Official Luthiers Forum!

Hello everyone,

I am going to order plans for this OM model http://www.lmii.com/products/media-gifts-more/plans/plans-steel-string/951-plan-orchestral-model-similar-to-martin-om/flypage-noimage

What size radius dishes would you recommend?

Hi Jonathan: I've built a lot of OMs with a 15' back radius and a 25' top radius. Another option that I always wanted to try was a 28' radius for the top. Nice thing about the 15/25/28 radius for building is that you can build lots of shapes and sizes with these dishes as well.

Thanks Hesh. When I built the body of my first guitar a few years ago I thought 15 was what I used on the back, but I wasn't sure about the rest. I am about to order a set so i thought I would double check first.

On another note, are there any lesser known shops that I am not aware of who might sell these? Everywhere I look they run around $70-80.

Hey Jonathan,

I sell radius dishes, and with the US dollar being stronger than the Canadian dollar right now you would save around 20% of my listed Canadian prices. That drops the price of my 24" dishes bellow $70 USD. I also offer discounts if you order 2 at a time. Shipping is reasonable. If you are interested PM me with what you are considering and I can give you a detailed quote.

http://www.canadianluthiersupply.com/collections/radius-dishes-work-boards

15' and 28' are the most popular sizes I sell, and as Hesh said work well for a variety of shapes.

_________________
Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

double post

_________________
Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

I use 15 and 28
https://www.youtube.com/watch?v=pz6xzVRA51E
Note that the purpose of the top is to establish the angle
https://www.youtube.com/watch?v=TXfyVb3L3G0
watch both vids it will make it clear on what you need to do. If you don't get the geometry right your guitar will never reach its full potential. Think of it this way , the body coverts the strings to work the neck makes it play and if you mate them right you get a great guitar.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I started using flat radius on the top... I had serious problem with 25/28 foot radius for the top because I would get ugly gaps at the fingerboard unless I used a very high neck angle. So I would radius the X braces with a 25 foot radius dish and then make the rim flat.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

15' 28' and 15' 25' are our best selling combos. Martin uses 15' back braces and 52' top braces on their high line models, the top edge of the rim is sanded flat (no bevel) with a 1.3 degree slope from sound hole to neck block. As mentioned matching the neck and sound board with complimentary angles is a critical step. Of course there are many ways to get the top edge sloped correctly, our recommended method is described here:

http://www.kennethmichaelguitars.com/ri ... angle.html

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

The point that Ken brings out is valid , if you don't get the fret plane correct and create the height at the point of the bridge you are just gluing things together. If you don't take the time to prep this in the rims and bracing you will never get it right.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I use 15/28 as well

_________________
Blue Ring Acoustics
blueringacoustics.ca

Thanks Ken. Come to think of it I may have ordered my last dishes from you several years ago. I built the box last time, but gave it away to another builder since I didn't have the time or energy to finish my build, so I never got to the neck or fingerboard issues described. Good to know!

Yup, a guy has to have a plan to get the alignment spot on .
I use 15/25.
The 25' for the top works perfectly for me as I have followed Mr. Hesh's excellent and foolproof tutorial on flattening the upper bout for the last 5 years or so.
Generally speaking, when fitting the neck you are looking for 2.5mm airspace over the bridge location when running a straightedge over the beck (without fretboard)
25' radius and flattening the upper bout gets me there every time...

Rob