The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Build and Repair

Reply
 
Thread Tools
  #16  
Old 02-16-2017, 04:30 PM
SnowManSnow SnowManSnow is online now
Registered User
 
Join Date: Feb 2015
Posts: 411
Default

I'm asking how to get a shape for an unbent side.
I'll take that shape and cut it out of side material.
Bend the side
Then assemble with neck and tail blocks in a mold.
Then use dishes to sand them to the contour.
Sorry if I'm not being clear.
I don't have the correct lingo down yet I suppose.


Sent from my iPhone using Tapatalk Pro
Reply With Quote
  #17  
Old 02-16-2017, 05:19 PM
Rodger Knox Rodger Knox is offline
Charter Member
 
Join Date: Jul 2013
Location: Baltimore, Md.
Posts: 1,371
Default

The problem is how much work do you want to do with the radius dish?

You could leave the side full height when you bend it, but that would leave a lot of material to be removed by sanding with the dish. (or a plane or chisel)

You could also approximate the shape of the side using the neck and heel thickness, that would leave much less to be removed by sanding with the dish. I believe this is the most common method and also what you are suggesting.

Or you could use mathematics to determine the exact height of the sides at each point along its length, and then there would be no material to be removed by sanding in the dish. The problem with this method is that the sides have to be bent exactly right, and have to be perfectly "square" where they meet at the neck and heel. This is the way I do it because I don't use a simple spherical geometry for the top.
All these methods work, just different roads to the same destination.
__________________
Rodger Knox, PE
'56 Gibson J-50
et al

https://www.facebook.com/rodger.knox/photos_albums
Reply With Quote
  #18  
Old 02-16-2017, 05:41 PM
SnowManSnow SnowManSnow is online now
Registered User
 
Join Date: Feb 2015
Posts: 411
Default

So if I were to approximate the shape then use dishes would my rough diagram above be appropriate?


Sent from my iPhone using Tapatalk Pro
Reply With Quote
  #19  
Old 02-16-2017, 08:09 PM
charles Tauber charles Tauber is offline
Registered User
 
Join Date: Feb 2011
Posts: 4,580
Default

Quote:
Originally Posted by SnowManSnow View Post
So if I were to approximate the shape then use dishes would my rough diagram above be appropriate?
It sounds like you don't understand what the geometry of the unbent "developed" side looks like. It's a complex shape.

I'd suggest you put the equation into a spreadsheet like Rodger suggested, and lay it out. Then you'll better understand what shape you have and why it is that way.

Alternatively, at least for the first guitar, leave the sides un-profiled and then profile them after bending. It isn't difficult to do that way, especially if you are using spherical dishes for your curvatures. If you decide to go that route, we can walk you through that approach. It seems likely that you will save time and effort by going this route, at least for your first one, rather than spend a lot of time trying to figure out how to making templates.
Reply With Quote
  #20  
Old 02-16-2017, 08:14 PM
SnowManSnow SnowManSnow is online now
Registered User
 
Join Date: Feb 2015
Posts: 411
Default

Yea
I've built 2 kits, but this is the first time I'm trying to put together sides.
Kids come bent... as you're aware


Sent from my iPhone using Tapatalk Pro
Reply With Quote
  #21  
Old 02-16-2017, 08:15 PM
SnowManSnow SnowManSnow is online now
Registered User
 
Join Date: Feb 2015
Posts: 411
Default

Ummmm kits... although some kids may


Sent from my iPhone using Tapatalk Pro
Reply With Quote
  #22  
Old 02-16-2017, 10:51 PM
runamuck runamuck is offline
Registered User
 
Join Date: Jul 2006
Posts: 1,037
Default

Quote:
Originally Posted by SnowManSnow View Post
I'm asking how to get a shape for an unbent side.
I'll take that shape and cut it out of side material.
Bend the side
Then assemble with neck and tail blocks in a mold.
Then use dishes to sand them to the contour.
Sorry if I'm not being clear.
I don't have the correct lingo down yet I suppose.


Sent from my iPhone using Tapatalk Pro
You're being perfectly clear and I think others may be making this sound more complicated than it is.

The process you've described it exactly what I do. Just leave a tiny bit extra in the width of the sides to allow you to sand to your desired dimension.
Reply With Quote
  #23  
Old 02-16-2017, 11:15 PM
Halcyon/Tinker's Avatar
Halcyon/Tinker Halcyon/Tinker is offline
AGF Sponsor
 
Join Date: Mar 2013
Posts: 1,447
Default

I was going to let that slide...

Are the kits following any radius/taper?

Here's what I did to get my first few templates...

I used some sacrifice stock at about .060, precut very much like in your diagram (you're on the right track). I bent the fake sides then made a fake frame with ~3/16" neck and tail blocks. I made an OM frame as a middle of the road size.

I then got the radius right with the radius sanding dish, disassembled the fake frame, flattened a side on the hot pipe, (a few short minutes work at .060), then flattened it completely with an iron.

Then I decided what I wanted my final depth to be at neck and tail for the next guitar, whatever model it was, and used the OM template adjusted for depth at each end. Then I'd make a real guitar, sand it with the radius dish, make a construction paper template of the sides and adjust for depth at each end and tranfer it to 1/4" mdf, and voila, template for that model.

Grunt work, but that's mostly what this field is about.
__________________
http://www.tinkerguitars.com/
Reply With Quote
  #24  
Old 02-17-2017, 04:38 AM
clinchriver clinchriver is offline
Registered User
 
Join Date: Feb 2011
Posts: 245
Default

Quote:
Originally Posted by SnowManSnow View Post
I'm wanting to find a good plan for a 14 fret 000 OM 24.9, but I'm having difficulty locating one. I found one at LMI, but it doesn't appear to have the side shape..? Just looking for one to make some templates out of.
Any direction appreciated.
B



Sent from my iPhone using Tapatalk Pro

Not plans, Waldron Instruments makes really nice templates, tops, backs, sides,necks etc here is the OOO/OM side https://www.waldronmusic.com/product...roducts_id=448
__________________
Andersonville Tennessee
Clinch River Instruments, White Oak O, 13 fret Nick Lucas, 1937 spec D-18
Martin 000-28 EC
Gibson Les Paul
Gibson 335 Dot
Bunch of Strats
Fender B-Bender Tele
Reply With Quote
  #25  
Old 02-17-2017, 05:20 AM
hat hat is offline
Registered User
 
Join Date: Jan 2013
Posts: 514
Default

If you want a plan to work from, try this link. It has plans that you can download for 00 and OM guitars..;
http://www.grellier.fr/fr/telechargements
__________________
______________
---Tom H ---
Reply With Quote
  #26  
Old 02-17-2017, 09:29 AM
LouieAtienza LouieAtienza is offline
Registered User
 
Join Date: Feb 2013
Posts: 3,446
Default

Quote:
Originally Posted by SnowManSnow View Post
I'm asking how to get a shape for an unbent side.
I'll take that shape and cut it out of side material.
Bend the side
Then assemble with neck and tail blocks in a mold.
Then use dishes to sand them to the contour.
Sorry if I'm not being clear.
I don't have the correct lingo down yet I suppose.


Sent from my iPhone using Tapatalk Pro
Like I said, make "sides" out of Oak tag, poster board, whatever. Tape them to your mold. Mark the depths at the heel and butt. Set the whole thing down on your radius dish, and prop each side up with blocks and shims so that the marks you made are the same height off the dish. Take a scribe (a compass will work) and scribe the sides to the dish. Then take the sides off the mold and cut that line. Replace the sides and repeat to fine tune the profile. You now have an almost perfect template for the sides.

I should note I'm in the minority here and bend from the lower bout to the waist to the upper bout, where most here start from the waist...
Reply With Quote
  #27  
Old 02-17-2017, 10:26 AM
charles Tauber charles Tauber is offline
Registered User
 
Join Date: Feb 2011
Posts: 4,580
Default

Quote:
Originally Posted by LouieAtienza View Post
Like I said, make "sides" out of Oak tag, poster board, whatever. Tape them to your mold. Mark the depths at the heel and butt. Set the whole thing down on your radius dish, and prop each side up with blocks and shims so that the marks you made are the same height off the dish. Take a scribe (a compass will work) and scribe the sides to the dish. Then take the sides off the mold and cut that line.
It really is as simple as that. Simpler still, is do the same thing with your real sides, bent first.
Reply With Quote
  #28  
Old 02-17-2017, 01:28 PM
Howard Klepper's Avatar
Howard Klepper Howard Klepper is online now
AGF Sponsor
 
Join Date: May 2008
Location: Earthly Paradise of Northern California
Posts: 5,929
Default

Keep it simple:

Draw straight lines for the taper using the depth at the tail and at the neck plus about 1/4" for slop. Cut on those lines. Leave a little excess length on either end when you draw the lines, and don't trim that off until the sides are bent.

The rest will be done in your radius dish when the sides and blocks are glued together.
__________________
"Still a man hears what he wants to hear, and disregards the rest."
--Paul Simon
www.klepperguitars.com
Reply With Quote
  #29  
Old 02-17-2017, 01:40 PM
SnowManSnow SnowManSnow is online now
Registered User
 
Join Date: Feb 2015
Posts: 411
Default

Quote:
Originally Posted by Howard Klepper View Post
Keep it simple:



Draw straight lines for the taper using the depth at the tail and at the neck plus about 1/4" for slop. Cut on those lines. Leave a little excess length on either end when you draw the lines, and don't trim that off until the sides are bent.



The rest will be done in your radius dish when the sides and blocks are glued together.


Thanks Howard.



Sent from my iPhone using Tapatalk Pro
Reply With Quote
  #30  
Old 02-17-2017, 06:55 PM
Mobo Mobo is offline
Registered User
 
Join Date: May 2009
Location: Cape Breton
Posts: 23
Default

Quote:
Originally Posted by SnowManSnow View Post
I'm wanting to find a good plan for a 14 fret 000 OM 24.9, but I'm having difficulty locating one. I found one at LMI, but it doesn't appear to have the side shape..? Just looking for one to make some templates out of.
Any direction appreciated.
B



Sent from my iPhone using Tapatalk Pro
Shoot me a pm. I may have what you need.
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Build and Repair

Thread Tools



All times are GMT -6. The time now is 03:53 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright ©2000 - 2017, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=