Metal Gobo

Has anyone tried to make a metal gobo using X-carve? I spend approx 1-200 per month on custom one time use custom gobos and I thought if this can cut them then it makes financial sense to purchase the machine for that and all the other things it can do as an added bonus.

As far as I know the challenge would be getting intricate detail on a small (around 80mm width and 1-2mm thickness) piece of metal such as cursive font.

(for those of us unfamiliar with the term: https://en.wikipedia.org/wiki/Gobo_(lighting) )

I’d imagine you’d want to look over the aluminum machining threads on the forum. Your limiting factor is going to be the size of the bit you’re cutting with. I’m not sure what the smallest bit is that people have had success with on aluminum (or whatever metal you think would be appropriate).

I’ve successfully cut 0.3mm copper sheet with the X-Carve.

Not sure what gobos are made of, ally?

But top tip, with thin sheet metals, sandwich between two sheets of cheap thin plywood and clamp whole lot together. This stops some intricate parts being pulled upwards by the cutting bit.

Cheers

Ian

Your best bet with something like this will be with a vacuum table to hold the thin stock very flat and also making sure your tool paths are meant for such thin stock. CAM software like HSMxpress has tool paths designed for thin stocks and adjusts the way the paths are setup and worked to reduce the stress on the thin stock so it does not get pushed or curl while being milled. You might want to check into something like aluminum roof flashing. It is easy to come by, the thickness you need and easy to work with yet holds the carved shapes very well. As far as how small of a bit you can use, that will also fall right back onto the tool paths. With a small end mill in the 1/32" or smaller you will need to slow WAY down and make sure you have a very well calibrated bed so it is even. I would suggest going with a vacuum table, and doing a warping feature like when milling a PCB. Once your stock is on the vacuum table you would use a conductive probe (a old broken end mill or a fine engraving end mill work great) and use something like Chili Peppr or a controller like the Planet CNC system and map the stock with the probe. This will account for the ups and downs of your bed if it is not perfectly level and will adjust the endmill as it mills to avoid high spot pressures on the small end mills which will break them very fast if not avoided or allowed for. I would suggest you have a good supply of end mills handy and expect to break a good few when you are getting the system dialed in. But with the above considered there is no reason at all that you can not produce one off gobos or crank out a hundred copies of one design in a day or two of milling.

Please keep us posted how this goes. Very interested in how it turns out and now fighting the urge to give it a whirl myself for fun and practice on such thin stock.

If needed a could give a test or two a go and post some pics if that might help you out.

I’ve wondered the same as well, so would love to hear if you do end up making a couple.

Have you had any luck creating gobos? Any tips you could share?