How to make Compound Radius Fretboard???

[antontanzil]

Dear Fellows...

I look everywhere (here included) about how to make a compound radius fingerboard (radius on the nut smaller then the radius on the last fret. But I have no luck.

If anyone could help me, telling me the step by step process, not just theories, I would really-really appreciate that.

Thank you,

Anton

 

[iamlowsound]

If you have a large belt sander, it is the easiest. All you have to do is build a jig that has two arms, one for each end, at the two different radii that you want, attach the fretboard to it and swing the fretboard over the belt sander until done.

lowsound

 

[mikebpeters]

I'd love to see a pic of that one. I'm having trouble thinking through some of how it would look.

 

[jworrellbass]

You can buy one from Grizzly;

G0577 Fretboard Radius Attachment Only


I made my own and edge sander too.

 

[iamlowsound]

You can buy one from Grizzly;

G0577 Fretboard Radius Attachment Only


I made my own and edge sander too.

I was looking for that picture to post for him, but I couldn't remember who built it. I am planning on building one for doing a curved body.

lowsound

 

[knowles]

I certainly can't claim credit for this design & hope it's okay to post here.
Found this thread a little while back. Just a bit more complex but doesn't require the expensive belt sander.....
Official Luthiers Forum! • View topic - Compound Radius Router Jig For Fretboards

 

[Arsafraz]

I was looking for that picture to post for him, but I couldn't remember who built it. I am planning on building one for doing a curved body.

lowsound

This ROUTER jig is fine for "Faux" MOP, and creating Radii in WOOD, but when dealing with REAL MOP inlays already installed into the fingerboard, go ONLY with Sanding, or you could be sweeping up some rather EXPENSIVE MOP bits! That is, of course unless you live in the "rarefied" CNC stratosphere, $$$$$$$$$! I recommend the Grizzly G0577 attatchment for your 6" X 80" Edge Sander, or build your own sander as JWORRELLBASS, above did. Gb bg

 

[Bruce Johnson]

Yes, you can build a fixture rig to cut a compound radius fingerboard with a router or a belt sander. It's complicated, but it can be done. If you need to make a lot of them in production.

But, most Luthiers shape compound radius fingerboards by hand. It isn't that hard. Flat sanding blocks, radius gauges, and a straightedge.

In my case, I make lots of guitar and bass necks for Mike Lipe Guitars. Most of them are standard radius, which I cut with a router in a special fixture. But here and there, he gets an order for a compound radius neck. Mostly guitars, usually 12" to 20". In those cases, I cut the fingerboard to a straight 20" radius in the routing rig, then he hand trims it to the compound shape. It doesn't take very long for him to do that, so there hasn't been the justification to build the complex routing fixture.

Note: It's definitely easier to first cut the fingerboard to the larger (heel) radius. Then hand shape the area around the nut to the smaller radius, taking a little off the two edges, checking with a radius gauge. Then blend it all together, working with a flat sanding block and a straightedge, checking carefully along all the string paths.

 

[T_Bone_TL]

From over in DB land, The Diabolical Compund Curvature Fingerboard post.

 

[Arsafraz]

Yes, you can build a fixture rig to cut a compound radius fingerboard with a router or a belt sander. It's complicated, but it can be done. If you need to make a lot of them in production.

But, most Luthiers shape compound radius fingerboards by hand. It isn't that hard. Flat sanding blocks, radius gauges, and a straightedge.

In my case, I make lots of guitar and bass necks for Mike Lipe Guitars. Most of them are standard radius, which I cut with a router in a special fixture. But here and there, he gets an order for a compound radius neck. Mostly guitars, usually 12" to 20". In those cases, I cut the fingerboard to a straight 20" radius in the routing rig, then he hand trims it to the compound shape. It doesn't take very long for him to do that, so there hasn't been the justification to build the complex routing fixture.

Note: It's definitely easier to first cut the fingerboard to the larger (heel) radius. Then hand shape the area around the nut to the smaller radius, taking a little off the two edges, checking with a radius gauge. Then blend it all together, working with a flat sanding block and a straightedge, checking carefully along all the string paths.

Sounds like this is one way, but as far as accuracy?? The most accurate, (Level/Straight), one can make the fingerboard, the less FRET leveling, crowning, et.al. there is to put up with. As of the past few years, in following this all-important step, I now mostly just PRESS my frets in with almost NO "Drudge Factor"! I myself am ordering Grizzly's G0577 attachment, cause I've had more than enough "Drudge Factor" in my shop. Their Jig is now also selling at a reduced price than it used to be!!! Gb bg

 

[Bruce Johnson]

Hand shaping a fingerboard, whether standard or compound radius, is just as accurate as a machine, and often more accurate. Assuming that you measure and work it carefully. Use sanding blocks, radius gauges and straightedges to make it as precise as you want it. Fretless fingerboards, which have to be even more accurate, are usually rough shaped with a machine. Then we do the final truing up of the surface by hand.

Personally, I tried radiusing fingerboards with swinging fixtures on belt sanders many years ago. I tried several different setups, and gave up on them because of poor accuracy and repeatability. You have to really fuss with sanding belts to get them to cut repeatably. I went with router rigs, specialized fixtures with routers sliding on rails.

I recommend that you learn to shape the compound radius fingerboards by hand first. It really isn't hard, doesn't take long, and is very accurate (when done correctly). If that's taking too long, and you need higher production, then build yourself a good swinging router fixture rig.

 

[Arsafraz]

Hand shaping a fingerboard, whether standard or compound radius, is just as accurate as a machine, and often more accurate. Assuming that you measure and work it carefully. Use sanding blocks, radius gauges and straightedges to make it as precise as you want it. Fretless fingerboards, which have to be even more accurate, are usually rough shaped with a machine. Then we do the final truing up of the surface by hand.

Personally, I tried radiusing fingerboards with swinging fixtures on belt sanders many years ago. I tried several different setups, and gave up on them because of poor accuracy and repeatability. You have to really fuss with sanding belts to get them to cut repeatably. I went with router rigs, specialized fixtures with routers sliding on rails.

I recommend that you learn to shape the compound radius fingerboards by hand first. It really isn't hard, doesn't take long, and is very accurate (when done correctly). If that's taking too long, and you need higher production, then build yourself a good swinging router fixture rig.

Thanx, I designed,and built a great, (and accurate) swinging Jig over 20 years ago that worked out fine, tracking on rails as well. I wanted to simply track my router down the center of the swing axis, and cut by swinging the fingerboard side to side, but "WHADDAYANO", that method produced 'tear-out', so I had to instead, swing, and then CLAMP the jig in small degree increments, and then track the router as mentioned which produced a splendid result that needed only minor hand sanding to remove what little tooling marks were left behind. I say all this to point out that while this machine worked well on PLASTIC inlaid position markers, I am now dealing with TOP quality MOP slabs, @ .09 thickness. If you are familiar with, (you probably are!) the Rickenbacker style inlays, then you know they butt up to the neck bindings on both sides, hence the need for thicker MOP to accommodate almost any Board Radius W/O the risk of being sanded away at the ends. The "SIX" pieces my customer purchased, which should be enough for TWO boards, ( if I am extremely frugal) cost $80.00, incl shipping. Having never worked with MOP in this fashion, and having done a fair amt. or research on the process, I see that most folks, with $$ to burn) are using CNC machines, at controlled speeds/feeds, and taking SMALL .006 to .010 depths of cut to cut the inlays. I've made a good routing template for the pockets/recesses that was SUPPOSED to be used to cut both Inlay shapes as well as the recesses using a MLCS Brass Inlay routing Bushing kit, with which one first uses the large removable bushing at .5625 Dia. (actual) to rout the recesses, and then removing that to rout the periphery of the inlays. In short, I'M SCARED!!! So, I've decided to go in reverse, by FIRST routing the recesses with my good template, then applying "GRUNTS", (classic, saw out/File/Sand, custom fit each one) to shape the inlays. Now, after putting myself through all that "Rigamarole" I'd rather not destroy all that, by tracking a Router bit over them while Radiusing the Fingerboard! So, am I needlessly "fretting", so to speak, or am I correct in assuming that the Sanding approach might not create the "Shrapnel" I'm afraid of creating? The saddest part of all this is that using the REAL MOP was MY idea in the first place!! ({TRE%DFHJ<%^$&()GHKJNMRE^E%*(*(_R^TY!!!!!!!! Help! PS: I'm a retired CNC Programmer/Machinist who dearly misses the opportunities in the past to do projects like this, "under-cover", if ya know what I mean? Now on S.S.I. I can't even afford the Desktop "Bots" available!! Gb bg

 

[Bruce Johnson]

Yes, if you use a router to cut MOP, you have to use a sharp bit and take light passes. Whether in a router fixture or by CNC.

Sanding MOP isn't likely to chip it, but you have to deal with heat. Because it's much harder, the sanding belt will cut the MOP slower than the wood surrounding it. It will end up higher than the wood around it, and get hot quickly. This can make it distort or come unglued. As with the router, you have to sand slowly with light pressure.

There isn't any good answer. MOP is basically a piece of stone. The best and safest way to surface it is gently, by hand, with a file.

Personally, I gave up on using real MOP for dots and inlays a long time ago. Too many technical hassles, legal hassles, cost. Not worth it. I use the synthetic pearl material from Masecraft. It's about the same hardness as the surrounding wood; it machines and polishes up beautifully. And in most cases, it's actually better looking than the real thing.

 

[Arsafraz]

Yes, if you use a router to cut MOP, you have to use a sharp bit and take light passes. Whether in a router fixture or by CNC.

Sanding MOP isn't likely to chip it, but you have to deal with heat. Because it's much harder, the sanding belt will cut the MOP slower than the wood surrounding it. It will end up higher than the wood around it, and get hot quickly. This can make it distort or come unglued. As with the router, you have to sand slowly with light pressure.

There isn't any good answer. MOP is basically a piece of stone. The best and safest way to surface it is gently, by hand, with a file.

Personally, I gave up on using real MOP for dots and inlays a long time ago. Too many technical hassles, legal hassles, cost. Not worth it. I use the synthetic pearl material from Masecraft. It's about the same hardness as the surrounding wood; it machines and polishes up beautifully. And in most cases, it's actually better looking than the real thing.

Thanx Bruce, I've come to the same collision, (conclusion, Ha!)! I'm just gonna tell my customer who, thank the Lord, happens to also be a friend, (Phew), that I'm throwing in the Towel on this "MOP-UP", and knocking the $80.00 off my labor charge. I'm on my way to check out Masecraft, per your gracious suggestion, and I can't thank you enough my friend. When you said:"MOP is basically a piece of STONE", that immediately put every thing in the proper perspective!!! . Gb bg PS: does the Faux plastic MOP come in a .09 to .1 thickness? Thanx again!

 

[Arsafraz]

Thanx Bruce, I've come to the same collision, (conclusion, Ha!)! I'm just gonna tell my customer who, thank the Lord, happens to also be a friend, (Phew), that I'm throwing in the Towel on this "MOP-UP", and knocking the $80.00 off my labor charge. I'm on my way to check out Masecraft, per your gracious suggestion, and I can't thank you enough my friend. When you said:"MOP is basically a piece of STONE", that immediately put every thing in the proper perspective!!! . Gb bg PS: does the Faux plastic MOP come in a .09 to .1 thickness? Thanx again!

 

[Arsafraz]

Hey Bruce, Can't seem to find the SYNTHETIC you mentioned, just laminated MOP?

 

[Arsafraz]

Yes, if you use a router to cut MOP, you have to use a sharp bit and take light passes. Whether in a router fixture or by CNC.

Sanding MOP isn't likely to chip it, but you have to deal with heat. Because it's much harder, the sanding belt will cut the MOP slower than the wood surrounding it. It will end up higher than the wood around it, and get hot quickly. This can make it distort or come unglued. As with the router, you have to sand slowly with light pressure.

There isn't any good answer. MOP is basically a piece of stone. The best and safest way to surface it is gently, by hand, with a file.

Personally, I gave up on using real MOP for dots and inlays a long time ago. Too many technical hassles, legal hassles, cost. Not worth it. I use the synthetic pearl material from Masecraft. It's about the same hardness as the surrounding wood; it machines and polishes up beautifully. And in most cases, it's actually better looking than the real thing.

Hey Bruce, I can't find the stuff on Masecraft that you mentioned??? Only laminated MOP!

 

[Bruce Johnson]

Hey Bruce, I can't find the stuff on Masecraft that you mentioned??? Only laminated MOP!

Look under Polyester Pearl Sheets:

Polyester Pearl Sheets

This is what I use for all my "pearl" dots and inlays:

Invalid Link Removed

 

[Arsafraz]

Look under Polyester Pearl Sheets:

Polyester Pearl Sheets

This is what I use for all my "pearl" dots and inlays:

Invalid Link Removed

WOW Bruce!!!!! Most excellent. If splitting the .250 material with a sharp .04 kerf band saw blade, will the material "Dish"? I'd be up for splitting rather than routing off and wasting around .150 material! Too bad they don't come in .125 thickness for "us" (picky, picky, Ha!! I agree with you, that if this stuff finishes up like the Pics., it will be very "striking"! drool Thanx again. Gb bg

 

[Bruce Johnson]

Masecraft's Polyester Pearl is a nice moderately soft plastic. You can easily saw it. It's fairly flexible, not brittle. You can clamp it down to a curved surface without breaking it.

The cool thing about the appearance is that it's more transparent than real pearl. The 3-D sparkly swirls have depth when you look down into them. You can paint the back side of the inlays before gluing them in, for more dramatic color effects. Black, silver, gold, purple, whatever you like.