Sweep 2 Problem in Neck/Headstock Transition

Hello All -

I’m brand new to Rhino and am Tele Headstock Issues.3dm (425.5 KB)having trouble getting the curves to become solids in my guitar neck. I need a flat spot for my locking nut, but those curves seem to “wrinkle” or somehow ruin the smooth transition from the back of the neck to the headstock. I managed to get an okay transition at the heel with Sweep 2, but I’ve hit a wall with the headstock. Any help would be greatly appreciated.


Hi Bill - what should happen here (for example), between the vertical blue line and the arced curve on the right?:

Do you have images of the details ?


Hi Pascal -

That flat spot is a transition from a semicircle. Most guitars just leave in a small gap or overlap (between the locking nut and the edge) and keep the curve. The blue line is where I’m trying to blend the shapes without a gap.

Here is the best I’ve gotten so far. The Sweep 2s are both still show kinking and a kind of tearing.

Tele Headstock Issues.3dm (557.0 KB)

Is this close to what you’re looking for? I had to rebuild and rework all of your curves to just get something close to proper surface continuity. This is very difficult advanced work.

Stratosphere -

Outstanding. Yes, that is exactly what I’m trying to do. Yours looks beautiful and perfect to me (without, of course, having viewed it with the Analysis tools). I would appreciate it greatly if you could share your .3dm files, steps and/or processes with me - starting with how you “rebuilt and reworked all of my curves…” Did you Sweep 2 after doing this or use maybe Network Surface from Curves? I think I would learn a lot from this, as I’ve spent more time in this area than all the others combined. Regarding the level of difficulty… I have met with an unusual amount of frustration in this section, but chalked it up to inexperience and a very broad and deep piece of software. Any details you would provide would be greatly appreciated.


I stopped uploading files long ago. Most of the time you don’t get any acknowledgement let alone a thank you. You’ve just done someones work for them and they learned nothing from it. With Rhino it’s nearly impossible to learn anything from just a file. For instance your neck is Degree 2 which makes it impossible to properly match higher degree surfaces to.

Watch these tutorials VSR Shape Modeling For Rhino Tutorial Of Audi Q5 Part01 - YouTube You’ll learn a lot. You don’t need VSR to do this it just makes it faster. You just need to understand how to properly rebuild surfaces and match them. Surface from edge curves is my go to surface command.

Here are some tips to clean up the bottom of your neck.

Stratosfear -

In case I wasn’t direct or specific enough before, I’m truly grateful for your knowledge and expertise and yes, THANK YOU very much for your assistance. I can imagine that others have taken advantage in the past, but I find myself on the bleeding edge of a learning curve, and for months I’ve been switching back and forth between working things out (by T & E) in my project, and looking through assorted and often random tutorials which may address my technical questions. That has resulted in a lot of wasted time. That you would lend a helping hand is a wonderful thing and I aspire to one day become as knowledgeable as you are, and return the favor to others in need. By the way, this is just my first neck project, and I need to learn this stuff so I can do necks (and bodies) in many styles and dimensions, as a prerequisite to making my new invention available to the fretted instrument market. As such, I would certainly be willing to pay you to help me not waste so damn much time looking for solutions that are easy for others, but difficult for me. If that is of interest to you let me know, otherwise please know that I’m grateful for your help regardless. Either way, have a great Thanksgiving - I’ll spend most of mine rebuilding curves and surfaces!



Like Bill you certainly have my thanks for your educational efforts and I do think there are many here in the forum who are, “paying it forward” as their skills improve. That said if feeling like some further charity work over the Holiday, I’m actually baffled by your first red model. Any light you could shed on how you generated the indicated surface would certainly go a long way towards helping me better understand complex surfacing and I suspect would be greatly appreciated by the 100+ people who have checked in on this topic.

Thanks and Happy Thanksgiving,


I used another program that has an amazing degree 5 patch command to quickly create those surfaces. I wasn’t sure what the design intent was. It’s not my preferred approach but it’s probably good enough considering the need to sand the finished form. I’ve tackled this design challenge before on this forum. The image below shows what I consider to be best solution. You just need to accept that you probably won’t hit your design intent curves exactly.