CNC Acoustic Guitar - Neck with Heel

I've seen others using their CNC mill to route their entire guitar neck, heel included. My challenge is, my hand router based mill with a 1/4" shank diameter seems to be limited to short length router bits. It looks like I would need a 5" overall length bit in order to achieve this. (max height of heel is typicall just shy of 4")

Do I have to convert to a spindle based router setup in order to get a 1/2" shank diameter to achieve my goals?

I've currently created the folllowing MOP to accomplish the heel cutting.

My Bosch 1617 router takes 1/2" shank bits - which router are you using?

David

Hadn't even considered an alternate router. I currently use the Dewalt 611 router. Any good sources for a 5" ball nose bit if I swap out the router?

Hi TJP - The longest 1/4" shank bits are bowl cutters. These are rounded edges but a flat bottom. Or you can get an extension. You need to CAD model the bit and the collet to check it will get down to the depth required. The heel is tapered so as long as the taper allows the collet to miss you don't need such a deep bit. Or you can do the piece in 3 set ups, one for the neck then turn it 90degs and do the heel side then turn 180degs to do the other side. Cheers Peter

Have you tried to cut with extra long drill bit ? Ground the bottom end first. Extra long drill bit usually a lot of stock.

Something like this?
https://www.mscdirect.com/product/details/45500923

Or this?
https://www.mscdirect.com/product/details/75641753

Interesting cutters I've not seen before. A bit pricey though.

Something I've used before is something like this;

https://www.amazon.com/Kempston-2080...4189699&sr=8-6

Used with a collet extension like this;

https://www.amazon.com/Techniks-Coll...%2C164&sr=8-44

Generally, you'll need a collet extension with a shank larger than the cutter shank. And sometimes the collet nut diameter gets in the way. Just a thought.

On the heel, you have a nearly vertical face of around 3" tall. Any extension will likely result in a collision, so you need a long tool.

Gerry,
If you could fit a 5/8"diameter insert into one of the 1/2" shank tools you referenced, you'd have it made. I presume these are made primarily for metal working?

I have a 5/8" ball nose up shear bit with 5" overall length, but generates chatter if I try to take too big a bits. Doesn't get much use.

Don't expect a long life for the bearings with that amount of projecting cutter.The increased leverage on the gantry won't be beneficial either.Is appearance a primary concern?If not I would advocate machining the lower section only and then adding the blocks in the first thumbnail one at a time with each being machined before adding the subsequent block.It would mean leaving the job in place for a few glue cure times and a few machine cycles.
Even doing the job from solid with separate setups for the fretboard and each side of the neck will need a longer tool than really ought to be in an adapted hand held router.

Alternatively saw out a blank with a useful machining allowance and find somebody with a 5 axis router to machine it.

I have been cutting mine with a 14 mm x 150 mm bit. :eek: It is scary as hell. :)

That being said, I recently re-did my tooling and paid careful attention to clearance and found that (except for the back of the heel), I can do it all with a 2" bit. As mentioned earlier, design a good slope to the heel to help with that clearance. Your heel looks really huge in those pictures, I think you could get it a lot smaller

However, I've come to conclusion that we're solving the wrong problem here. I'm in the process of redesigning my necks to have an internal heel, made out of aluminum, and that will make the neck more like an electric guitar neck. Will make a post once I get some traction on this again (I have been busy doing boring stuff like building Christmas tree storage boxes and replacing cabinet drawers.

Make a jig to hold the neck on the sides.

They sent me one piece of wood, i cut it sideways. Like warren said

Awesome. Double the necks for a few extra inches.

Quote:

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Originally Posted by warrenb

Awesome. Double the necks for a few extra inches.

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And the billet was perfectly square and parallel, to use the bilett to locate after we split the two apart.
All done on a DMS router with Coloumbo spindle no length problems.