Machine to engrave Stainless steel?

[Ian Wilson (AUST)]

Hi Creekers,

I've knocked back quite a few jobs which requires colour filled, engraved stainless steel. My Epilog only etches. Starting to research purchasing a second hand machine.

Any recomendations of a Brand /model to do the job? Small sizes ( usually less than A4 and run size of about 20 off at a time).

I have noticed a second hand Gravo graph IS7000, besides being a little big, would this be ideal? Any other suggestions?

Kind regards,


Ian

[Lucy Lee]

Hi Ian,
usually laser machine with oxgen assist can cut stainless steel

Hi Creekers,

I've knocked back quite a few jobs which requires colour filled, engraved stainless steel. My Epilog only etches. Starting to research purchasing a second hand machine.

Any recomendations of a Brand /model to do the job? Small sizes ( usually less than A4 and run size of about 20 off at a time).

I have noticed a second hand Gravo graph IS7000, besides being a little big, would this be ideal? Any other suggestions?

Kind regards,


Ian

[Rodne Gold]

You can use one of 2 methods 1) CnC type rotary engraver/router (it's not easy to engrave stainless however , even more difficult to cut)
2) Electro or chemical etching. You can use your laser to etch away a resist or mask and chemically etch where the resist is removed.
Search the boards here for chemical or electro etching or for ferric chloride , you should see some more precise instructions.

[Mike Null]

Besides ss being difficult to engrave and especially difficult to achieve depth sufficient for colorfill it chews up tools in a hurry. In other words unless you are being paid lots of money to do this kind of work and it will be a continuous source of business I would walk away from it.

See other recent threads on New Hermes/Gravograph machines before buying.

[vic casware]

Hi Ian,
I do stainless plaques on a regular basis,
My Dalgren 2516i does a nice job with the right carbide cutter
and i usually get twice the price for a rotary engraved plaque over a lasered one.
Most people still like the feel of the depth that rotary gives.
I am now also doing both laser and rotary on the same plaques
Rotary for wording and laser for complex logo's and pictures.
I thing most of the rotary engravers can do steel, some faster than others.

[Gary Sheriff]

Hi Ian,
If you have the right laser, then a laser is great for engraving deep into steel. Please see the photos below. The first is is .030" deep into aluminum and the second is .010" deep into stainless steel. I used a Trotec Speedmarker - 20 watt fiber laser. The photos were taken of the part directly off the laser. No secondary processing.
Aluminum 4.JPGSteel 2.JPG

[Dan Hintz]

Hi Ian,
usually laser machine with oxgen assist can cut stainless steel

Cut? Yes. And at our power levels, speed would be painful and the cut would be pretty bad.

Engrave? Not with any clarity or repeatability...

Hi Ian,
If you have the right laser, then a laser is great for engraving deep into steel. Please see the photos below. The first is is .030" deep into aluminum and the second is .010" deep into stainless steel. I used a Trotec Speedmarker - 20 watt fiber laser. The photos were taken of the part directly off the laser. No secondary processing.

Gary, at what speed were those processed and/or how many passes?

[Mike Null]

Gary

+1 on Dan's question. Wow, that's pretty good stuff.

[matthew knott]

+2 on Dan's question! Also when you say no second processing it looks like the mark has been given a quick blast with a bead or sand blaster to clean it up, we normally get a slight colour change due to the heat affected zone that needs to be cleaned away!

[matthew knott]

Ps chemical etch is definitely the best way to go on this, laser is fine for small areas with very fine detail is required and money is no real object ( tooling machining) but on signs you can do A4 sheet size in minutes with a cheap machine. I saw one at a show, the whole kit for less than$1000 and the results where amazing !!

[matthew knott]

Something like this http://www.megauk.com/pdf/Mega-Metal_Etch.pdf

[Gary Sheriff]

Sorry for the delayed response guys...I don't recall the exact number of passes but it does take minutes using a 20 watt. .030" into aluminum is very deep and took about 12 minutes, but again that is very deep and I wanted to check the extremes of what I can do. I never did venture to go deeper, but I was extremely impressed with .030" The actual sample looks better then the photo. One of the best samples I have done in 15 years. The entire logo is about 1" just to give you an idea of the clarity of the close up photo I took, especially the "R" with the circle around it. I didn't measure the "R with circle" but my guess puts it at .090" diameter. The steel sample is .010" deep and took slightly longer (because it is steel). Using a higher powered laser will have a dramatic time reduction.

The galvo is a different animal then a flatbed and passes are in the hundreds but can certainly be reduced less less depth. I was going crazy and wanted "deep" so I increased passes. I dont recall the exact speeds, but somewhere about 30 inches per second.

Matthew - no secondary processing with bead blast or sand blast, but I did use a cleaning pass with the laser - that sort of has the same effect as a bead blast. The cleaning pass is simply built into the laser program and is extremely quick. The photo was taken directly off the laser.

On another note since this thread also discusses cutting, I wanted to show some cutting that I did using the same 20 watt galvo fiber - Below are two more photos of "cutting" .020" and .016" aluminum. Sorry - I don't mean to advertise, but these were the only two photos I have and wanted to show what you can do using a galvo fiber. The interesting thing is that I used Corel Draw to make the file and print. Again, I am not intending to advertise, but wanted to show what you can do with today's technology. The "Trotec" cutting took about 3 minutes to give you a feel for process time. The marking took a fraction of a second. The word is just over 1" long. Since this is galvo, it is difficult to use any gas assist - and none was used for the deep engraving or the cutting. The GS is taken directly off the laser. After a simple wipe, it is clean.
IMG_1087.JPGIMG_1129.JPG

[matthew knott]

It's very hard to cut stainless with the fiber as the heat tends to warp the the material meaning the passes don't line up but aluminium works fine. Nice samples Gary but it would be a very slow process to cover a 10 inch area, hours I would think in stainless (days maybe) and I bet the speedmarker is not cheap machine although very nice.

[John Salitsky]

Nice stuff Gary!

I have only done diamond drag on stainless using my IS400 and while I had to use all the pressure the spindle could produce it did work but you won't be adding any color fill to it. I was concerned about the strain being put on the machine though, it made some funky sounds. I only have a co2 laser so when it comes to that I have only used thermark on stainless.

[Gary Sheriff]

Matthew,
I agree about the heat and warping - Trotec has a unique algorithm that helps with the process so that you dont hit the same area repeatedly. Yes - a 10" field is hard because you have to change out the lens. You can get a 7" square field, but going larger really becomes a challenge for deep engraving. Price is actually reasonable relative to other galvos in the market. They start about 30k and are less expensive then most other galvo starting prices. Just to give you an idea, I sold my first galvo 15 years ago. An apples to apples comparison is 30k today Vs about $65K back then. Those were YAG lasers and required 230, 3 phase electricity. They also required a lot of maintenance and lamp changes every 500 hours. The fiber lasers today are maintenance free and require std 115 volts - so you can run them in your house. A 20 watt system will draw less current then a hairdryer. Quite a stark difference in price and technology for sure!