PL29 Parlor

[Zen]

Rusty,
when I make up my blocks I do 92 degrees for the tail block top and back angles, and 92 and 96 degrees for the top and back angles of the headblock, respectively. this just gets you in the ball park and everything is set to level out after the kerfing is on, with your radius dish/bar or what-have-you.

Thanks for that Darren , I should be up and running as soon as I get my head around that but I'm not a woodworker and will have to do some research on degrees and angles.
But I really appreciate your trying to help me so thanks again
Regards
Rusty

[Zen]

Just checked the height of the neck block and its 85mm as it stands.

[Kevin Sjostrand]

Rusty,
I suggest you get Bill Cory's book which has alot of great information building a kit guitar. He is the person who started this forum and ran it for a number of years before John Hall took it over.
Bill has a sale right now on the ebook form of his book - http://www.kitguitarmanuals.com/
You can also get the real book. It will help explain a lot of the steps in assembling your guitar kit, you won't be disatisfied.
There is no magic to configuring your neck and end blocks. Get Bill's book.

You could also get Robbie O'briens dvd from LMI on building a steel string guitar. He builds an OM, but the principles are going to be the same, then you pretty much just follow your plans.

We will all try and help as much as we can, but having it it writing and pictures will be a big help to you.

Kevin

[Zen]

Did you build exactly exactly in accordance with the PL29 Plan ?

Rusty, the maple one was built very close to the plans but with .25" (that's a skosh over 6mm.. :) ) tapered bracing top and back. And the longer scale which was recommended to me by another builder. Antes is well known for 'over-bracing' his plans.

BTW, my first guitar was an LMI 'kit' (and an unserviced one at that, basically a box of wood) and would agree that the puchasing from LMI sure does provide 'the deepest' building experience, but you've got to read, re-read and ask lots of questions. I would not have succeeded in even the basic woodworking operations had it not been for this forum.

When Darren says he built it using 6mm tapering --how do I work that out ? I know I need to learn these things for myself if I'm going to keep building but any advise would be much appreciated
Rusty

[Zen]

Same question again as in last post if anyone can contribute please ?



And also have a new one: How do i figure out a 52 ft radius ? Thats what I've been advised to do with the braces, as Martin guitars use that to prevent a concave appearance and only slightly radius or contour their braces.

[johnnparchem]

Here is a link to a page that shows how to calculate the sagittal of an arc. http://liutaiomottola.com/formulae/sag.htm

I would get a thin flexible rod around 18" to 2 feet, drive a couple of brads a couple of inches less apart than the rod is long in a board that you can cut to be you 52ft radius. draw a line between the two brads. Calculate the sagitta (sag) for a arc the length of you rod with a 52 ft radius. Right in the center of the line you drew drive another brad the calculated sagitta up from the line.

Take your flexible rod and have the end brads over and the center brad under the rod. The curve will be your 52' radius. Draw it and cut it and you will have a 52' radius guide.

[Zen]

Here is a link to a page that shows how to calculate the sagittal of an arc. http://liutaiomottola.com/formulae/sag.htm

I would get a thin flexible rod around 18" to 2 feet, drive a couple of brads a couple of inches less apart than the rod is long in a board that you can cut to be you 52ft radius. draw a line between the two brads. Calculate the sagitta (sag) for a arc the length of you rod with a 52 ft radius. Right in the center of the line you drew drive another brad the calculated sagitta up from the line.

Take your flexible rod and have the end brads over and the center brad under the rod. The curve will be your 52' radius. Draw it and cut it and you will have a 52' radius guide.

Thanks, thats the first time I saw the Over and Under the rod mentioned, I wonder if everyone is aware of that ? Its occurred to me that I may have calculated my last radius wrongly as I had the rod in front of the two end brads-on the 1/16th side or whatever its meant to be-- and in front of the middle brad as well----hmmmmm.
Thanks for the tip
Rusty

[johnnparchem]

Here is a link to a page that shows how to calculate the sagittal of an arc. http://liutaiomottola.com/formulae/sag.htm

I would get a thin flexible rod around 18" to 2 feet, drive a couple of brads a couple of inches less apart than the rod is long in a board that you can cut to be you 52ft radius. draw a line between the two brads. Calculate the sagitta (sag) for a arc the length of you rod with a 52 ft radius. Right in the center of the line you drew drive another brad the calculated sagitta up from the line.

Take your flexible rod and have the end brads over and the center brad under the rod. The curve will be your 52' radius. Draw it and cut it and you will have a 52' radius guide.

Thanks, thats the first time I saw the Over and Under the rod mentioned, I wonder if everyone is aware of that ? Its occurred to me that I may have calculated my last radius wrongly as I had the rod in front of the two end brads-on the 1/16th side or whatever its meant to be-- and in front of the middle brad as well----hmmmmm.
Thanks for the tip
Rusty

I am not sure you did anything wrong last time. The over under just let's the rod stay place. You way maybe more accurate.

[ruby@magpage.com]

Rusty:
A couple of months ago I posted an easy method of drawing an arc of a circle. The method with the bent batten mentioned above will get you close, but will not be a true arc.

Go to "building tools" and look on page 2. A few down is the topic "radius dish????". Go to page 2 of that and near the bottom is my method. Very easy and gives a true arc of a circle. Why doesn't someone just calculate and offer a spreadsheet that has the offset for each radius up from a 24" long line" then we wouldn't all have to make the calculations?

Or you could stretch a 52' string down the hall and use it as a huge compass!

The only pictures I didn't put in that little tutorial were the enclosed, showing how different a true arc is from one generated by the bent batten:

[ruby@magpage.com]

Rusty:
A couple of months ago I posted an easy method of drawing an arc of a circle. The method with the bent batten mentioned above will get you close, but will not be a true arc.

Go to "building tools" and look on page 2. A few down is the topic "radius dish????". Go to page 2 of that and near the bottom is my method. Very easy and gives a true arc of a circle. Why doesn't someone just calculate and offer a spreadsheet that has the offset for each radius up from a 24" long line" then we wouldn't all have to make the calculations?

Or you could stretch a 52' string down the hall and use it as a huge compass!

The only pictures I didn't put in that little tutorial were the enclosed, showing how different a true arc is from one generated by the bent batten: