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Hello everyone. I'm a new " guitar builder " from the Netherlands, trying to make my first steel string. I'm a member for almost one year and i've learned a lot from all of you.
But i've a question about the radius disk. I was wondering when i use a radius disk, were is the center of the radius disk according to the guitar top ? I hope i make myself clear, because i'm not use to write in English.

Greetings from the Netherlands,

Cees Swiers

Although there is no hard and fast rules, most steel string guitar tops are radiused 15ft (center pointing in towards the body of the guitar, of course).

I hope that answers your question.

If you get a ply dish, the center will be seen, I drill a hole in the center to mount it. Technically your sanding inside a sphere, so the center is any area on the dish. Just eyeballing should do it.

Alot of builders have gone to a 28' or 30' dish for the top, backs are usually 15'

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Welcome out of lurkdome Cees

Actually, most tops are made with a 25' or larger radius.

There is no center as you're talking about the the surface of a sphere. What I think you are asking is, where is the high point. That will be at the middle point of the top (if the body is 20" long, than at 10") and on the center line.

This is assuming you don't sand one end (head block end or tail end) down further than the other.

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Hi Cees, welcome to the OLF!

What Rod said.

Chuck

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Hi Cees and welcome to the OLF!

Rod is right as usual - anywhere inside the radius dish will have the same radius. For our purposes we do try to center things in the dish but only for reasons of support - the dish, if properly made will have the same radius at any location.

Welcome aboard!

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Just be sure to measure the left and right halves of the guitar during the process to make sure that you are radiusing the body evenly. Otherwise you'll have to ask Linda Manzer for permission to use her wedge shaped body design.

Oh, and welcome to the group.

By the way if you're buying radius dishes I understand that shipping from the US is going to be really steep unless you have a European supplier that will sell you radius dishes. So what I did (I live in Taiwan.. more likely that there will be luthier suppliers in Europe than in Asia) is buy one 25' dish and use that for back and top. Shipping is still expensive but at least not overkill. I then took several sheets of 80 grit sanding cloth and glued it to the dish with rubber cement. Total cost of the sandpaper is only 1 dollars, compared to 20-30 dollars for sandpaper big enough! I just hope I can remove it without damage to the dish if I need to...

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You might want to send a private message to OLFer Mattia Valente...

He lives in the Netherlands and might be able to help you out with advice.

Yes, right. I meant 25'

That is the worst thing to do, give an answer and be careless about it. I apologize.

Thank you all for the response.
Yes, what i was trying to say is where the high point is. I was thinking that should be where the bridge is, because of the neck angle. And using the radius disk for sanding the sides, there will be no contact with the waist, so the sides at that point must be flat ??

By the way, i'm using the "Campiano Guitarmaking Book" and the "Jonathan Kinkead Book" and they do noy talk about using a radius disk.

I will try to make my one radius disk. I saw a very good tutorial on the youtube.
http://www.youtube.com/watch?v=tvGemvizrz4

Cees

I used the method Chris shows in the video to make some dishes. It worked very well once I had things set up.

John

Cees,

Welcome to the OLF! Where in the Netherlands are you from?
It is quite an amazing country. I had the privilege of spending a couple weeks there in 2006 and fell in love with the place...

Stephen

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Cees,

Most people who use a sanding disk/dish will sand till every surface of the edge is sanded. That means right into the waist too. So the entire edge is profiled to the 25' radius sphere.

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