LaserUser.com Forum (formerly RDWorksLab)

thank you very much for the information.

Hi all,
I started building my laser, and I am thinking of using 4 mirrors for the beam to fold it a bit more than the usual 3 mirrors configuration.
I was wondering why I can't find anyone else doing it, is there a big power penalty?

From looking at vendors sites, mirrors seem to have a high efficiency, I see 99% numbers, is that realistic?

thanks for your help

Mirrors are quite efficient when clean and well adjusted- but in practice are just another power robbing component. If you are using a large wattage tube it will not be a big deal. I have found that the longer the beam length between tube and head, the more divergence of the beam you will have.
On a small bed this is not a problem but when you get to a larger bed it can be troublesome. I am working on a 30mm mirror in the cutting head to help alleviate that problem [ but it presents other problems of course].

thank you. I have a 130W tube, but the bed is about 2m x 1m.

I was thinking of putting the tube on the gantry, but I'm walking back from that, it's too much mass.