Official Luthiers Forum! :: View topic

28' radius for everything but the UTB (60') gives me a 1.5 degree neck angle and 1/2" string height at the saddle. I don't have a 60' dish - i just glue in the 60' radius UTB on a flat surface and it ends up giving me what I want.

backs on Martin dreds start at 20 foot radius and 000 at 15. Also a note is once they are glued they tend to change a bit from RH. As for the top there is a slight radius and a 1 1/2 degree incorporated to the top. As a repair center for Martin I was invited to go to the CF Martin repair summit last year and this is the equipment that they use .
I was allowed pictures and to study this . It is quite the machine. I wish I had one.

Attachments:

P8010027 (Small).JPG [ 53.5 KiB | Viewed 3 times ]

P8010026 (Small).JPG [ 49.98 KiB | Viewed 3 times ]

Thanks guys. I think I will go with a 28' for the top and 15' for the back for now. Has anyone bough radius dishes from Luthier Suppliers? http://www.luthiersuppliers.com/products/p4.html It seems like their dishes are well made and fairly priced.

Author:	Goodin [ Wed Mar 14, 2012 10:55 am ]
Post subject:	Radius Dishes
I am in the market for radius dishes and I am a bit confused, or I guess I should say uneducated about them. Stew Mac sells the following: 15-foot radius for Martin backs 20-foot radius for modern guitar backs 28-foot radius for modern guitar soundboards 40-foot radius for Martin soundboards I am curious why the change in radius for modern guitar versus Martin. Does this change in radius really make a difference in tone and structural integrity? I am planning on building my first guitars closely based on Martin guitars so should I go ahead and get the Martin radii or is it better to get the modern radii? Any suggestions on a few all around radii to get? These things are expenses so I'm hoping I can get just one for the top and one for the back. Thanks for any advice.

Author:	stan thomison [ Wed Mar 14, 2012 11:07 am ]
Post subject:	Re: Radius Dishes
Either way. I guess if wanting to stay true to Martin and that is their standard then do that. My dishes range from 60ft to 24 ft on the top and 30 ft to 15 on the back. You can have what you want. If just starting then suggest stay with those by Stew Mac No reason for that other than they are proven for quality sound over the years. Once you have done some guitars and want to check out others then go for it.

Author:	Tai Fu [ Wed Mar 14, 2012 12:46 pm ]
Post subject:	Re: Radius Dishes
For the dish with smaller radius such as 25' which I have been using, I found serious issue with gaps under the fretboard unless a very high neck angle is used. I had to shim the fingerboard in order to make the gap disappear. So that's a reason for me to use a flatter radius for the top.

Author:	Bryan Bear [ Wed Mar 14, 2012 3:02 pm ]
Post subject:	Re: Radius Dishes
Todd Stock wrote: 28' radius for everything but the UTB (60') gives me a 1.5 degree neck angle and 1/2" string height at the saddle. I don't have a 60' dish - i just glue in the 60' radius UTB on a flat surface and it ends up giving me what I want. Todd, do you flatten the rim north of the waist to match the flatter upper bout or do you just sand the whole rim to 28' and get what you want from the flatter brace?

Author:	dberkowitz [ Wed Mar 14, 2012 3:38 pm ]
Post subject:	Re: Radius Dishes
Martin backs are not 15'. Closer to 20'

Official Luthiers Forum! http://www.luthiersforum.com/forum/

Radius Dishes http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=35770	Page 1 of 1

Author:	bluescreek [ Wed Mar 14, 2012 4:30 pm ]
Post subject:	Re: Radius Dishes
The radius has little to do with tone. I culled my disk inventory to 28 for top and 15 for all backs. the key for the top is to match the neck angle so you have a flat and true fretboard plane with about 1/2 inch string height at the top .

Author:	Tim L [ Wed Mar 14, 2012 9:40 pm ]
Post subject:	Re: Radius Dishes
You got me on that one Todd. Are you saying that the back on the D and M are a 25' radius? And going how far back in time? Especially since their tops are so flat also. I use 20' for my 000/OMs. Wish John Arnold would add on this as I remember he and Willie Henkes talked about a compound radius on the backs of older Martins. Meaning that it was different longitudally than across the back and they were braced up in fixtures rather than dishes. Somewhere on the UMGF there will be a thread showing pix of the fixtures and more discussion. Tim

Author:	Joe Sallis [ Thu Mar 15, 2012 4:41 am ]
Post subject:	Re: Radius Dishes
I'm about to use the Grellier plans to build an OM. The plans have a 25' radius on top. If I used a 28' radius would I have to change the bracing at all? I could then use Todd's method of the 60' UTB.

Author:	Mattia Valente [ Thu Mar 15, 2012 6:41 am ]
Post subject:	Re: Radius Dishes
No need to change the bracing plan based on a 3 foot difference (which is almost nothing over the span of a brace) in radius.

Author:	bluescreek [ Thu Mar 15, 2012 7:24 am ]
Post subject:	Re: Radius Dishes
backs on Martin dreds start at 20 foot radius and 000 at 15. Also a note is once they are glued they tend to change a bit from RH. As for the top there is a slight radius and a 1 1/2 degree incorporated to the top. As a repair center for Martin I was invited to go to the CF Martin repair summit last year and this is the equipment that they use . I was allowed pictures and to study this . It is quite the machine. I wish I had one.

Author:	Robbie_McD [ Thu Mar 15, 2012 8:13 am ]
Post subject:	Re: Radius Dishes
^^^ Nice!!!! Beats the crap out of "driving the bus", right John?

Author:	Goodin [ Thu Mar 15, 2012 8:13 am ]
Post subject:	Re: Radius Dishes
Thanks guys. I think I will go with a 28' for the top and 15' for the back for now. Has anyone bough radius dishes from Luthier Suppliers? http://www.luthiersuppliers.com/products/p4.html It seems like their dishes are well made and fairly priced.

Author:	Tim L [ Thu Mar 15, 2012 8:40 am ]
Post subject:	Re: Radius Dishes
Quote: backs on Martin dreds start at 20 foot radius and 000 at 15. Also a note is once they are glued they tend to change a bit from RH. As for the top there is a slight radius and a 1 1/2 degree incorporated to the top. As a repair center for Martin I was invited to go to the CF Martin repair summit last year and this is the equipment that they use . I was allowed pictures and to study this . It is quite the machine. I wish I had one. Attachments: P8010027 (Small).JPG [ 53.5 KiB \| Viewed 3 times ] P8010026 (Small).JPG [ 49.98 KiB \| Viewed 3 times ] John, are those holding fixtures pneumatically actuated? That's pretty cool, although only making a couple guitars a year think I can still hold mine by hand. Tim

Author:	bluescreek [ Thu Mar 15, 2012 3:42 pm ]
Post subject:	Re: Radius Dishes
there are pneumatic cylinders there so I think so. It is a nice chunk of engineering

Page 1 of 1	All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/

Author:	James Orr [ Thu Mar 15, 2012 4:42 pm ]
Post subject:	Re: Radius Dishes
Goodin wrote: Thanks guys. I think I will go with a 28' for the top and 15' for the back for now. Has anyone bough radius dishes from Luthier Suppliers? http://www.luthiersuppliers.com/products/p4.html It seems like their dishes are well made and fairly priced. I just ordered a set yesterday Good stuff. Tracy made my first few as well.