Winter Build Off 2018 - Idle Hands are the Devil's Walnut

[MPU]

I like the chambering....Now you are getting into tuning the sound of the bass. Those chambers aren't going to do a whole lot, because the central spine will still be quite stiff. But, if you were to start softening the central spine by routing some long slots in it, then it will start having an effect. Cutting away wood and making the body softer (weaker, more flexible) will bring out overtones and richness in the midrange.

What kind of chambers sizewise would you route for first try of ”softening” the central spine? I’m in the planning stage of a bass and I’d like to try out this softening as well as your truss rod, Brucebars and brass block for bridge/body joint. I’m making an alder body if that matters.

 

[TundraMan]

I'm getting pretty close. The simple truth, however, is that I no longer have the strength or endurance in me to hand sand body wings to shape. I'm seriously considering moving over to the template/rout method for body wings, especially when working with walnut. Tear out be damned. I can work on this for about an hour each day. Then I feel like I need a nap. Then I'm groggy for the rest of the day. Criminy.

After having the router tear out on me time and time again regardless of what I tried to alleviate the issue, I've given up on that method.

Now I use my template to draw the line on the body, then I set the template aside. From there I just bandsaw extremely close to the line and then sand up to the line on the oscillating spindle sander simply using my eye. No tear-out, and the body edges are nice and smooth.

It took a little practice to develop the skill so that my curves were smooth without flat spots. The trick is to always keep the piece moving and not take too much off at a time and just sneak up on your line. Once I got good at this method it takes me no more time than setting up the router. The lack of worry about the router bit grabbing hours worth of work and tossing chunks of it across the room was worth the time invested in honing my ability. As a bonus, it's more fun than routing. Gives me kind of the same feeling as carving a neck.

Is it as precise as a router/template method? No. Is it close enough that the differences can't be seen by eye? Yes.

 

[Jisch]

Now I use my template to draw the line on the body, then I set the template aside. From there I just bandsaw extremely close to the line and then sand up to the line on the oscillating spindle sander simply using my eye. No tear-out, and the body edges are nice and smooth.

I do the same, the added bonus is that if there's a particular grain in the wood that fits with an arc or whatever I can adjust the shape accordingly.

 

[Bruce Johnson]

After having the router tear out on me time and time again regardless of what I tried to alleviate the issue, I've given up on that method.

Now I use my template to draw the line on the body, then I set the template aside. From there I just bandsaw extremely close to the line and then sand up to the line on the oscillating spindle sander simply using my eye. No tear-out, and the body edges are nice and smooth.

It took a little practice to develop the skill so that my curves were smooth without flat spots. The trick is to always keep the piece moving and not take too much off at a time and just sneak up on your line. Once I got good at this method it takes me no more time than setting up the router. The lack of worry about the router bit grabbing hours worth of work and tossing chunks of it across the room was worth the time invested in honing my ability. As a bonus, it's more fun than routing. Gives me kind of the same feeling as carving a neck.

Is it as precise as a router/template method? No. Is it close enough that the differences can't be seen by eye? Yes.

That's the general approach I use too, for body perimeters. I build my bodies as a top and a back, of equal thickness (0.700" on most of my models). Before cutting out the perimeter on the top and back, I do all the internal routing of cavities and chambers. This is done with routing templates that fit into reference holes on the inside surfaces of the blanks.

When the internal chambers are done, I use my Master template to draw a pencil line of the perimeter on the top and back. The Master template also pins into the same reference holes. Then I bandsaw out the perimeter on the top and back, cutting real close to the pencil lines. Next, I glue the top and back together, using permanent (plastic) dowels in the reference holes to line them up. The perimeters are a pretty close match, within 1/16". I finish up the external pocket routing; neck pocket, control cavity cleanout, etc.

I finish up the perimeter as the final step in making the body. All the other stuff needs to be located accurately, but the perimeter doesn't need to be precise dimensionally. It just needs to look good. I clean up the perimeter on the spindle sander and the end roller of my edge sander, and then work it in the vise with hand sanding blocks. It's still a squared edge, but it's important to get the shape smooth and fair (a boatbuilding term). You shouldn't be able to see or feel any lumps or discontinuities in the perimeter shape.

Then I go over it with the router and a big roundover bit, from the top and the back, to get the radiused edges I want. It's a bearing bit, with the bearing following right on the glue line. That's why the perimeter needs to be fair, so the radiuses will also be fair. To avoid tearout, I go around in several steps of depth of the bit. The last pass goes in the climb direction, and only takes off about 1/64".

Using that sequence, the final perimeter is usually pretty good, requiring only a little bit of light sanding with a rubber block.

 

[Andyman001]

bonus points for "discontinunities". haven't heard that since NDT class.

 

[TundraMan]

That's the general approach I use too, for body perimeters. I build my bodies as a top and a back, of equal thickness (0.700" on most of my models). Before cutting out the perimeter on the top and back, I do all the internal routing of cavities and chambers. This is done with routing templates that fit into reference holes on the inside surfaces of the blanks.

When the internal chambers are done, I use my Master template to draw a pencil line of the perimeter on the top and back. The Master template also pins into the same reference holes. Then I bandsaw out the perimeter on the top and back, cutting real close to the pencil lines. Next, I glue the top and back together, using permanent (plastic) dowels in the reference holes to line them up. The perimeters are a pretty close match, within 1/16". I finish up the external pocket routing; neck pocket, control cavity cleanout, etc.

I finish up the perimeter as the final step in making the body. All the other stuff needs to be located accurately, but the perimeter doesn't need to be precise dimensionally. It just needs to look good. I clean up the perimeter on the spindle sander and the end roller of my edge sander, and then work it in the vise with hand sanding blocks. It's still a squared edge, but it's important to get the shape smooth and fair (a boatbuilding term). You shouldn't be able to see or feel any lumps or discontinuities in the perimeter shape.

Then I go over it with the router and a big roundover bit, from the top and the back, to get the radiused edges I want. It's a bearing bit, with the bearing following right on the glue line. That's why the perimeter needs to be fair, so the radiuses will also be fair. To avoid tearout, I go around in several steps of depth of the bit. The last pass goes in the climb direction, and only takes off about 1/64".

Using that sequence, the final perimeter is usually pretty good, requiring only a little bit of light sanding with a rubber block.

"Fair" I like that term. I know what I'm looking for when I'm running my hand on the sanded curve. Now I also know the term for it.

 

[Bruce Johnson]

What kind of chambers sizewise would you route for first try of ”softening” the central spine? I’m in the planning stage of a bass and I’d like to try out this softening as well as your truss rod, Brucebars and brass block for bridge/body joint. I’m making an alder body if that matters.

Well, the internal chambering to soften the center area of the body can be almost any shape. You are just cutting away material and making holes to weaken the beam. One consideration is that you don't want to leave large thin areas on the top and back, which could get broken later. An easy starting point is simple slots, parallel to the center line. Use a 3/8" bit and rout straight slots, a little over 3/8" wide, leaving about 1/4" walls between them.

I did the straight slots like that on some of my early instruments, when I was experimenting with softening the bodies. Once I got a feel for about how much wood to remove, I reworked the design into about 5 odd-shaped chambers that fit around between the various features of the body. The final shape of the chambers was also dictated by making up a simple sequence of routing templates, where the templates are used to cut alternating chambers.

 

[Bruce Johnson]

"Fair" I like that term. I know what I'm looking for when I'm running my hand on the sanded curve. Now I also know the term for it.

I've never tried building a boat, but I've learned a lot from reading books about wooden boatbuilding. I subscribed to Wooden Boat magazine for years. Some very useful woodworking techniques are used in that trade, especially to do with laying out and cutting complex curved shapes. Like musical instruments, there are hardly any straight lines on a boat.

 

[Gilmourisgod]

I've only ever used the Robosander for body outlines, and it works pretty well, though slowly. I've seen a lot of curly maple necks on TB, I can't believe everybody is sanding all those straight edges. Even with a template roller on it, I don't think a Robosander will produce a perfectly straight edge. How are y'all avoiding tearout on curly maple?

 

[TundraMan]

I've only ever used the Robosander for body outlines, and it works pretty well, though slowly. I've seen a lot of curly maple necks on TB, I can't believe everybody is sanding all those straight edges. Even with a template roller on it, I don't think a Robosander will produce a perfectly straight edge. How are y'all avoiding tearout on curly maple?

I've just given up routing body outlines and headstocks.

I do still taper the sides of my necks with a pattern bit in a router using a straight edge as a template. Tearout is rarely a problem as this type of routing doesn't deal with end grain. Still, I try and cut close to the line so the amount of wood I'm removing with the router is very small, usually less than 1/16".

 

[Gilmourisgod]

I've just given up routing body outlines and headstocks.

I do still taper the sides of my necks with a pattern bit in a router using a straight edge as a template. Tearout is rarely a problem as this type of routing doesn't deal with end grain. Still, I try and cut close to the line so the amount of wood I'm removing with the router is very small, usually less than 1/16".

I can see that working fine on neck sides, where the curly grain isn't popping, how about the top and bottom faces, where the curly maple grain is most prominent? Is it possible to thickness (top to bottom) a curly maple neck beam with very light router cuts without tearing the hell out of it? If I had access to a panel sander, I'd use it to thickness anything to do with curly maple!

 

[TundraMan]

I can see that working fine on neck sides, where the curly grain isn't popping, how about the top and bottom faces, where the curly maple grain is most prominent? Is it possible to thickness (top to bottom) a curly maple neck beam with very light router cuts without tearing the hell out of it? If I had access to a panel sander, I'd use it to thickness anything to do with curly maple!

Ah, gotcha. The faces of curly maple necks.

This is where having access to more tools is beneficial. I generally cut them close to correct thickness at the band saw, then run them through my drum sander (old Performax 10-20). I then joint the face straight on my jointer.

I have my jointer set to just cut a whisper at a time. This means I have to run the pieces through bunch more times until they are perfectly straight as it's barely removing any material with each pass. However, having it set up this way means I rarely get any tear out, and any small bits are generally covered up when I glue the fretboard in place.

 

[mapleglo]

On my first build, I did the router/template method and had to throw away the first set of body wings. Since then I've been bandsawing (or jig sawing before I got the bandsaw) to get the rough shape, and then sanding to size. I guess I'll have to eat some wheaties and continue to do that.

 

[mapleglo]

I'm all set to start slotting the bird's eye maple fretboard.

Fretting

• mapleglo
• Feb 20, 2018
• fret

Starting to fret

Just waiting for it to warm up a bit in the shop.

I also received the replacement Delano template from Best Bass Gear. It's slightly larger, by just a tad. I like a little more room, but I'll enlarge the rout per the new template and see how it fits.

 

[mapleglo]

Jewelry Babicz solo rail bridge pieces arrived.

Solorails

• mapleglo
• Feb 20, 2018
• babicz

Babicz solo rails

 

[ctmullins]

Looks like jewelry to me! Make sure they’re adequately insured.

 

[mapleglo]

I have to say, having the right tool for the job is a pleasure.

Slotting

• mapleglo
• Feb 20, 2018
• fretting stewmac

slotting frets

Slotting this fretboard with the StewMac miter box is like - dare I say - buttah.

 

[Jisch]

I am contemplating buying one of those slotting jigs. I almost pulled the trigger the other day.

 

[ctmullins]

Me too. Want to do a fanned fret soon, and LMII doesn’t do those...

Edit: duh, never mind. That miter box limits the saw to cutting perpendicular slots...

 

[mapleglo]

Me too. Want to do a fanned fret soon, and LMII doesn’t do those...

I'm not sure this one will do a fanned fret board either. To be honest, I never looked into it, but I don't see how it would do it. Of course, just because I don't see it, doesn't mean it can't happen.