Luthier Tips du Jour Mailbag 107 - Compound radius

Luthier and Instructor, Robert O'Brien, shows how to put a compound radius on a fretboard.
www.obrienguitars.com ‍
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[@HoffOfAllThings]

Years ago I took your first class at red rocks community college for classical guitar building. It's pretty awesome that I can get on KZbin and still learn from the master. Still, my favorite hobby, although I haven't built a classical since. Thanks for the lifelong gift. Oh, and "Just a scoche" has been forever adopted into my vernacular since that class.

[@OBrienGuitars]

That sure was along time ago! Glad to hear you are still finding my information useful.

[@basdieleman9998]

"That usually happens right before your arm falls off" I can`t stop laughing!

[@jeffdevries5044]

Thank you for this. Very good and helpful. Chalk is a great idea for a visual reference, I have often used pencil which is harder to see. I totally understand the “until your arms fall off” statement! Thanks again.

[@bonebibleviper]

My Treadmill “belt sander” stopped working half way though my current build and this was very helpful. thanks again.

[@skunkygrogan4247]

Thx Robbie. That was a good one.

[@guitarraesporrenta]

Obrigado pela dica Robert! Happy new year!

[@OBrienGuitars]

obrigado e para voce tambem.

[@obijuano]

Awesome! Thank you. I've been wanting a video like this using just the sanding blocks for the compound radius.

[@edwardr.4605]

Thank you!! Awesome video.

[@bonebibleviper]

Thanks for the tip man

[@GerryBlue]

This is really useful, thanks!

[@AudioAtmos]

Very nice and concise. Thanks! And pink IS very mid-rangey.😁

[@aaronmaiden3606]

Thanks for the video!

[@OBrienGuitars]

Thank you for watching. Glad you found the video useful.

[@walterrider9600]

thank you

[@UrquidiGuitars]

Robbie, thank you very much, I just did a Charvel neck 10"-12"-16" this was very helpful. So far so good.

[@OBrienGuitars]

Glad you found the video useful. Thanks for watching.

[@Stu66orn]

Great video thank you

[@robertnewell5057]

Thanks, Robbie. I don't do compound radii, as I work exclusvely on acoustics and have never felt the need, BUT, this is the clearest, briefest explanation I have ever seen of the rationale for compound radii and how to acheive them without complex jigs, etc.

[@MoGiMaL]

Conical radiuses are good for acoustics too, they help you get the action lower.

[@robertnewell5057]

@@MoGiMaL That's interesting. I must admit I haven't struggled getting low actions, but I can see how your suggestion would apply

[@samuelbelschner5124]

Thanks for this Tipp

[@Emiroj]

This was a great tutorial man! Now I feel confident about doing this to my les paul. I don't like the 12" radius across the whole fingerboard and comparing to other guitars I have with 16-17" radius closest to the neck pickup, they are more easy to play on, so I hope this will be an improvement and then I'll also do a refret job. I'm more comfortable with refretting guitars than sanding the radius, but I'll try on a scrap piece of wood first so I don't ruin anything! Greatings from Sweden!

[@OBrienGuitars]

Thanks for watching. Glad you found my video useful. Cheers, from Colorado

[@paulobussad16]

Muito Bom Obrien! Estou ansioso para testar este método aqui na Bussad Luthieria. Obrigado por compartilhar seu conhecimento conosco! Grande abraço de um fã aqui no Brasil.

[@KARANARJUNMUSIC]

I loved your video. Just wanted to ask, I want to do this for my own build. I want 10 inch till say the 5th fret and and 16 inch from 8th to 22nd. Basically I want the majority of my fingerboard to be flat, but still have the ability to play the cow boy chords with ease. Can I do it in that fashion, rather than 3 equal parts of 10, 14 and 16?

[@natanborges5983]

Meu amigo sou fã do seu trabalho, sonho um dia ser igual a você

[@OBrienGuitars]

Muito obrigado e tudo de bom para voce em 2020

[@themixmusicandmore6280]

What about leveling the actual frets on a compound radius fretboard?

This task is ideal for a cnc router - far cleaner and more accurate! Keep the sanding blocks for glue cauls, fret press cauls, or make a matching cr caul on the cnc!

[@molekyyli]

You're lucky if you have access to that but many of us don't... Gonna have to do it by hand since I don't wanna give up putting a Floyd and can't find a suitable locking nut in other than 10'' radius. And I definitely don't want a 10'' fretboard.

[@Generalvass]

Gostei.

[@OBrienGuitars]

ainda bem!! hehe

[@k_aos3224]

Hi Robert! Thanx so much for this easy to follow tutorial on the compund radius! Quick question, though, since I couldn't see it clear enough on screen: was the leveling bar really level or did it have a curved contour on the sanding surface? it looked to me like a level square profiled aluminum bar ... thanx so much for your help in advance and best regards from Germany! Kevin

[@OBrienGuitars]

It is indeed a flat and level bar. Hope this helps and Happy Building!

[@lucaormas2073]

hello to level the keys on a compound keyboard do you use a long bar or pads?

[@OBrienGuitars]

I use a long bar.

[@billiramone]

Hey Man! Any tips on how to set up a guitar with compound radius?

[@OBrienGuitars]

Set it up like you would normally set up a guitar.

[@rebelartwork]

How do you level frets on a compound radius? Same technique as when you blended?

[@OBrienGuitars]

You got it. Just use a leveling bar and sand in a conical shape as you level. Michael Bashkin has a great fretting course that covers this. obrienguitars.com/courses/bashkin-fretwork

[@joeking433]

I thin multi-radius necks should be left to the CNC machine.

[@TheGreasemonkey220]

Quick question, how do you do a fret level on a compound? I have done many fret levels on guitars I've build but all of them a standard style single radius. I currently have a guitar with some problem frets throughout which causes issue with string height but has a compound radius. I take it just run my leveling beam as shown for the fret board leveling just transferred over to fret leveling?

[@OBrienGuitars]

You level the frets using the same method you used to put the compound radius in the fretboard. Michael Bashkin explains this thoroughly in his Fretwork course available here. obrienguitars.com/courses/bashkin-fretwork

[@TheGreasemonkey220]

@@OBrienGuitars fantastic i greatly appreciate it!

[@grahamjenkin2882]

Great tips, as always. I'm guessing the pink chalk came from lmi......😀

[@OBrienGuitars]

Actually the chalk came from my local lutherie supply warehouse

[@madgeniusmusic]

Great video as always, thanks, Robbie. How's 2016 treating you?

[@OBrienGuitars]

haha. I made the video in 2016 and only released it now. I have a queue of videos ready to be released several years long. You will be hearing from me for years in the future, even if I stop making videos.

[@madgeniusmusic]

OBrienGuitars good to know, but don’t stop, ok?

[@italianguitargarage708]

Hello Robbie, when I do radius with blocks as you have, I usually have a perfect radius in the middle untill the edge where usually I see a bit of light, and it really bother me cause I can’t get rid of that defect and it also affect the fretting a bit. Also I see that usually this don’t happen while using high grit but only when switching to finer grit (like 120 or more). Do I do something wrong? Cause I use pro tool and don’t think they’re wrongly machined.

[@OBrienGuitars]

Well, it could a few things. Are you wrapping a piece of sandpaper on the block? Sometimes there is a ripple in the paper and it can round over the edges a bit.

[@italianguitargarage708]

@@OBrienGuitars I usually cut 2 stripe of double-sided tape and stick em at both end of the block, then attach the sandpaper on (and perfectly trimming it around). I also have a solid sustain under the neck to not let it bow with the pressure

[@italianguitargarage708]

I'm 75% sure I do something wrong, like ''sanding method' because that thing happen in every neck I do. I changed the way I attach sandpaper to the block just to verify but it still happen. I sometimes can't understand how much force to put into block while sanding. and I have the small impression that if I press too much it 'eat' over the edges, and if I don't press enough it don't 'eat' in the centerm so I'm always uncertain on what to do

[@OBrienGuitars]

@@italianguitargarage708 Well, it is hard for me to diagnose without seeing your process. Would a long sanding bar like I show in the video remedy the problem?

[@jdy5556]

If you aren't keeping the block perfectly straight (i.e. twisting it when viewed from above) it can cause this type of problem. I made a three sided trough that guides the radius block and prevents any unwanted movement. The guide needs to be fairly low to allow you to grip the block or you can add a handle to the block as I did.

[@steveassante6797]

This is slightly off subject, but do you know if it is Charles Fox who's in charge of LMI these days ? Charles is an Artistic, Creative guy who used many of the Luthier jigs that LMI now carry ! (Sorry for the interuption)

[@cornbobrimlove7892]

Charles in charge.......

[@GTguitarworks]

Hi, Question? If you do the 14 inch first, then come in later to do the heavier radiuses, don’t you take a chance at the fretboard ending up being thinner down at the nut end Area and thicker up at the tongue? I understand you came in with the leveling bar later to make sure that you are level, however you can still be level on the surface and be thinner as a nut and thicker at the tongue. Which would defeat having fall away?

[@OBrienGuitars]

I guess this could happen but you are doing minimal sanding. The sanding bar blends everything together.

[@GTguitarworks]

OBrienGuitars Hi thanks for your fast response. would it be safer to do The 10” first the 12”, 14” then the leveling bar. Or would that take too much off? Thanks again 👍🎸👍

[@OBrienGuitars]

@@GTguitarworks No. that would also work. Just find the way that best suits your needs and go with that. I think either way would work.

[@xavierbaron6454]

@@GTguitarworks If you proceed that way your fretboard WILL be thinner where it is 14" radiused

[@GTguitarworks]

Xavier BARON That’s the idea I wanna create a little fall away

[@davidthompson6832]

Same method for leveling frets,right? Because of compound radius...???HELP!!!

[@OBrienGuitars]

yes.

[@walt5797]

Forgive me for asking this as I'm not a luthier's bum. But, Wouldn't it make more sense to do the smaller radius first to maintain an even fret board edge thickness?

[@OBrienGuitars]

I suppose that would also work but I have never tried it that way.

[@har234908234]

I would go the other way... establish a uniform thickness for the entire fretboard edge, then flatten the body end. In any case the real money is getting the frets leveled and dressed right. I did calculate what the sagitta difference would be once and it wasn't much - something like 0.5mm difference... but don't quote me!

[@OBrienGuitars]

That is also a way to do it. I like it.

[@pallecla]

Take a drink each time he says LMI :-)

[@scherzo0o]

being sober sucks anyway :)

[@TheMenap]

How many languages ​​do you know?

[@OBrienGuitars]

fluent in Spanish and Portuguese and I get by in Spanish.

[@Dreamdancer11]

Levelling bar is not from Lmi....i stopped watching right there....

[@charleskirton3552]

Great Video Thanks

[@OBrienGuitars]

Glad it was helpful!