[rustyolddo]

Need something that can engrave metal similar to electro etching. It's not cost effective nor easy to make stencils for one-of jobs. Currently using a high speed spindle and I've used a vibratory engraver in a CNC application.

I see a number of fiber laser diodes listed on Ebay. What would be ideal, and I don't know if such an animal exists, would be a laser device where the head was connected to the laser via fiber. The head would be mounted in place of the CNC spindle and you would drive the machine using regular CAM software using M codes and Z retracts to turn the laser on & off.

Is something like this possible and cost effective using surplus parts?

[Tweakie]

If you already have the CNC then it is quite feasable to do and not that expensive I would think. You need a laser operating around the 1064nm range for marking metals and you also need to be clear on the various terminology formats. Fiber lasers are typically beyond the financial reach of the home constructor but diode lasers which are connected with a fiber optics beam delivery system are relatively cheap. The YAG stuff is also cheap but tends to be large in size and the triggering components (Q switch etc.) quite complicated to use so the diode is probably the best bet.
I fitted a CO2 laser head to my existing CNC (no good for marking metals, wrong wavelength) quite a lot of work but brilliant now it is all working Tweakie.CNC - CO2 Laser Cutting.

Tweakie.

[rustyolddo]

... diode lasers which are connected with a fiber optics beam delivery system are relatively cheap. The YAG stuff is also cheap but tends to be large in size and the triggering components (Q switch etc.) quite complicated to use so the diode is probably the best bet.
I fitted a CO2 laser head to my existing CNC (no good for marking metals, wrong wavelength) quite a lot of work but brilliant now it is all working Tweakie.CNC - CO2 Laser Cutting.

Tweakie.

Thanks for the link to your website, very informative especially the discussion on how you used the Z direction pin to control the laser. I have two bench top machines that I converted & run Mach3 on including a 4th axis. My biggest lack of knowledge is in the laser field. Especially when it comes to the diode types & what needed to drive them & the optics. Power supplies are no problem, I've built many. I understand I need 1064nm for metal, a lot of the diode lasers with a fiber optic are in the 808nm range. I need to keep digging on this subject.

I think in the mean time, I might have a go at the low power LED laser, it would be handy for making the occasional gasket, never gave it much thought until I saw your application.

--R

[Tweakie]

Rusty,

For the low power laser you need at least 150mW (more preferably) and even then you will be very limited in material thickness that can be cut but it's a fun project and lots to learn.
Make sure you wear the appropriate eye protection (the beam bounces off just about everything).

Tweakie.

[mcphill]

The YAG stuff is also cheap ...

Can you possibly share some sources? Or what do you consider "cheap"?

[Tweakie]

You perhaps need to check with ebay in your own country on a daily basis to see what comes up, the real bargains don't last long.
In the UK something like this is perhaps worth a shot YAG LASER FOR CNC | eBay UK

Unfortunately everybody's definition of "cheap" will be different - for me it is something that I can afford (hundreds rather than thousands).

Tweakie.