Serious help with tool paths

[Anonymous]

Okay yes another tool path help thread.

I have been trying for 3 months to get a workable guitar from the attached f360 file.

I can't for the life of me figure out which paths to use where and the settings are a complete mystery...all I know is that I cannot get a smooth finish, don't know how to do the back and the front, the cavities don't match the model (only by 1-3mm) I get nasty grooves in the top that are 1/8" lower than its neighbors,

Isn't there some kind of algorithm for beginners that sets up a "safe" CNCs tool path worksheet?

Hell I don't even know when to use a 3d path vs a 2d path...so I end up with pickup routes that are cut the width of the bit, but the middle needs to be hogged out.

Yes Im an idiot...but it would be a lot easier to order the templates and hand route them out...Im so frustrated...and advice or help would be greatly appreciated.

Home built CNCs machine 1000mm x 1000mm

4 NEMA 23 motors

Arduino grbl 

THANK YOU!

Ron

[johnswetz1982]

1.) Is the back of the guitar supposed to be flat when finished?

2.) Are you only going to be making one of these?

If you hover your mouse over an operation it tells you what that is used for or best at. One thing that is no obvious to newer users is that 3D operations are model aware and will not cause gauging, 2D operations YOU have to tell it where it can and cant go and will only follow that and may cause gauging if you do not contain it right. I'll take a look at this and get back to you.

[johnswetz1982 · Accepted solution]

Well you certainly have the modeling aspect down and that is half the battle. I would suggest going thru some for the NYCNC or Lars Christensen videos to get a better idea of what toolpaths do what, there are also the CAM samples and tutorials that come included with Fusion. I think part of the trouble you were having was the setup stock you were using.  I just changed it to a rectangular block. You were going down the right path. I rough it out (adaptive) to remove most of the stock, do contours to clean up from the Adaptive. Then depending on the shape pick a finishing strategy (parallel for this).

I just dont know If the back is flat or has curve to it and what the feature is that is below the bottom pickup but have attached your example that should be 85-90 percent of what you would want. You have to check the feeds, speeds, depth of cut, etc.

I added 2 more holes on the bottom that I would machine thru to give me a reference to machine that back depending on what it is like.

[daniel_lyall]

Have a look at the guitar videos in this play list https://www.youtube.com/watch?v=kVWyh7RQcjA&list=PLQ5pqs2eIFYRGwtYYBkecStqv61aaX8Y1 

They where done by crp and one of the fusion guys that makes guitars for fun, if you do a search through here there are quite a few guitar related posts and on facebook, they have a group for fusion and guitars. NYCCNC want help very much since you will be cutting wood for the other part you could make for the guitars that are not wood it may help somewhat.

[Anonymous]

Thank you!!!!!

You are correct I kept the stock sized piece visible...I am attaching the model with the back exposed.

Is it possible for me to put the neck in this project too? It is hard getting the measurements exact between two files.

Thank you,

Ron

[daniel_lyall]

Have a look at the attached model I have added patches to some parts of your model to make it easier for the finishing toolpath and to show you what patches are good for. 

[Anonymous]

Interesting. so basically I could have a separate model for the pickups and trim cavities, and then I can design the bodies separately then finish the bodies then use the cavity model to route the pockets?

That way I could have several versions of pickup layouts that I could drop in any of the bodies I create?

Thank you! 

[johnswetz1982]

You could do the several different pickup with one body, but much like the back, you will have to have some reference point that you would set on the body to be able to use as your work offset. 

[Anonymous]

Well that is where the neck comes in. The distance between the bridge and nut is the scale length. All the guitars I’m making are 25.5” scale length. The neck mounts the body at around the 16th fret. The spacing of the frets need to be highly accurate to .001”

the line of intonation (the point where the strings make final contact with the bridge) must be the scale length - .5” for intonation.

so it is critical that modeling a guitar that the neck is in the same project. Once the neck and bridge are in place you can move the pickups front to rear but not by much...6” on a 22 fret guitar and 5” on a 24 fret guitar. The pickups themselves are just over 2”. So making a generic pickup layout wouldn’t be very difficult, they need to be centered on the centerline.

my question in this case is can I have the neck and body in the same file, and manufacture them separately. It appears just turning the visibility off does not work.

[seth.madore · Accepted solution]

You can have an many components in one file as you want and manufacture them at any point. When you create your Setup, select the Model you wish to machine (this is done at the Setup level).

The other approach you might want to take is to use the Derive function and put the Neck into another file on its own and apply the toolpaths there.

[daniel_lyall]

You can do near anything in fusions cam, the patches I added to the toolpath instead you can add them to the setup and they will work across all toolpaths.

It would be easier to have one version guitar to each model, you can keep the setup constant by having it as you have it now with the dow pins, you would just import the setup into the model put the guitar model onto it then go into cam.

[Anonymous]

Okay here was the outcome of the sample tool paths provided. 

I realize now the flip pins pins have to be bored at the full stock thickness. Also I would need to do the back first because once the top is carved there is no flat surface to clamp down. I have no idea what caused the knob cavities to turn into crop circle hell.

i guess some of us aren’t cut out to be cnc guys

[daniel_lyall]

The bits that look really bad it could be tool defection, the machine going to fast, the cutter pulled out and or put to much strain on the machine and it lost position.

The lines that look like the tool not lifting up to a clearances plane or no home position set.

Just wait to you forget to set the tool hight on a tool and it goes straight through a bit of material, or even worse you set the machine on fire, do not let a setback knock you back, use it as a lesson.

Just repost the model how it is now one of use will see what is wrong if it is in the tool paths and straighten you out.

[Anonymous]

It’s funny the first run I had no idea I had to calibrate it...so the router plunged straight through the spoilboard, table and burned out the router.

[seth.madore]

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@Anonymous wrote:

i guess some of us aren’t cut out to be cnc guys

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That's a line of self-defeating B.S. if there ever was one. Even the best of us do stupid sh!t every now and again...