Ablation

[steveUK]

Hi All,
Completed building a 4 foot by 8 foot X Y table recently. I am presently building a Q switched YAG laser to attach to the table. I wish to use this for ablation. Probably mainly on stainless steel. Started to worry about the fumes given off by this sort of process. Am I going one step too far for a hobby machine? Any advise on the sensibility of this and control of the fumes would be appreciated.

Steve.

[HuFlungDung]

Hmm, first lets find out what ablation is

1. Surgical excision or amputation of a body part or tissue.
2. The erosive processes by which a glacier is reduced.
3. Aerospace. The dissipation of heat generated by atmospheric friction, especially in the atmospheric reentry of a spacecraft or missile, by means of a melting heat
shield.

Okay, so under condition 1, it might smell like burning meat, condition 2, it should just be steam, and condition 3, the whole darn thing is vaporized.

Ya, I'd be concerned about the fumes. I'd do some research to see how to collect and reduce the fumes.

[steveUK]

An appropriate definition for ablation. May be found at http://www.me.mtu.edu/~microweb/chap4/ch4-2.htm

and is, quote:- "Ablation, in the broadest sense, is removal of material because of the incident light"

Sadly however, judging from the number of responses to this thread, there does not seem to be a lot of hobby CNC'ers Ablating, and I thought everybody was doing it!

[scottsss]

Just look at it cost wise, it is out of reach for the hobbyest. I would like to build a laser cutting system but the cost of the laser is what is holding me back. I've not seen any good deals on ebay. Though I look time to time. Also most of the units that will do a decent job in metal are not something I can just load in the back on my pickup truck and hall home.

I have been toying with the idea of ECM. Though if I had a standard shape round or square that I could plung errode metal in the shape I want. Think that would be cheaper to set up then a laser. Though right now it is just an idea at the back of my head sort of bouncing around. Though it would not be a quick process.

[steveUK]

The laser I am finishing building, will have cost around $3000, not cheap I agree. However I should have one heck of a tool for my $s when it is complete. Hopefully I will be able to recover some of the costs by doing a few small jobs with it, that can't be easily managed with conventional kit. Such as cutting accurate shapes in ceramics.

[Graham S]

How powerful is your laser going to be (if it works)??

I am considering a homebuilt flowing gas laser, much easier and cheaper. Apparently (according to Sams Laser FAQ's) they just want to lase.

You probably just need some extraction.

Graham

p.s. Isn't this a daft forum for this topic to be moved to, who actually checks out the safety forum, good job there is a redirect in the general forum.

[scottsss]

Post some pictures of the finished laser system. I'd be interested in seeing it and the work your capable of doing with it.

[steveUK]

Hi Graham,

Due to the laser being Q Switched it will develop in excess of 3 Mega joules per pulse, at 26 pulses a second.

Steve.

[steveUK]

Scott,

Thanks for your interest, will definitely post some pics when completed. Have also got a second laser on the go, which I hope to use for engraving this one is only 80 watts continuous (a baby). This is the most likely to get completed first. The CNC X Y table is completed and works, has been tried out with a cheap Plasma cutter, but still scratching my head a bit at how to deliver the laser beam.

Steve.

[ImanCarrot]

Extraction yes! definately... apart from the safety aspects, your beam may be incident through ablated (vaporised) substrate and hence be slightly weaker (like going through clouds).. it may re/ defocus the beam.. Extract axtract extract.