arch on the fingerboard

harveycrush · #1 05-24-2004, 04:14 AM

Anyone have any plans/tips/techniques for getting the correct arch on the fingerboard when making a double bass?

I am used to making guitars with a flat fretboard and I am finding it quite difficult to get this right.

Cheers, H

anonymous0726 · #2 05-24-2004, 09:09 AM

I've often seen forms that luthiers have laying around. Flat pieces that kinda look like a gradeschool protractor.

lemur821 · #3 05-24-2004, 04:39 PM

I'd use a radiused sanding block if I were you. You could use some self adhesive sandpaper on it. Unfortunately (for both of us), I don't know where to get these things. Anyone here know what kind of radius the uppright fingerboard has? Is it compound?

Bob Branstetter · #4 05-24-2004, 06:32 PM

The ebony fingerboard blanks from Germany are usually made with a compound radius. However, I've found that making the fingerboard with a constant radius of about 66mm works quite nicely. I use a specially made router jig to make my bass fingerboards. Basically it consists of a track that a router rides in over the length of the fb with the fingerboard shaped ebony board attached to what can best be visualized as a BarBQ spit. The "spit" turns side to side (the radius) while the router cuts from end to end. Making a jig like mine would probably be over kill for just making just one fingerboard, but that is the way I make them. Most makers prefer to simply buy a ready made fingerboard blank.

nicklloyd · #5 05-29-2004, 09:23 AM

Bob- you make your own fingerboards? That's pretty sadistic...
btw: how's yer knee?

LarvaeDrink- International Violin has affordable, good ebony/rosewood fingerboards. Also, I'd be happy to fax/mail (send me a pm) you a tracing of the fingerboard/bridge crown template that I use. Different players like different radii, but this template works for 90% of the bassists out there.

Bob Branstetter · #6 05-29-2004, 09:57 AM

Quote:

Originally Posted by nicklloyd

Bob- you make your own fingerboards? That's pretty sadistic...
btw: how's yer knee?

I've been making my own synthetic ebony (pakka wood) fingerboards for a couple of years. I buy my ebony boards just like everyone else.

The knee is coming along fine. I still have some pain, but the medication is now minimal. It's only been a little over 3 months since the surgery and I can do a lot of things better now than I could before the surgery. My only regret is that I didn't do it sooner.

nicklloyd · #7 05-29-2004, 10:16 AM

[quote=Bob Branstetter]I've been making my own synthetic ebony (pakka wood) fingerboards for a couple of years. I buy my ebony boards just like everyone else.

What's this about pakka wood? Wood you be able (sorry) to make a dozen and sell them to other luthiers?

Bob Branstetter · #8 05-29-2004, 11:53 AM

Quote:

Originally Posted by nicklloyd

What's this about pakka wood? Wood you be able (sorry) to make a dozen and sell them to other luthiers?

Pakka wood is made by impregnating a sandwich of hard wood veneers with a hard plastic material under high pressure and temperature. The raw material comes in sheets made to order by Fibron Products, Inc.. I was introduced to it several years ago by Paul Warburton and his luthier friend Bob Ross. Paul was playing one of the Ross/Warburton basses with a synthetic fb made by Bob Ross. With the wood grain from the veneers it's hard to tell from the real ebony until you get up really close. It's harder and more dense than real ebony and is very stable (no warpage). I've installed them on a dozen or so basses and everyone, myself included, loves them. The only negative is that hide glue will not stick to it, so you have to use something like weldwood glue to attach it to the neck or use another layer of wood in between that can be attached with hide glue.

Sorry Nick, but I don't have any plans to make them for sale to other luthiers. I made up enough boards the last time to last me for a year or two. Even with my big shop dust system attached to my router jig, the dust from making them gets all over everything in the shop. It has a strong, distinct odor while it is being machined and is mess to clean up afterward. My wife screams every time I make them.

Here's a photo that shows the wood grain of a couple of the synthetic ebony (Pakka Wood) fingerboards. The dull finish you see is as it comes from the router jig. It can be sanded and polished up to a dark black mirror like finish if you desire.

Mudfuzz · #9 05-29-2004, 03:25 PM

Quote:

Originally Posted by Bob Branstetter

The ebony fingerboard blanks from Germany are usually made with a compound radius. However, I've found that making the fingerboard with a constant radius of about 66mm works quite nicely. I use a specially made router jig to make my bass fingerboards. Basically it consists of a track that a router rides in over the length of the fb with the fingerboard shaped ebony board attached to what can best be visualized as a BarBQ spit. The "spit" turns side to side (the radius) while the router cuts from end to end. Making a jig like mine would probably be over kill for just making just one fingerboard, but that is the way I make them. Most makers prefer to simply buy a ready made fingerboard blank.

Is there any noticeable difference in feel between a compound vs. a constant radios? If not you just save me some work. I made a five string EUB and I need to tighten the radios to get better bow clearance, the FB has a constant right now but I was thinking of going compound when I reshaped it.

Bob Branstetter · #10 05-29-2004, 03:57 PM

Quote:

Originally Posted by A M N

Is there any noticeable difference in feel between a compound vs. a constant radios? If not you just save me some work. I made a five string EUB and I need to tighten the radios to get better bow clearance, the FB has a constant right now but I was thinking of going compound when I reshaped it.

As Nick Lloyd mentioned earlier, different players like different radii. IMO, A constant radius of about 66mm is a good compromise for both bowing and pizz playing. The constant radius will make the nut end a little flatter than with a compound radius. There is not a lot of difference, but there is some difference none the less. I doubt if you could achieve any degree of accuracy in trying to reshape it to a compound radius, so I wouldn't worry about it.

Mudfuzz · #11 05-29-2004, 04:08 PM

Thanks Bob. I'm not sure about 66 mm [I’ll have to check my notes] on this bass, that's around where I am now, if it were a four string there wouldn't be a problem, but it's a five.

Mudfuzz · #12 05-29-2004, 04:23 PM

Ok I went and checked, the radios is 67 mm. This was before dressing.

Bob Branstetter · #13 05-29-2004, 04:26 PM

Quote:

Originally Posted by A M N

Thanks Bob. I'm not sure about 66 mm [I’ll have to check my notes] on this bass, that's around where I am now, if it were a four string there wouldn't be a problem, but it's a five.

Where's Warburton when you need him! Paul and Bob Ross could give you the definitive answer on the radius for a 5 stringer. However, If I were doing a 5 stringer, I would probably want a Rhomberg bevel under the low B.

Paul Warburton · #14 05-29-2004, 05:22 PM

Quote:

Originally Posted by Bob Branstetter

Where's Warburton when you need him! Paul and Bob Ross could give you the definitive answer on the radius for a 5 stringer. However, If I were doing a 5 stringer, I would probably want a Rhomberg bevel under the low B.

Radius? What's a radius? Rhomberg? Who was Rhomberg?Sigmond...Sigmond Rhomberg...didn't he write a bunch of old tunes for Nelson Eddy and Jeanette McDonald? Bob says 70mm on the radius and no bevel.

nicklloyd · #15 05-30-2004, 11:28 AM

Thanks for the pics, Bob Standbetter. This is a very interesting and informative thread!

Hall Doorcurtain- have you seen/played on any of the Moniak (Laughing Bear Inst.) fingerboards? Does Bob Ross know of any way to get pakka fingerboards to other luthierans who don't have the big tools needed to make their own?

Mudfuzz · #16 05-30-2004, 01:53 PM

Quote:

Originally Posted by Paul Warburton

Radius? What's a radius? Rhomberg? Who was Rhomberg?Sigmond...Sigmond Rhomberg...didn't he write a bunch of old tunes for Nelson Eddy and Jeanette McDonald? Bob says 70mm on the radius and no bevel.

Ya, but at what width, I have thin neck, I'm at 67 mm and it's too flat. I'm going to try 62.5 mm.

Bob Branstetter · #17 05-30-2004, 03:04 PM

Quote:

Originally Posted by A M N

Ya, but at what width, I have thin neck, I'm at 67 mm and it's too flat. I'm going to try 62.5 mm.

OK, you lost me. What has width got to do with radius and a thin neck? And... too flat for what?

Mudfuzz · #18 05-30-2004, 03:23 PM

Quote:

Originally Posted by Bob Branstetter

OK, you lost me. What has width got to do with radius and a thin neck? And... too flat for what?

MY neck is the same width as a 4 string but it has 5 strings, that is the problem. The radius as it is with the string spacing makes the bass hard to bow cleanly, but not undoable. By making the radius smaller it should give more clearance for bowing. I might have been confusing, but then I was confused my self, sorry. For what Paul said I figured the only way to get the right clearance with a lager radius was to space the stings further apart, I know that sounds silly but that was what it made me think.

Bob Branstetter · #19 05-30-2004, 03:49 PM

Quote:

Originally Posted by A M N

MY neck is the same width as a 4 string but it has 5 strings, that is the problem. The radios as it is with the string spacing makes the bass hard to bow cleanly, but not undoable. By making the radios smaller it should give more clearance for bowing. I might have been confusing, but then I was confused my self, sorry. For what Paul said I figured the only way to get the right clearance with a lager radios was to space the stings further apart, I know that sounds silly but that was what it made me think.

The most common solution to your problem is to make the fingerboard wider than the neck so that it extends out over the B string side. Then you make the string spacing about the same as for a 4 stringer. I think you may be able to see this on the photos of Paul's Bohmann 5 string as shown on the TalkBasses (at the top of the "Basses" listing.

Paul Warburton · #20 05-30-2004, 06:13 PM

Quote:

Originally Posted by Bob Branstetter

The most common solution to your problem is to make the fingerboard wider than the neck so that it extends out over the B string side. Then you make the string spacing about the same as for a 4 stringer. I think you may be able to see this on the photos of Paul's Bohmann 5 string as shown on the TalkBasses (at the top of the "Basses" listing.

As Bob says above, use a full size board and leave the full width over on the B side to accomodate for the extra string. That way, you can keep a nice thin neck.
Also, look at Ross' 5 string cherry bass on his site. wwwrossdoublebass.com That's the one with the Pakka.
Bob Ross says Branstetter hass much more experience with the pakka than he. Ross says he's gonna try a graphite board next. Supposedly available from International Violin. He said they might be stiffer and better.