[TurkishDelight]

A laser salesperson who yesterday came to our company inspected our machine and told us that our laser tube was defect. He said something along the lines: "The built-in lens is burnt". So I'm planning to send my 2 RECI V6 tubes (150W) back to RECI in China for repair and gas refill. He said that if I use a RECI W8 tube I would have to use a Beam Expander too. Is that true? I'm only cutting acrylic from 2 to 20mm (Actually, I can't cut acrylic thicker than 10mm smoothly atm). I thought that a Beam Expander helps to get better engraving results on tough materials like metal and I wouldn't be able to cut thick material with a Beam Expander installed. Please share your knowledge and expreriences on this subject.

[Rodney Gold]

If it is combined with a collimator that straightens the beam as well (stops divergence) You get an expanded spot size at the lens and can focus to a finer sport than at the smaller beam size .. you will cut much better with the extra energy density you get. Its not essential for your acrylic cutting - would work well if you were , lets say , marking stainless steel without any coating like and just using the lasers power to get a black mark , the higher energy desnity will enable you to go much faster..

[Exsecratio]

Of course as usual Rodney is quite right, another consideration is depending on where the expander is placed it can make alignment a lot harder (you have less space to play with)

best wishes

Dave

[G.Weike-Abby]

Hi，

I think Beam Expander is not important for cutting and engraving.

It is the focus length of the focus lens is important.

And all of the CO2 Laser Tube cannot engrave on metal material directly.

In our workshop,we usually engrave on oxidized metal as our machine card. Enclosed pls find the pic for reference.

And RECI Tube: W8 is a good high power tube. It could cut thicker acrylic.

Abby
G.Weike Laser Factory
[email protected]
[email protected]
laser engraving machine?laser cutting machine?cutting plotter at G.WeiKe

[Rodney Gold]

It's not just the focal length that is important , spot size thru the SAME focal length gets smaller if the beam diameter entering it is bigger... so you can get BETTER cutting and engraving with a beam expander/collimator. apart from that , stopping beam divergence will give you more consistent cutting all over the table. These are not cheap devices and good ones can cost $700+.
I have used my 80w Reci to DIRECTLY engrave stainless steel with NO coatings or brush on compounds and I am not using an expander to do it. Here is the evidence....

[TurkishDelight]

Thanks for your answers people. Seems like I might not need a Beam Expander at all. Yesterday I asked RECI about laser tubes repairs and gas refill. Asked for the price list too. They told me that they don't produce the W8 model atm, "because which is spent long time testing and producing, which maybe affect u normal work!". So the rumours about the stabilization problems of the W8 model might be true after all.

[G.Weike-Abby]

hi，

i have checked with RECI just now. They could produce the W8 Tube(170-195W).

But the delievery time is a little longer than regular tubes.

For your reference.

Abby

Thanks for your answers people. Seems like I might not need a Beam Expander at all. Yesterday I asked RECI about laser tubes repairs and gas refill. Asked for the price list too. They told me that they don't produce the W8 model atm, "because which is spent long time testing and producing, which maybe affect u normal work!". So the rumours about the stabilization problems of the W8 model might be true after all.

[TurkishDelight]

Thanks for the Information Abby. Surely the Pull with RECI of a machine producer and retail customer is different. They told me yesterday that they wouldn't produce W8 for a while. Seems like the truth is that it takes longer to produce the W8 laser tubes than the others, so they'll sell the few tubes they produce to laser machine producers instead of retail customers. Actually it's the clever choice considering business.

[G.Weike-Abby]

Hi,

Yeah,Maybe it is a clever choice.

RECI Tube sells very fast and hot. We follow them to ask the tubes. But it is wired.everytime we need about 10 pieces or more, they can only send us 4-5....

Abby
G.Weike Laser Factory
[email protected]
[email protected]
Skype:abbylilu
Web:laser engraving machine?laser cutting machine?cutting plotter at G.WeiKe

Thanks for the Information Abby. Surely the Pull with RECI of a machine producer and retail customer is different. They told me yesterday that they wouldn't produce W8 for a while. Seems like the truth is that it takes longer to produce the W8 laser tubes than the others, so they'll sell the few tubes they produce to laser machine producers instead of retail customers. Actually it's the clever choice considering business.

[phylo]

It's not just the focal length that is important , spot size thru the SAME focal length gets smaller if the beam diameter entering it is bigger... so you can get BETTER cutting and engraving with a beam expander/collimator. apart from that , stopping beam divergence will give you more consistent cutting all over the table. These are not cheap devices and good ones can cost $700+.
I have used my 80w Reci to DIRECTLY engrave stainless steel with NO coatings or brush on compounds and I am not using an expander to do it. Here is the evidence....

Just out of curiosity what were the settings you used? I should have my 80W 1290 from Weiki at some point next week and I have some stainless I want to laser.. I tried a 60W epilog with Cermark with not so wonderful results.

I was also under the impression that lasering uncoated stainless was bad for your laser???

Phil
P.S. everybody be prepared for lots more questions once my laser lands as Im probably going to be asking a lot of questions about setup and usage since Im used to using epilog lasers with there very nicely integrated software...

[Rodney Gold]

I was also under the impression that lasering uncoated stainless was bad for your laser???

Why is it bad? - the beam does not scatter off the SS....it marks it black....
I used about 90% power and slow speed like 15mm-25mm sec - using a 40mm lens, 80w Reci

[phylo]

I had heard that doing stainless without a coating would cause scatter.. Maybe its just on lower powered lasers. I know that on the 60watt epilogs even with coating I was having a hard time getting the stainless to mark correctly. The cermark wasnt taking verry well and the edges of the lines were a little blown out (not a problem with focus as I made sure the laser was focused correctly.

Im hoping that the new 80watt I have on the way will also work on electroless nickel plating. I had the same problem with the cermark not marking well and it rubbs off pretty quickly.