swmbo ceases using workshop as storage). 40mm mahogany cuts like butter, 9mm 30 year old oak is a different matter. I think of one of my favourite Dr Feelgood songs - I'm a hog for you baby.



Mistakes four and five next. Bad day with the router despite template. Depth stop slipped and the body has got a little thin (6-7mm) in the upper bout. Also managed to get two 'runaway' cuts in same place, I think this is tied up with router height locking slipping.. Plan is to glue some 3mm veneer in the thin section. To make matters worse the collets worked loose during routing which did not help. Next time, smaller router cut length, double collet locks and 12mm or even 15mm template. I also need to investigate the depth locks on my router, I think they are slipping. The divot in the lower bout is not my doing, the ex snooker table planks have a locking mechanism (like flat pack furniture).





Weird dried resin inside the plank. You would be miffed if you planed your timber down and this appeared on an external surface.



Luckily the worst blunders are internal, I just know I they are there. No progress on neck at all, I decided do 'simple' stuff since I would certainly fubar anything that needs precision at the moment.



The large 'lands' are intentional. If I decide piezo pickup is not for me, the lands are positioned and sized for jazz bass pickups. Oak top just visible in background. Body with top about 4lb at moment.

Edited August 25, 2016 by 3below

[Andyjr1515]

Ref the overcut of the router, as long as there's nothing going there, 6-7mm is plenty thick enough.

Looking really good

[3below]

Nothing going in the overcut area, the only 'control' will be the jack socket . I share your concern about edge routing the body, it would be b* to get a tearout at this stage. I have either 2" cut 1/2" shank template bit i.e. all in one go or 1" cut 1/4" shank i.e. two successive passes. Andy, what tactic do you use? Apart from the hardness of the oak (it just ignores 80 grit paper) hand tools are tempting. First guitar built aged 13, from elm coffin boards and coffin making scraps (aka free), all done with hand tools, seems a lifetime ago.

Edited August 25, 2016 by 3below

[Andyjr1515]

[quote name='3below' timestamp='1472153549' post='3118984']
Nothing going in the overcut area, the only 'control' will be the jack socket . I share your concern about edge routing the body, it would be b* to get a tearout at this stage. I have either 2" cut 1/2" shank template bit i.e. all in one go or 1" cut 1/4" shank i.e. two successive passes. Andy, what tactic do you use? Apart from the hardness of the oak (it just ignores 80 grit paper) hand tools are tempting. First guitar built aged 13, from elm coffin boards and coffin making scraps (aka free), all done with hand tools, seems a lifetime ago.
[/quote]
Assuming they are both bearing trimmer bits with the same cutting diameter, I would personally go with the shorter one until I'd done a few successful bodies. A 2" bit, if it digs in a bit too hard, can kick like a mule with no chance of holding it. Same can happen with a shorter bit but at least it gives you a fighting chance.

However, presumably you would need a bottom bearing bit to do the second half?

If you don't, I'm not sure how you will be able to do it, in which case, maybe hand tools are the safest, if not the quickest ....

[3below]

Ron Kirn describes using a top bearing trimmer bit with a template. Take the first cut with template. Lower the bit and then use the newly cut body as the template for second lower cut. Seems plausible to me. Could take quite small passes e.g. 1/2 inch at a time. Am I missing something obvious.

Edited August 25, 2016 by 3below

[Norris]

The key is not removing too much material in one pass. If you need to use the full depth of the cutter to get the bearing on the template, shave a mm or two off with each pass until you work your way to it. Don't try to chew it all out in one go.

[scojack]

+1 (Think weve all done this, i certainly have).
I do 3mm at a time, you should hardly get any resistance,that way you can feel straight away when something goes wrong .
It's good to get into the habit of checking the bit and depth stop are tight every time you pick the router up, works for me but then i'm getting doddery.

[Andyjr1515]

[quote name='3below' timestamp='1472158451' post='3119049']
Ron Kirn describes using a top bearing trimmer bit with a template. Take the first cut with template. Lower the bit and then use the newly cut body as the template for second lower cut. Seems plausible to me. Could take quite small passes e.g. 1/2 inch at a time. Am I missing something obvious.
[/quote]
The principle is right, but with a 1" bit, already projecting far enough for the top bearing to reach the template, will you have enough plunge travel to plunge a further inch?

Norris makes a very important point, by the way. With routers it's multiple passes taking off small increments that's the order of the day!

[Andyjr1515]

[quote name='scojack' timestamp='1472162052' post='3119103']
+1 (Think weve all done this, i certainly have).
I do 3mm at a time, you should hardly get any resistance,that way you can feel straight away when something goes wrong .
It's good to get into the habit of checking the bit and depth stop are tight every time you pick the router up, works for me but then i'm getting doddery.
[/quote]
..and Ian (Scojack) makes the same point!

[3below]

Agree on small passes, deeper template and shorter cutting length next time which will assist this in the initial stages. Checking bit depth, own goal on my part. It has always worked before Much more attention will be paid with the neck pocket.

[Andyjr1515]

The only reason that there's so much 'good advice' from us all is that we've ALL scored a few home goals with routers!

[6v6]

+1 on thick template and small passes (and the smaller template bit) - I learned this the hard way this week and ruined both the template and what I was routing (doh!), so easily done!

Build looks great despite the hiccups!

[Norris]

For internal routes such as control cavities you may find it easier to use a guide bush. Then you can use thinner templates such as 6mm MDF and get a longer plunge. It does mean calculating an offset (the guide will be a larger diameter than your bit) but you don't need a bearing on your cutter.

Edit: And it's safest to do a test route on scrap wood first to check you've got the offset right (yep, I've had to re-make a couple of templates, but better than getting it wrong on the guitar!)

Edited August 26, 2016 by Norris

[3below]

+1 on guide bush and the scrap practice. The neck pocket will certainly have some test pieces first. If I routed cavities as big as this again, I think I would probably fabricate a larger sole plate for the router (I have thought about this when ding previous edge roundovers as well). Previous experience and methodology went West yesterday - I blame the brain fog from being ill . All good fun on the learning curve and nothing that can't be hidden. I am resisting the urge to clean the upper cavity up, it might be tempting fate and once the top is on it will never be seen (hopefully).

No further progress this weekend and despite being retired start a new job on Tuesday (of my choosing and my terms).

Edited August 26, 2016 by 3below

[3below]

Back to it with brain now functional. .





Neck template (headstock detail not finalised yet). Again found that no 4 hand plane is a thing of joy to use when smoothing down the bandsaw ripples. Router locking and depth stop fettled and now working which resulted in problem free routing of the truss rod channel. Camera makes channel look more 'off centre ' than it is. Despite care setting up it ended up about 1 mm off the centre line, not world ending though. Had to open the channel out at the adjuster end using a chisel. I even succeeded at my bete noire, chisel sharpening.



Dabbed some lubricating wax on the truss rod screws. Covered rod with masking tape and clamped and glued the fingerboard on. Whether the glue fingerboard on then shape is a better approach than shape then glue remains to be seen. The Irwin clamp copies in the background are a waste of time, they worked well for about a year but now do not exert any real force. Should have bought the real thing in this case.

Edited September 6, 2016 by 3below

[Andyjr1515]

Looking good . My preference is how you're done it - fretboard on, then shape it. It makes it much easier to clamp it properly.

You are also right about ratchet-type clamps. They are great for holding things while you position, but useless for exerting the types of forces needed to glue panels and fretboards. Screw-type clamps (sash, C, F or whatever) are all much better at that job!

You are also right that 1mm off-centre in your truss rod channel isn't going to affect anything

So, Mr 3below, that's 3 out of 3 correct which, by my reckoning, is 100%

[3below]

Why thank you A much better day than the last time. Headstock now profiled to 15mm (allowing for smoothing) and neck bandsawn to slightly wider than template. It now starts to look like a bass neck (Photo to follow). Creeping small errors though, my laminations in the neck have ended up not being square. Again not a critical show stopper, just annoying when I get into perfection mode. I am reminded of my school woodwork lessons, 'Face, Face edge', all those lessons with a try square are flooding back. Somewhere on this journey, despite taking time to square up planer etc, check stock I have blundered (thinking about this some more I suspect I know where the issue started). Next time perfection

Edited September 6, 2016 by 3below

[3below]

Neck now profiled, fingerboard and headstock still to finalise. Did back of neck first as this allowed clamping against the flat fingerboard. The Fender type bolt on heel and headstock style will give a flat clamping surface when the fingerboard is radiused. I am leaving the headstock shaping until the last stage thus preventing damage by dings (my careless handling) etc.







Pictures not great, should have used different camera angles.

Neck profile was all done by hand: shinto, file, scraper, sanding blocks and emery cloth (the oak is so hard it just ignores sand paper). Initially I was apprehensive about profiling the neck. After watching videos / Internet research I had considered: jig(s) for router, sanding belt, sanding belt and cam jig, 3/4" radius router bit in jig or router table (yikes). I thought I would need various profile templates to get the shape correct. In the end I just got on with it by hand, after all double basses, cellos etc are all hand shaped. It was straightforward and did not take much more than an hour from start to finish. The most surprising part was that I did it all by eye and hand with only one measurement. The one measurement was to confirm what my hand was telling me, there was a slightly thick portion at one point. Measurement revealed all - 1.5mm in 26mm. It is fascinating how hand / eye coordination intuitively sharpened up as the level of detail finishing progressed. All in all I am pleasantly surprised at how easy and satisfying this stage has been. I have a neck that suits my hands, it is a "baseball bat" as planned. No mistakes today

Edited September 11, 2016 by 3below

[Andyjr1515]

Excellent work, 3below

I also basically do the neck profiles by eye and feel. I actually rough out with a spokeshave first but pretty quickly move onto the humble scraper. Much more controllable and, as you say, it really doesn't take long.

The bit where I'm a bit unconventional is that I do the final, final scraping once the bass is finished and all strung up. Then I can really feel whether it plays comfortably.

I'm very impressed with your build - top notch

[3below]

[quote name='Andyjr1515' timestamp='1473621876' post='3131762']

The bit where I'm a bit unconventional is that I do the final, final scraping once the bass is finished and all strung up. Then I can really feel whether it plays comfortably.

[/quote]

And thank you again . I can see myself doing a final scraping / fettling with the bass strung up before finishing . I am finding that my level of 'perfection' and attention to detail is increasing as the build progresses (some old skills being re-awoken). 'Top Notch' will be getting a finish approaching one of yours, you have set the bar high Andy!

[Norris]

Nice work. It's amazing how the fingers can feel what the eye can't see. Neck shaping is over too quickly - it's very therapeutic

[3below]

Small steps onwards. Headstock shaped and showing very approximate position of machine heads (stuck on with blu tack).



The design will work with straight string pull, it is an amalgamation of two basses in my possession. As always after the event I can see minor details that I would do differently next time. The upper 'A' string oak strip should be a bit larger, in keeping with 'd' string piece. However next time I would stick to 5 laminations and not put the extra stripes on headstock (another miscalculation). It is as if I have to make mistakes in order to fix them and the underlying issues in my mind and thus prevent next time. This might be due to needing to do more woodwork