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I am a big fan of Rob Allen basses. I am not, however, a big fan of how much Rob Allen basses cost. I don't think they are overpriced. In fact, I think he could get away with raising his prices a bit. I just don't have $3k to put into a bass.

With that in mind, I set out to build my own. This build log is also posted at TalkBass, but some friends asked me to post it here too. Right now, the bass isn't too far from being finished. I think all shaping will be done within a couple of weeks, with finishing taking a while longer.

This is my third build. It is based on my first build, but modified quite a bit. I started (and aborted) another build that was number 3, but wood problems have made me abandon that particular build. It just wasn't happening the way I wanted it to be, so I scrapped it.

So here goes:

[SIZE="4"]Chambered 4-String Fretless Bass[/SIZE]

Specs:
4-strings
Fretless with lines (white plastic lines)
Chambered Ash body with walnut top
Ebony fingerboard, 10" radius
5-piece bolt-on mahogany, walnut, and maple neck
Ebony bridge (now bloodwood)
EMG AT-125U undersaddle piezo pickup
Graphtech TUSQ saddle
Hipshot Ultralite Tuners (now Gotoh)
Cafe Walter PZP-1 piezo buffer pre-amp, 9v
Passive Tone and Volume Controls
Grizzly Dual-Action Truss Rod
Sadowsy style aluminum knobs

Here's the overall design:


I have ordered these templates from Ronny Trigo at GuitarBuildingTemplates.com.

I used a custom template from Ronny with my 7-string baritone project, and I was very pleased with the results.

The bridge will be shaped from ebony (bloodwood), and will look like this:


Here's the ash:


And the walnut billet:

This is from Goby Walnut in Portland.

And here are the neck woods:

It'll be 5 pieces: Mahogany, Maple, Walnut, Maple, Mahogany. The Mahogany bits will be roughtly 1.5" wide each before shaping. The maple strips are 1/8 thick wide, and the walnut stip is 1/2" thick.

The plan for constructing the neck is as follows:


(I executed this plan as shown above, and it worked out perfectly. I got 2 neck blanks out of it.

And finally, here are all the parts I have so far:

Not pictured is the EMG undersaddle pickup or the Gotoh tuners. They are around here somewhere, just didn't make it into the group photo.

Neck woods ripped to size:



And glued:



And resawn:



And the neck blank is surfaced, scarf is cut, and trimmed. Headstock is trimmed, glued, and clamped.



Body ash is jointed, glued, and clamped.

The neck has been mostly cut out. Next step is to cut out the headstock and glue on the fingerboard.



There was some router yanking when routing the TR channel, but luckily it did not go outside the lines, so it'll be covered up by the headplate. I'm a bit annoyed by it, but I filled the blunder with a sawdust+epoxy slurry.

Then I glued a walnut veneer over it:



I glued the walnut veneer on the headstock and made a little truss rod cover test:


Then cut the headstock out with a scrollsaw:



Then I trimmed it up and smoothed it out with an oscillating spindle sander:


And here it sits now:


The fingerboard is tapered, but has about 1mm of overhang on the sides. I'll trim it up after it's glued on.

The top edge of the headstock is chamfered to 45 degrees. I wanted the neck laminate to be able to just peek through the front. I'm happy with the effect. There was a little scorching due to my hesitation with the chamfer router bit. I'll file that away when I clean up that corner.

I also made a little TR access cover (shown above). It's just a piece of black pickguard material with maple and walnut veneer layers glued onto it. Then trimmed on the spindle sander and "finished" with hand-sanding.

So I made a couple of truss rod access covers:



The smaller one is walnut veneer, maple veneer, and black plastic pickguard material. The larger one is walnut veneer, maple veneer, walnut veneer, and a bit of 1/8" thick maple. They are the same color on the top...the picture sucks, I guess.

Here's the larger one, fitted to the neck:



I'm still a big n00b, so I can't countersink correctly.

Fingerboard lines are glued in and sanded down:


And the walnut plate is resawn, jointed, planed, re-jointed and glued together:



The ebony stock I have for the bridge turned out to be too small by about 1/16" (1.5mm). So I decided to use a really nice piece of bloodwood for it.



It's the most dynamic bloodwood I've ever seen. Aside from looking more blood red than brick red, it shimmers and shines in changing light. It's really pretty intense. To make it "fit", I'm also going to remake a new truss rod cover out of the same stock. I may make the rear cavity cover out of the same thing too.

~~~

Bloodwood TR cover:


Shaping the bridge:

First I attached the template and drilled the string-through holes:


Then I scribed the contour lines with an awl and started sanding the contours with the spindle sander. Sides first:



Then the front edge:


Then I radiused the top with a 10" radius block (to match the 10" radius of the neck):


Then I used the same radius block to slope the the top of the bridge down toward the back:


I'm pretty happy with how it is coming along. I need to build a slotting jig and acquire a plunge router (or plunge base for an existing router) before I can cut the saddle slot. But...it looks good, and I'm pleased.

I think the bloodwood bridge with matching truss rod cover and electronics cavity cover will be nice colorful accents to the rest of the bass.

Routed the body chambers in the ash:



Fitted the TR cover:



Cut the body out with a bandsaw, then trimmed it to the template with a router:



I also routed the control cavity opening:



Routed the battery box hole and rounded the back side:



Glued the top on and trimmed to the back.



Routed the top of the body today:



And trimmed the neck pocket:



It's a tight fit.

There really isn't much left to do on the body. I've got to drill the neck attachment holes, route the cavity cover recess, drill the output jack hole, and drill for through-body stringing. That's about it. I'm pretty happy with how it is coming out.

And that is how it sits right now.

That will have a stunning appearance when completed!
I like your bloodwood bridge, too.

_________________
"Act your age, not your shoe size" - Prince

Very nice! Really like the contouring and shaping on various items (bridge, headstock), giving me some design inspiration for a potential new electric project. Possibly even shape a metal bridge similar to the wood version (brass shapes pretty easily with a sander, after all..)

Thanks Chris and Mattia.

I'm thinking about scrapping the saddle and pickup idea, in favor of having a single monolithic bridge piece with a transducer attached to the bottom.

The primary reason is that I don't have the equipment or skills necessary to route a slot for the UST and saddle to go into. I'm also concerned that, even if I had a plunge router and made the jig and was confident enough to do it, the bloodwood would tear and chip when I hit it with the router.

Opinions?

Mark,

Bloodwood routs quite decently with sharp bits, always best to remove as much excess as possible, you could also cut a slot with a saw across the complete bridge and make a longer saddle, then fill under the saddle to make the space for the AT 93 or 125 that you plan for. You can also use a slightly larger bit than the planned slot size, and make a wider saddle the tapers to the top edge, thus filling the larger slot and still being aesthetically pleasing. There are 100 easy ways to get around doing an exact 3/32 or 1/8 slot for the saddle. Good luck, and it's looking great so far

Thanks JC. Fancy seeing you here!

~~~

I did some work on profiling the neck today. I mainly focused on the heel.





Still some tweaking to do, but I think it'll work out nicely.

And then I did a little more work refining the heel transition:



And the headstock:



You can see how the laminate didn't line up perfectly after the scarf glue. It's a fraction of a millimeter off. dang it. Oh well.

And here's the...curvy-ness:

That's lookin' mighty fine!
That top will look great uner finish,
as long as it isn't water based. "You can see how the laminate didn't line up perfectly after the scarf glue.
It's a fraction of a millimeter off. dang it. Oh well."
You sound like me.
Maybe you could knife in some slivers of wood to hide that?
It is on the back, so....

It would probably be in your best interest to send that to me for a thorough test playing before you sell it.

Thanks alan and jimmy.

Alan: I'm going with a Shellac finish on this. It will be my first.

I made the bloodwood electronics cavity cover today. That's 3 bloodwood parts total for this build. Here they are:



I cut the cavity cover on a bias because the wood kept splitting along the grain when I attempted to cut it "straight". Just need to drill the attachment holes on it. It doesn't fit as neatly as I had hoped. There is a gap on each end of about 0.5mm, but the sides are snug. It seems my templates weren't 100% accurate to the drawings I sent. It's close enough though.

Also did this:



And this:

I got the neck mounted today:


There is still a bit of cleanup to do on the neck heel to make the contours mate nicely:


Strings!


And whoops!

Due to the through-body stringing, the string silks cross the nut. I guess I'll have to try new strings.

Going to have to go with the undersaddle pickup. The soundboard transducer wasn't giving me enough output, even attached to the bridge.

Lookin' good!
Did you try running it through a pre amp?

Thanks.

And yep.

So I spent last night polishing the bridge. I was bored. I used StewMac's flexible polishing papers, up to 8000 grit. Today, I took a video which captured not only the polished shine, but the shimmer of the bloodwood's grain.

http://www.youtube.com/watch?v=ky_W99V2B18

Hey Mark...LOL yeah, it's funny where we pop up...LMAO I don't venture to many sites but this one looked a little more interesting. That bloodwood looks gorgeous. I have a piece like that I have reserved for a top at the end of my new resaw blades life, I"ll resaw it...LOL

This is looking just great, hope the transducer works for you. You might want to look at Dremel cutoff wheels to rough out the slot, inexpensive compared to bits, and easy to manipulate then clean up with router or moto tool router bit.