Blogging Fatso!

[Kevin Sjostrand]

David,
Your rims that will be your top should be level, flat, as when you set them on a flat table top, they will lay flat, touching the surface all the way around. The neck angle is set where the heel cheeks meet the body side. Where did you get the idea to slope the rims for the neck angle?
You've probably already looked..Ken's website explains it very well.

Kevin

[David L]

Hey Kevin,
From what I understand (which isn't saying a lot), once the top of the rim is flat all the way around, a slight angle is needed on the upper bout to accomodate the angle of the neck. Ken and John both do it, they just go about it in a different manner. Maybe I'm confusing you by not using the right terminology or I'm mis-pronouncing something or maybe I'm confused (likely).

David L

[Kevin Sjostrand]

Well David,
There you go. So Ken is showing you to do it that way in his instructions. ( I don't remember seeing him doing it that way there. Is this a relatively new process Ken, sloping the top?)
It must work then, he is the pro so you are might be okay with what you have there.
I am an amature for sure. I have gotten my approximate 91.5 degree slope from the 30' radius I put into the top, making sure the area where the fretboard will sit is laterally flat by leaving the center area of the bracing underneath flat. This has worked for me.

You better continue to follow Ken's instruction.

Kevin

[David L]

Hey Kevin,
I'm not even an amateur yet, I'm trying to work my way up to that status. Before I started on this project, I studied (reviewed would be a better word) all the procedures, and this is one that I thought I might struggle with a little bit (there are others). I sometimes wish I could just pull an "I Dream of Genie" or "Bewitched" trick (yes, I'm that old) and blink my eyes or wiggle my nose and "shazam" but then, what fun would that be? Might as well just go and buy a friggin' guitar.

David L

[tippie53]

Ken is correct but to add one point . they are working the upper part of the rim from the sound hole to the neck block. Most builders use the 28 disk as a way to get this 1 1/2 degree angle and to add a bit of radius for top movement . There is a slight radius of the top by the bracing but this is minimal.
Martin uses a 42 foot radius on the top X braces only . all other braces are flat . There are many ways to do this and those of us that use the disks find they help not just for truing angles and kerfing but for gluing. This isn't to say one way is better or worse than another just that there are more than one way to do this .
Martin has everything jigged to remove variability of the process . If you ever get to take the tour do so , you will enjoy it.

[Kevin Sjostrand]

Thanks Ken. I must mention that I do incorporate the opposing neck angle to the top of my neck block, which sets the angle of the top adequately along with using my radius sanding system. However, I like the idea of putting a slope to the rims.
Might try that.
Thanks too John for you guys and your experience and expertise.
It sure helps us little guys.

Kevin

[Kevin Sjostrand]

Tony,
So far on 4 guitars, I haven't encountered the "hump".
My fretboards have all laid on the top nicely, giving me the angle I need at the bridge. However, I like the idea of the slope built into the rims, so I might give it a go on the OM that I'm building next.

Kevin

[David L]

Thanks for all the 2 cents guys, I must have got about 50 cents off of that one, moved me into a higher tax bracket. My rim seems to be okay, Ken turned me on to an accurate and simple way to measure the gap at the neck block, lay the rim on a flat surface (top side down) and then measure the gap, how much easier could it be? Trying to measure it with a level like I was trying to do was just not accurate enough as well as deceiving. Now out to the shop I go to radius the back side of the rim. Thanks!

David L

[David L]

Here's the rim set up in the contour fixture just after radiusing the back side of the rim. No, I didn't take the rim out of the fixture, blow all the sawdust away and clean everything up real nice for the camera, no I absolutely did not. My work area always looks like that immediately after doing some work.

David L

[David L]

Here is the completed rim. Well, not exactly, I still have the notch the lining for the braces. Top still isn't braced yet, waiting on humidity to go down, so it's back in the mold while I'm on hold.