Wasn’t really sure where to put this, its got some CNC in, but I think its a more general thing.

Im working towards a watch, I think I have case work mostly sorted, next onto the dial.
I have made a few dials, but they are quite plain, I want to make something a bit special.
Guilloché Enamelled dial seems like the thing 🙂

So how to cut a Guilloché dial?
I tried using a V bit cutter in the spindle. The results were less than inspiring.
Rather than a single bright cut it looked like someone had dragged a stirring spoon through the metal.

I don’t have a straight line engine, which is the more traditional way to do this.
I do have all the bits to build one, but that’s another story…..

I saw a video somewhere of a Kern mill using the servo spindle to drag a single point tool around and do some fancy engraving.
I think it was Josh Hacko over in Australia.
I don’t have a Kern (mega bucks!) either, but I do have my own CNC, and as I built it I have no problems with modifying it 🙂

Straight line engines hold the tool in one position and the work is mounted so it can change its angle if required.
For a lot of pattern cuts this isn’t needed, so a fixed tool/work relationship is easy to do – Vice on a 3 axis machine.
So first order of work – how to hold an engraving tool?
My spindle doesn’t have a lock, so I knocked up a tool holder and attached it to the Z axis.

Then I tried cutting some straight lines in a test piece of aluminium (short video here):

[url]https://youtube.com/shorts/wUKpJHmHWrU?si=RnG1CA7dngLOeP3N[/url]

Looks plausible 🙂

There followed a short diversion as I looked at patterns, poked the internet for information and wrote some software….
Roger Smith has a good few videos on dial making, including a nice explanation of the sequence of cuts for a basket weave:
[url]https://youtu.be/LBiiDpexmA8?si=7MZtgzkG6iEUDlvz[/url]

How hard could it be?
As it turns out its not very hard, but you do have to pay attention to the details…

Test cut in aluminium, followed by a test on copper:

Looks like Lego chequer plate

Basics sorted, definitely possible with my tools 🙂

Now to design a dial…

Fired up Fusion360, did some CAD and other computer related shenanigans and ended up with a set of code for the CNC.
Back to the garage and do some test cutting:

Had to make a couple of tweaks, but then its time to cut a dial blank.
First get some help to secure it:

Then set the machine running:

halfway through the basket weave centre:

Basket weave done: