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I'm looking at stepping into a CNC, mainly to make fingerboards and carve the necks.

Any insights?

I do my necks on CNC--mostly banjo necks, but same idea. Cutting necks isn't that big a deal, but it takes a lot of practice to model a neck, heel and peghead transition in CAD, and then convert that into toolpaths that actually work well. Banjo necks, being asymmetrical, present interesting problems of their own. Fingerboards are much simpler.

Dave

Fortunately I have someone to do the programming for me...

I carve the necks on a cnc. Holding and indexing the blank has been the biggest challenge. You also need a long reach bit.

It took a lot of work to figure out what to do first on the blank and how to prepare it for the cnc. But, now I can load up a blank and walk away to do something else. I don't end up with a perfectly done neck waiting only for a fingerboard glue up. I just could not adequately model the heel/shaft/headstock transitions, so i do that by hand. Also, I still have to sand out tool marks.

This is what it looks like off the machine.




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There's a lot of help in this forum. Expect to meme a few mistakes like me


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Ken

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Ken

Still, much time saved and consistency acquired...

Ken, some set neck mishaps?

Programming mistake. There was a move missed. It was a safe Z rapid. But instead it moved in the lower Z location and plowed right through my heel. I fixed it. This is what I mean expect to make a few mistakes. Some test on foam or other material.


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Ken

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Ken

Definitely. I won't be doing the programming myself though, just buying the ready to go programs to my specs...

Uhem good luck with that. Every machine is different and even a perfect toolpath in simulator can go wrong in many ways on your specific machine. I'm not trying to scare you or steer you away from anything. But as I learned a long time ago I had to go in depth and learn from the beginning. Learn to draw in CAD. Learn to create toolpaths in cam. And then learn to operate your machine.
Having said that I think your approach is reasonable. Especially if it's a simple neck that somebody has modeled.


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Ken

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Ken

I agree with Ken, don't hesitate to start this way, but it would greatly help you in the long run to understand how the drawings and toolpaths are created. There are so many ways to approach machining a neck and you may find with time that you need something more specific to what you do than what you can get from someone else, unless the programmer is in house with you which can have that benefit of slightly altering dimensions or final finish. Every machine and program can be a little different and what works great for one may not for another. If the programmer will be in house with you, take the time to try and understand what they're doing. If you can build an acoustic guitar, you can definitely understand CAD and CAM with just a little research, education and practice.
Good luck!

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William Seeders Mosheim
http://www.seedersinstruments.com

Thanks guys,

The programmer will be more or less 'in house'. There are some advantages for me. For one, he has the same machine I want (though smaller) with the same software and such. For two, he has a great wealth of experience in creating guitar specific programs, as he was the programmer at Larrivee before Jean took his toys and went home. For three, he wants to turn his CNC biz into a full time gig, so he is actively and enthusiastically seeking work in this area and will therefore be very available to me. Plus we're buddies in a loose sort of way.

Of course, once things are basically set up, I will endeavour to learn how to do it myself as relying on others while running a biz is dangerous...

I agree with the others. Knowing how to do it yourself is extremely crucial. This may sound horrible, but not having to rely on other people can greatly benefit you in the long run. You just never know when someone may not want to show up or stop putting in 110%. And then at that point, you're up the creek!

I find there are a couple major parts to using a CNC for a neck. (I probably will forget to list some)

1. Wood grain orientation (per species of wood)
2. Programming
3. Fixturing
4. Machining

I have made many Sapele necks on the CNC that came out great. I moved to a different species and boom, the wood blows out. I then would have to change an already "perfect" toolpath to account for a different wood species.

Something to think about. Knowing how to program could save you that headache.

Yup, I'll learn along the road for sure. But I think a neck carving program is a little bit much for an entry level task. I'll leave that to the expert for now. I'll start with bridge alignment jigs or something...

no such thing as a perfect program. In nine years of making military prototypes the closest I came was a two piece housing for a night vision / thermal goggle was one mistake, wrong size threaded hole. luckily it was smaller than it should have been so fixing it was no problem. try making your fixtures on the machine so you can make duplicates, part gets secured to fixture then secure the fixture to the machine. You could try screws were the truss rod will be and cut the slot after. prints show size and shape at a few frets. make some construction planes at the frets distance and draw the shape of the neck and run a sweep thru them then add heel and head stock. Make two programs, climb mill on the first then copy and paste the set up and change the cut to conventional and let the grain of the wood decide which program to use.

Thanks!