Question about Galvo lasers

[David Fairfield]

I've just been thinking about getting a second laser. I was wondering if maybe I should look into a galvo and what the advantages are over a standard laser engraver. In particular, is a galvo potentially better at 3d engraving?

Thanks! :)
Dave

[john banks]

If I can add to this, I also wondered whether they rely on a long focal length lens to keep in focus over their engraving area (due to distance varying)?

[Rich Harman]

The following info only comes from what I have read about galvos so corrections are welcomed.

Not good for 3d - unless you want a starburst effect. The further from the center of the workpiece you go, the more of an angle the beam hits the surface.

The reason for the long focal length is simple geometry. Since the beam has to be steered by rotating (pivoting) mirrors, the longer the focal length = the larger the work area.

Advantages are that they are very fast. Excellent for engraving or cutting thin materials. Not good for cutting anything with thickness due to the beam angle increasing away from center.

[Mike Null]

The real disadvantage is the small size of the engraving field.

[Josiah Gallo]

In my experience, and it depends on what materials you usually process, but we do a lot of metal

Pros:
Super fast marking, you'll experience 20 to 100% faster marking (especially when considering no cermark)
You can engrave depth on metal
More materials (any metal)

cons:
software usually stinks (new trotec promarker is the exception with drivers that work from Draw)
small working area
you could run out of work since all your metal will get marked so fast

[David Fairfield]

Cool about the marking into metal. Can you cut thin metal with it? Like say, a disposable foil pie plate? Thanks for replies so far!
Dave

[Dan Hintz]

Cool about the marking into metal. Can you cut thin metal with it? Like say, a disposable foil pie plate? Thanks for replies so far!
Dave

Josiah's post may have been a bit misleading, David. The ability to cut metal is a function of power and wavelength. A CO2 galvo isn't likely to cut as the power range is typically in the lower range (i.e., sub-100W). A fiber galvo, on the other hand, is quite capable of such a thing.

[Josiah Gallo]

Dan is right, I was assuming we were talking about fiber/yag lasers. That is what we have. I've never considered a galvo co2 laser.

[Jiten Patel]

There is no chance you are cutting metal with a CO2. To be honest, you are not going to cut much with a co2. We use ours for cutting paper/card and it works extremely well. I have tried cutting acrylic. Although you can do it, it is slow, and due to the spot size being quite big, the cut quality is sub-par.

We are looking at upgrading the 30w to 100w+ really just to speed things up, and also getting a carriage system to get in on all the action and fun you guys all experience. Hopefully should be with up in December - cannot wait. Got some great ideas for it.

Software for our galvo is not very good. Very basic and doesn't really allow any flexibility. I have used trotecs software for the speedy's and it's amazing compared.

Main advantages are speed. Processing small items (depending on the lens you have) will be your greatest asset with a galvo. There are 3axis galvos which allow marking fields of up to 850mm x 850mm with a small(ish) spot size, but you are talking a nice chunk of change for one of those. On the wish list.

Dan - 3D printer hey - prototyping or production?

[Dan Hintz]

There is no chance you are cutting metal with a CO2.
Don't be so quick on that button, Jiten... you can do it, but it's not an ideal situation. Coating some tinfoil with an absorber can get you a cut, and if you have something thicker, adding a shot of oxygen to the mix will create a thermal lance and will work just as well. It's not a kW-sized system meant for 1/4" SS, but it's workable in a pinch.

Dan - 3D printer hey - prototyping or production?
Prototyping, for sure... 3D printers simply aren't fast enough for production work (at least if you plan on making money). Granted, it could be protos for someone else, and then there's money to be made, but it's still protos. Quite a few try to use it for production (parts and bits of a larger item, ala reprap), but it's only good for very low quantity or low speed manufacturing where the time between prints is measured in hours, not seconds.

[Jiten Patel]

Dan, you know what I meant, yes you can probably hit 200mph in a go-kart, but it's probably not a wise choice - maybe an F1 car would be a better choice for that situation.

I was considering a 3D printer, for some unique wedding related products which are usually one-offs or very bespoke, and hence can command the appropriate price tag - but simply haven't had time to develop this or look in to it with any degree to detail. Look forward to seeing what you come up with.

[Dan Hintz]

I was considering a 3D printer, for some unique wedding related products which are usually one-offs or very bespoke, and hence can command the appropriate price tag - but simply haven't had time to develop this or look in to it with any degree to detail. Look forward to seeing what you come up with.
If you're the customer, too, then expect to take care of the entire design chain... creating the model (or scanning a physical object) can be a significant time sink in and of itself. Printing even small items is a multi-hour affair. If you're doing one-offs for weddings that require a lot of design work ahead of time, expect the price to be pretty hefty.