Acoustic Guitar Neck - help please

[Gasawdust]

I have a copyrighted STL file purchased from Genone Luthier. It’s a 12 fret slotted neck and I have successfully carved the backside several times and particularly like the heel/neck/peg-head transitions.

I want to also use the file to carve a paddle type headstock and therein lies my problem. I can’t edit out the slots in the STL so trying to ignore them.

I have split the full neck component into three levels, heel, neck, and headstock. I have tried to use the “Clear area of selected component inside the selected vectors” but when I go to the simulation it still carves the slots in the headstock but in a weird way. See screenshots.

Without being able to post the file can anyone lead me to the answer. I don’t know how to modify the STL in any other CAD package or I would do that.

Any help appreciated.
Tom

[adze_cnc]

I have tried to use the “Clear area of selected component inside the selected vectors” but when I go to the simulation it still carves the slots in the headstock but in a weird way. See screenshots.

What are the "selected vectors"? If they are just the ones that define the slots then yes I can see it cutting like this.

If they are for the slots and the outer profile of the head then yes there is a some oddness. What is your "Boundary offset" set at?

[martin54]

When you say you can't edit the STL is it simply a case of not knowing how to using Aspire

[Gasawdust]

Adze…..The boundary offset is set to .3 inch. Yes, it’s just the slots I’m trying to avoid carving by using their vectors.

Martin….Yes. Not aware that Aspire can remove these slots (elongated holes) from an STL.

[adze_cnc]

If the boundary is set to 0.3 inches and your cutter is smaller than that the cutter is going to go past the edges of the selected vectors. Also if you are only selecting the slot vectors you are telling Aspire to cut inside those slots. You would need to tell Aspire to cut between the slots and the head boundary by selecting both sets of vectors.

I seem to recall a post here not long ago that showed how plug holes in an STL file in Aspire. Might be worth prodding the forum "Search..." field above to see if it can be found.

[Gasawdust]

Using a 1/2” cutter. Have done several searches but will try more.
Reached out to Genone for help but no joy there.

[Gasawdust]

They cut pretty decent leaving a small bit of cleanup as a slotted neck.

[adze_cnc]

I neglected to ask: is the result of the simulated toolpath above that of a roughing or finishing toolpath?

Finishing toolpaths with a boundary offset of 0 will move the centre of the bit to the edge of the vector. By having a 0.3 boundary offset the centre of the bit will be moved to 0.3 inches away from the selected vector. 0.3 is greater than the radius of the cutter so it will try to cut into the slot. You’d need the boundary offset to be less than 0.25 inches.

[Gasawdust]

Adze,
It is a roughing toolpath with a flat end mill.
If I can find a way edit the slots out of the STL I think I can make the rest of it work.
Thanks for your input.
Tom

[martin54]

You have the vectors for the slots, I would try making a component from them to fill the slots up rather than trying to actually delete them, I am sure there are a few ways that this could be done but unfortunately I am not to good when it comes to modeling

[dealguy11]

Is the back of the headstock flat and symmetrical from side to side? That is, does it angle side to side in either direction, or does it go straight across?

If flat, then there is a way to create a cross-section vector that could be used to create a component that would "fill in" the holes. This is not a single-step process, so see if you want to try this.

1. Create a cross section vector of the neck starting from the top of the headstock to the bottom of the neck. This can be done with the "Measure" tool, last option. Make sure you pick points exactly centered on the neck for this operation.

2. Cut the cross section vector at the bottom of the headstock using the node editing tool. Discard the portion that runs along the neck.

3. Modify the remainder of the cross-section vector by adding legs if necessary. The one at the top of the headstock may already be there. You'll have to create one at the bottom that is exactly equal to the model thickness at that point. You should have a vector that looks like this at this point:

4. Create 2 straight rail vectors, parallel to each other. One should be perpendicular to the top of the headstock, touching the top of the headstock. The other should be parallel to the first at the bottom of the headstock. The distance between them should be exactly equal to the length of the cut cross-section vector.

5. Use the 2 rails and the cross section vector to create a 2-rail sweep. Set the combine mode to "Merge".

6. Select the 2-rail sweep component and the outline vector that you already have for the neck. Use the "Clear area of selected component outside selected vectors" tool to cut the 2-rail sweep to the shape of the headstock.

Now you should have filled in the holes. If it looks right you can bake the neck component to the new 2-rail sweep to make the change permanent.

[Gasawdust]

Thank you Steve!
Out of town for a couple of days but can’t wait to get back and try this out. I was at my wits end.
Tom

[dealguy11]

Looking more closely at your original posting, I see there is a small curve at the top of the headstock that I missed before. So you will need to make a couple of modifications to the instructions above. I would make the rail vectors first, moving the top rail towards the neck until you're past the curve. Make sure the rail at the bottom of the headstock is far enough away from the curved part of the neck to avoid problems there as well. The important thing is just to bracket the slots on either side.

Now create the cross-section vector. Before trimming the cross section, check to make sure there are legs at both ends. Run a line from the bottom of one leg to the other, establishing the thickness of the neck/headstock along the length. Now trim the cross section to the rail vectors. Create legs on the remaining cross-section segment using the thickness line as a guide. The rest of the process is as above.

Good luck!

[Gasawdust]

Steve,
Gave it my first try last night. Now that you opened my eyes to the concept I think it will turn out as I need. I only need to work on smoothing the transition from the headstock to the neck like the original STL.
Greatly appreciate your assist.
Tom