les Paul top

[slpd]

curtate cycloid plugin users

This might help try moving the end of your centre line to 0,0,0

[FAJ]

First, after importing all the measurements into Rhino, I build a patch surface with all those points, like this:



Then I intersect through horizontal planes located 3 mm apart. For example, the intersection with the plane located at 8 mm (3 mm higher than the edge, as the top has a thickness of 5 mm there) looks like this:



It obviously has something wrong near the neck. The reason is the lack of precision in the thickness measurements taken with the dial caliper. After making all those intersections and smoothing the curves manually, this is the result:



The yellow line has the same height as the edge, i.e., 5 mm.

Then I patch all those curves, including the edge. The stiffness of the patch is important, and should be adjusted carefully, checking by means of intersections with horizontal and vertical planes. I have two sets of planes that make this easier to check. For example, this is the result of a check operation for both sides of the top, using vertical planes:



Once this is done, I trim the surface along the curve near the edge:



And substitute the missing surface with a plane:



This way, I avoid the complex surface that the patch operation generates in that area. It is not totally flat, and only adds unnecessary complexity to the NC files. A flat surface is the best way to go when routing the binding channels. Once the bindings are glued, I manually carve a small depression around the edge.

The inside of the top has its peculiarities, complicated by the fact that the thickness is not uniform and that there must exist flat areas to glue the neckblock and tailblock. However, this is not applicable to a Les Paul top.

[slpd]

FAJ

Nice info

[sdantonio]

SLPD,

I have also been having a lot of problens with the plugin. To the point where on a new design I will try it once then give up on it. I did a rendering of a benedetto top (similar to an LP, but much larger and designed for a hollow body jazz guitar. I haven't put in the f-holes or yet.

This is the manual sequence I followed:

1. Make outline of the instrument
2. Establish a centerline and a lengthwise arch
3. Divide centerline into 20 points
4. establish perpendiculars from the points to the outside edge and lengthwise arch to determine distances.
5. Use CCycloid (attached) to manually make the curves and import them into CAD system (in my case Rhino).
6. Loft surfaces (surfaces may be disjoint and not connect well at this point).
7. drape surfaces.
8. remove everything but the drape and the outline.
9. trim the drape using your outline.

You are left with one single perfect surface ready for your CAM software.

The proof however, is in the cutting, and I have to finish my router before I can do that.

Took me about a day to do this one, but once the technique is down it should only take a few hours.

[slpd]

sdantonio

I haven't used the drape surface yet.

I will try it when i have finished my file.

Has anyone any ideas as to create curves on the top at the neck joint.

I have tried arch, bezier curves, and other curves but haven't managed to find an answer myself anyone else any ideas

[turmite]

slpd when I did mine, I laid out the lines for the neck with the correct angles. I then used that to lay the side view curve of the top from the neck joint to the bridge end of the body. Remember the neck on an LP is at a rather steep angle compared to many guitars. This angle allows for the top curve to flow very well with the neck. I will used the neck dovetail to simple cut through the body surface and position the neck at the correct height.

I don't know if that made sence or not.

Mike

[slpd]

turmite

I think that makes sense to me.

I have my neck angle at 3.5 from the binding.

I am specifically talking about the curve around the neck and toggle switch area

[turmite]

slpd,

Are you talking about the curves used for the creation of the top surface?

Here are my wires but my body is a double cut and may not be exactly what you want, though I did use patch for the top surface. I created my curves initially by creating a sketch of what I wanted then used the curves manipulation of control points to smooth them out. I did those in the side and front views and would hide everything I didn't need so as to keep the confusion down.

Mike

ps
LP1 is the wires I used
LP2 is the wires and initial surface attempt.
LP3 shows the long curve and the surface using the patch command.....I think???

ppss or is that pssssss??

I forgot to add, that I used a quasi copy of a Les Paul and the Stew/Mac plans for the overall height dimensions of the top.

[turmite]

slpd and others. Please notice in Faj's post above that there is a distinct flat around the primeter of the guitar body. I have seen this on many builders bodies and on several of the prints like FAJ was so kind to share. I have not however, ever seen this on a Les Paul body. Is this something that is on some Les Paul's and not others? I.e., model or year changes???

Mike

[sdantonio]

Moke,

regarding the flat around Faj's top. This is placed there on jazz archtops and on violin family instruments because there is typically a 1mm or so deep recurve around the edge. This is usually done with scrapers after the top (or back) is pretty much at it's final shape, and then often once again whan the plate is joined to the sides.

On an acoustic or jazz electric intrument it frees up the top to vibrate a little more and "opens" the instruments vioce. As you said, it is not typically on most LP's, but having done in on so many violins, I just have gotten to the point where I prefer the look, feeling it's a bit more graceful. This recurve on a jazz archtop is typically about 15mm wide and 1mm deep (as required to free up the voice). On violin family instruments it is typically twice the distance from the edgo to the purfling.

On an solid body it is not necessary, but it can add one of those undefinable things that a guitar player might look at and say "something about this looks nicer, but I can't put my finger on it"

Steven

[turmite]

"On an solid body it is not necessary, but it can add one of those undefinable things that a guitar player might look at and say "something about this looks nicer, but I can't put my finger on it" "

Steve isn't it funny? I have nearly that same impression except reversed?

No kidding, I look at one that has the flat and it just seems to not have that "flow". I bet scraping the purfling on one of those that doesn't have flat would be the pits?

How is your Rhino education coming? I'm still pluggin but slowly.

Mike

[sdantonio]

Mike,

When the recurve is done properly it is no longer a flat, The arch goes fown gracefully to about 15 mm from the edge, then dips down below the edge of the guitar and then comes back up to meet with the binding. No straight parts at all. Just gracefull curves. But them I'm used to looking at them that way.

Scraping the purfling takes a lot of work, especially on the larger instruments. A friend of mine just did 2 cellos revently (top is about 28" X 30X. That was a lot of scraping.

The Rhino education is comming along. Slow, but it is comming along. Your recent post lead me to the discovery of "patch", where I had been using loft all along. Earlier I was extatic about the discovery of "drape".

Steven