Finished pics! Psilos Ultra-modern bass build

[Andyjr1515]

I think I've sorted the final prototype rig - how to get a hidden magnetic pickup close enough to the strings...

Forgive the knotty softwood I used but I rigged up a version of the above concept.  The pickup I have at hand doesn't have screw-poles but I have one on order that does.  Pretend it is that I am using.

Here's basically how the pickup will be fitted at the back of the bass (it will have a cover flush with and matching the neck):

 

From the top with the fretboard removed (remembering there will be the four screw pole pieces):

 

Then using the carved archtop thickness carving trick:

...

...a slot is carved into the back of the radius-profiled fretboard around 1mm- 1.5mm from breakthough:

 

Once the fretboard is fitted the slot will correspond to the pole-pieces on the pickup:

 

Wind up the pole pieces as far as they will go in the space and, from the top, it looks like this:

...but the coil is actually only 4mm from the fretboard top and the pole pieces are 1.5mm from the top.  This should mean poles 3.5mm or so from the strings and the coil around 6mm

- this should work  

[mattharris75]

Very cool. And I love how you're testing your ideas. Can't wait to see how this one turns out.

[ScottR]

It's probably a good thing there will be no frets in your fretboard....

I love watching you put these ideas together. This will without a doubt be one of the most unique builds we've had in some time.

SR

[Andyjr1515]

2 minutes ago, ScottR said:

It's probably a good thing there will be no frets in your fretboard....

I love watching you put these ideas together. This will without a doubt be one of the most unique builds we've had in some time.

SR

Ah...well...hmmm...it IS going to be fretted.  24 of the little beauties 

[ScottR]

3 minutes ago, Andyjr1515 said:

Ah...well...hmmm...it IS going to be fretted.  24 of the little beauties 

I knew I should have double checked that..... So this pickup is going under the part of the fretboard beyond the 24th fret? Which makes perfect sense of course.

SR

[Andyjr1515]

1 minute ago, ScottR said:

I knew I should have double checked that..... So this pickup is going under the part of the fretboard beyond the 24th fret? Which makes perfect sense of course.

SR

Yes - should be pretty much where a neck pickup would normally go.

[Andyjr1515]

OK - with the concept sorted, it's time to start cutting wood :

Don't look at the appalling mess behind the bandsaw.  Depending how big the piece of wood is depends whether you get a shot of the mess or the more tidy and ordered part of my cellar-workspace.  This bandsaw is the smallest bearing-guided one I could find, but the biggest I could actually physically get into the cellar.  I have it on a very neat 'lift and move' wheeled trolley so, where the length is needed (like here), I just foot-pedal lift it onto castor wheels, pull it out of its normal station and twist it round 90 degrees then lower it back onto its fixed feet.  Then when it's done, just reverse the operation and pop it back into its (relatively) neat station.

Anyway, 10 minutes later we have something that is starting to look much more like a bass! 

[mattharris75]

Looking good.

And that Axminster bandsaw has some striking resemblances to my 12" Craftsman bandsaw... I think the Craftsman was actually build by Rikon, and yours seems to share some components, so maybe it was as well.

[Andyjr1515]

On 4/18/2017 at 3:18 PM, mattharris75 said:

Looking good.

And that Axminster bandsaw has some striking resemblances to my 12" Craftsman bandsaw... I think the Craftsman was actually build by Rikon, and yours seems to share some components, so maybe it was as well.

Yes - we also have a brand called Record in the UK and I'm pretty sure their 250 model is also pretty much the same   Certainly, their drive belt fit fine as a replacement for the poor floppy one that came with the Axminster saw! 

[Andyjr1515]

Mick has sent me the neck profile measurements of his favourite player so that, as far as possible, I can replicate the general 'feel':

Ahead of gluing anything together, I've also done some sketches to get my head around how the single-cut transition of the neck will work:

In the meantime, I've done a bit of work to the neck - routing the truss rod slot and band-sawing the taper. Single cuts throw an interesting challenge ref the taper, more of which later when you see what I'm planning with the fretboard  

 

[psikoT]

Can you work faster, please? I can't wait to see this done! 

[Andyjr1515]

One of the things that I've been working on is the possibility of using some custom pickups to avoid having to cut all the way through the neck.  With the help of Mick, whose used the guy before, we've got a thumbs up on a set of individual coils for each string.  This is the layout we've agreed:

The coils will be around 18mm x 18mm and the magnetic poles will be adjustable from the back.  This means I can retain the hatchless continuous fretboard as the coils themselves will be inserted from the back too into a series of four 20mm holes drilled through the neck and covered with a hatch using an offcut of 'stripey' neck wood, with a foam pad keeping the coils pressed up against the fretboard.

What I have done, to prevent encroaching into the body wings, is add a couple more ebony strips to widen the neck over the body length.  

Here's the rear view:

 

Now I can start preparing the neck ready for gluing the wings.  First job is recreating the platform for the upside-down tuner block to fit into, per the mockup, sectioned here:

This bit's a bit scary.... 

[ScottR]

It looks like you're working with some fairly tight tolerances, Andy.

SR 

[Mr Natural]

this is crazy complicated- cant wait to see it.

[Andyjr1515]

17 minutes ago, ScottR said:

It looks like you're working with some fairly tight tolerances, Andy.

SR 

Mmmmm.....there's one bit where the body thickness (carved top and bottom) has got to be sub-millimetre accurate...

[Andyjr1515]

32 minutes ago, Mr Natural said:

this is crazy complicated- cant wait to see it.

Great, isn't it    

As mentioned at the beginning, it's why, on another forum, I've titled the thread 'A Bridge Too Far?'....because it might well be....

[curtisa]

That's not the attitude. This should be a triumph of British engineering at its finest.

And not in a British Leyland kind of way. 

[Andyjr1515]

19 hours ago, curtisa said:

And not in a British Leyland kind of way. 

You beat me to it 

[curtisa]

Unfortunately, I think eveyone beat British Leyland to it.

[Andyjr1515]

The better I get at sharpening and using chisels, the more I use them in preference to the 'you-can-destroy-everything-in-seconds' router.

 

The slot here will be where the tuner block butts up against the body wing.  I'm pleased with this feature - it really does mean the tuner block isn't going to go anywhere and is not reliant on the fixing screws at all for strength .  This is basically how the block will fit:

 

The pencil marks shows the positioning of the neck.  Not that there will be a rebate at the top and the bottom of the body.  You can see the top one here - the top wing is glued and the bottom wing not yet glued:

 

The top rebate is where the full-length fretboard will slot into and the similar rebate at the bottom is where I will carve up to the neck to create the back curve.

You can see also here the slot where the strings, attached to an upside down tuner block attached to the rear block, will come through the neck and through the fretboard.

 

Next is to sit and think and plan and think again.  I need to make sure ALL of the control run slots, etc, are properly thought through and in place before I glue that bottom wing on!   

[Prostheta]

Oh, nice work Andy! You really seem in your stride at the moment.

[Prostheta]

Andy - if you haven't already done so, epoxy a strip of leather to a piece of wood and use that to strop your chisels. Unless you're really hitting them, it'll give you several times the useful life between sharpenings:

 

I just draw the back of the chisel down the strop with a little Autosol added. It's essentially a paste form of white blizzard metal polish, and perfect for honing. My strop boards slot into my workbench's centre helper board.

[Andyjr1515]

1 hour ago, Prostheta said:

Andy - if you haven't already done so, epoxy a strip of leather to a piece of wood and use that to strop your chisels. Unless you're really hitting them, it'll give you several times the useful life between sharpenings:

 

I just draw the back of the chisel down the strop with a little Autosol added. It's essentially a paste form of white blizzard metal polish, and perfect for honing. My strop boards slot into my workbench's centre helper board.

Great tip, Carl - thanks  

Leather stropping is one of those things I keep remembering and then keep forgetting again!   I'm old enough to remember the barber stropping the cut-throat before every shave!  As a six year-old waiting for my pudding-basin cut, I was fascinated.

I'll rig something up...

What kind of thickness of leather should I be looking at?

[Prostheta]

I'm not sure exactly. I used what was on hand, and that's maybe 2-3mm thick. The ideal choice isn't known to me, however this works. I'm sure that the slightly amount of conformity in the leather because of its thickness may work against it, but I don't notice much deformation unless is am drawing back the bevel itself. The back has such a large surface area that it stays nice and flat.

There is a little conformity though, as the corners polish up a little faster than the edge. That's no big issue unless you really really need a laser-straight edge.

[Andyjr1515]

I'm rapidly reaching the stage where I have no excuses to gluing on the second body wing.... 

The control run slots are cut and rounded to try to prevent snagging, and the second tuner-block locator slot is done:

There will be a decorative wedge at the back so the block doesn't look like it's hanging in mid air, but this is broadly how it will fit:

 

The ebony overlap will be cut before I glue, now I know exactly where the wing is going to join.

Once thing I'm pondering on is whether to use epoxy rather than titebond for the join - there isn't a huge amount of adhesive area and I'm never sure how well the very tight-grained ebony bonds with titebond.  I know it's not oily, but hmmm...what do you reckon?