Multiscale Bass Build

[SlingBlader]

Hello everyone. It's been a little while since I've posted a build thread, so here we go.

I've been wanting to try my hand at building a multiscale instrument for a while, so a few weeks back I put pencil to paper and starting to draw something up. Most of the basic geometry will be based on Dingwall specs. They already have this stuff figured out, so why try to reinvent the wheel on my first attempt?

Some basic starting points and specs:

• 4 Strings
• Bolt on neck, 21 frets
• 36.26-34" scale lengths
• Multi-lam neck (maple, mahogany and bloodwood)
• Poplar body with figured maple top
• Tapered or possibly carved body wings
• Most likely a trans white finish on the top and solid white on the rear of the body
• Bound body and neck (think reverse LP custom binding)
• 2 Lace bass bar pickups with coil split switches
• Audere 4 band active preamp

I want the body style to be in the Gibson reverse Thunderbird, RD or Explorer vein stylistically, but I know those are very prone to neck dive. I also didn't want to do an exact copy, just pull some of the lines from those models and put my own twist on it.

So, I drew out the neck and scale dimensions, then I started in on the body shape. I began with an outline of the RD body shape. Please excuse the shadow.

I overlaid this with additional pieces of paper to modify different sections at a time. Anyway, this is where I landed:

I would normally do a 24 fret neck, but 21 frets seemed to make more sense. I was able to connect upper bout at the 14th fret, which should help with neck dive issues, but who knows?

Oh, I should also mention, this will be my first time jumping into using automotive urethanes for the finish. I have a decent amount of experience with nitro, but very little with auto paints. I've purchased a better exhaust fan and am looking at a little bit better spray "booth" situation. The driving force for me is to be able to wrap up shooting in 1 to 2 days and start leveling/polishing a couple days after that rather than the usual 3-4 week wait.

Anyway, let me know what you think of the body design and build plan. I'll post some progress shots as I get going.

 

[Skyjerk]

I like the design, but I’ll just have to imagine it finished cuz I can’t look at multi-scale stuff.

 

[SlingBlader]

Well, I got things rolling on this project and knocked out a couple of items on the check list.

I got templates for the body and headstock completed using some 1/4" sheeting that I had leftover from a flooring project. Upcycling!

I cut a couple of chunks of poplar for the body.

I trimmed those down to size, jointed the glue seam and got it clamped up.

Flattened and cleaned up the body blank on the drum sander.

Marked the body outline on the blank ready to be cut out.

More soon.

 

[SlingBlader]

I like the design, but I’ll just have to imagine it finished cuz I can’t look at multi-scale stuff.

Well, I guess I can't please everyone all the time.

 

[Skyjerk]

Well, I guess I can't please everyone all the time.

Plus I'm particularly old and closed minded so its a tough sell

 

[SlingBlader]

Well I made a little progress on this project. I prepped up the neck laminates, which consist of hard maple, mahogany, bloodwood and black-dyed poplar veneer. I rough cut those on the band saw, then finished them on the drum sander.

Clamping fixture at the ready, glue is mixed and ready for glue-up. The clamping cauls that I made are tapered, so that I can glue up tapered neck blanks, but will still clamp "squarely". For this particular glue-up, I've flipped one of the cauls so that the angles offset and make a set of square cauls.

All 13 pieces (7 primary laminates + 6 pieces of poplar veneer) are glued and clamped with UF glue. That will sit for a few days before I touch it.

While I had the band saw out, I cut up a nice chunk of black and white ebony. One of those will become the fretboard for this build.

More soon.

 

[Skyjerk]

sweet jig.

I can watch everything except when you install frets, so ill be following closely till then

 

[SlingBlader]

Small update tonight. Got the body cut out with a wide margin for error for upcoming operations.

Also got the maple top jointed and glued up with HHG.

More soon.

 

[SlingBlader]

sweet jig.

It's really handy. I unashamedly stole it from Randall Fulmer (Wyn Guitars), I think I saw it in one of his videos. It's very simple and is just made from 2x material.

I used a couple of 2x2s for the rails to hold the clamps. I cut matching slots wide and deep enough to hold F clamps. The two support pieces are just chunks of 2x4 with a shallow peak on the top, which is where the cauls and workpiece sit. The only thing to keep in mind here is that the height of the supports holds the cauls so that they are clamped roughly at their mid-point.

Glamor shot of one of the supports. I rub paraffin on the tops of these, just in case of glue drips. I try to remember to cover the supports and clamp bars with parchment or wax paper... but that doesn't always happen.

Here is a low-angle shot the shows the clamps hitting the mid-point of the caul. The cauls are make from laminated pieces of 2x4 and are fairly rigid. They really help to evenly distribute the clamping pressure across the neck so that you don't get "hot spots" in the beam where the clamp pads land.

And this shows the top view with the cauls in place. Again, mine are tapered so that I can either glue up tapered neck blanks, or flip one to glue up a square blank. Either option allows the clamps to work "squarely", for lack of a better term. Again, the cauls are rubbed generously with paraffin. The entire fixture is over 50" in length so that I can glue up neck-through bass blanks.

And here is the current blank as it came out of the clamps. I cleaned up one side with hand planes, then sent it through the drum sander to square it all up.

Great result!

I also trued up the maple drop top.

More soon.