Looking for advice on a laser engraver?

[mark walker]

Hi Mark, from the list of things given that you want to do at the moment I would say that you don’t need the 60w which would only give you an advantage of more speed when engraving and you could cut thicker materials faster. I would say that bed size is an issue however and to look at what you might be doing in the future. If the supplier gives you a good upgrade path then you could trade up when needed- if needed. Most things engrave at a very low power setting on my laser which is a 70 watt machine, I sometimes wonder if I spent too much and could have spent the money elsewhere more wisely. Hope that helps, it’s up to you.

Mark. 😀

[Rodney Gold]

Speed is what counts with a laser – time is money. Most materials will engrave at 100% speed and less then 100% power with a 25 w , let alone a 40w.
Watts are not watts either – the power density of a 30 w laser can actually be more than a 200w one , IE the spot size of the beam concentrates the power , 30 watts spread over a 0.003″ spot is actually more potent than 200w spread over a 0.1mm spot. Thickness you can cut is not power dependant to a large extent but is dependant on the focal length of the lens you use and its depth of field.
Sterling silver will not engrave on your laser , it will with a special coating , but cleaning it with silvo will remove it. Slate too will be problematic as its not a consistent material and in some areas you might get a white mark , in others you might get black depending on whats running thru the slate.
Leather requires mickey mouse power , as does marble and granite , denim requires even less as does anodised ally , you can’t engrave light anodised colours as the mark a co2 laser leaves IS white on ally. (unless you use a coating)
There are a huge many more factors to look at regarding lasers , I can post these chapter and verse for you , BUT the most important is service , warantee and backup. Particulairly important is the warrantee on the source , you need at least a 1-3yr NO QUIBBLE NEXT DAY REPLACEMENT type warantee IN WRITING. Be VERY careful in this regard , the other bits and pieces in a laser hardly fail , the sources are notoriously flaky.
I would rather buy 2x 30w lasers than go for 1x 70w unless the majority of your work is cuting, same applies to a source upgrade , it makes better sense to get another machine than upgrade the source.
Bed size is also a double edged sword as the laser tends to go out of alignment and starts cutting badly at the farthest reaches of the bed. However a large bed size can let you use twin heads and thus double production (tho you 1/2 the power and cutting area)
I have used a lot of lasers , I might be biased , but I think something like a 30-40W GCC (laserpro) explorer II is just the ticket. ( we have 3 of them)
They are fast , have great drivers , are reliable and use a Coherent DEOS sopurce which IMHO is far better than the synrad source. Made in china (well made) and they come with all the bells and whistles (most of which , like rotary engraving , stamp and 3d mode , are worthless)
Have a look at some of my posts on various laser boards
http://www.nbm.com/index.php?page=aemsg … iscussions
http://www.sawmillcreek.org/forumdisplay.php?f=8
http://www.engravingetc.org/forum/index.php
for more info on what I think is really important , I have also posted a lot of hints and tips.
DO NOT underestimate the speed aspect , do not believe the specs or the salesppl , you have to let all the machines you are considering engrave the same file on the same material – YOUR file , not a canned demo and time them and look at the engraving quilty with a 10x loupe!!
If you have any other questions , don’t hesitate to ask.

[Mark Shipley]

Hi Mark, Many thanks I’ll be in touch later today – thanks.

Hello Rodney,

Thanks for such an informative reply. You say that Silvo will remove the ‘engraving’ of Sterling Silver, is this the same for any highly polished metal that is engraved by use of a topical coating?

Slate is something I would really like to do as I think I’ve found a great little niche in the market that needs filling 😉

I’ll keep this short as I’ve got one of those here, there and everywhere days just about to start – but, it’s strange how you’ve mentioned the GCC Explorer II because the machine I’m looking at is the 30-40W GCC Spirit. It’s smaller overall and has a smaller bed than the Explorer but it would fit perfectly into our working environment. Plus, and I know this might sound silly – it uses USB connectivity and as the machine I will buy will be running from a laptop – have you tried to buy a laptop with a printer/parallel port these days? It’s like trying a buy a television in any colour other than silver!

I will certainly look at the links you have provided – thank you, much appreciated!

Mark

[Rodney Gold]

The way the laser “engraves” metals (co2’s that is) is that you apply a film of molybdenum trisulphate to it. The heat generated by the laser fuses a “glaze” to the metal surface. Its much like pottery glazes and is merely a surface coating bonded at a VERY shallow molecular level with the substrate. Silver tarnishes badly and thus needs abraisive cleaners (as do brass etc) and these remove the marking. On brass using a cleaner like chromic acid is even worse as it almost instantly strips the “engraving”. another problem is the adherence of the coating to highly polished metals , it has to dry and often it flakes off whilst engraving.
Slate is fine , tho the problem is contrast , light stone will engrave with almost no contrast at all , the best stone to engrave is jet black granite or marble that engraves white.
As I said the composition of slate will determine the colour of the mark and on one piece , you can often get a sudden change.
One can use a laser to vaporise a mask like polyester vinyl on stone and then sand blast it for far greater depths , one could even spray paint the engraved sections and remover the mask after. The big problem with colour filling stone is the porosity of it.
The spirit is a new machine , we made a small mistake in getting the first itteration of the Explorers , bugs and all (were promptly fixed , but we ended up being beta testers) I have learnt that it’s sometimes pudent to wait a while before rushing in to purchase the latest and greatest.
The explorer has got usb as well and is not that much bigger then the spirit , if you can fit a spirit , you can fit an explorer.
We run 3 explorers of one puter , 2 with printer ports and one with USB. There is very little difference in speed doing so , as the file loads into the machine and is run from there , there is no handshaking during lasering with the host puter.
Essentially the 1m x 500mm bed size of the explorer is a huge bonus , pass thru means you can do stuff like 3-4m long and 1m wide.
The spirt has a sq meter area of 0.3m2 vs 0.5m2 of the explorer. The max engraving area is actually 985 x 508 and not 812 x 508 as the literature suggests.
The local agents here say the spirit is a great machine , but they also said that of the explorer when it was brand new.
the only real bugbear with the GCC lasers is their crappy manual (the printed ones I got with my mercurys must have been written by a tongan speaking tibetan monk that had had a full frontal lobotomy:)
Albeit the rotary attachment works well , it is not the best out there. Their drivers are fantastic and the machines engaving and cutting quality is too.

[Rodney Gold]

duplicate post – arrrgh