Suggestions for cutting ABS Plastic? and other newbie questions

[spyderrobotics]

I am new to this forum and am looking into cutting vent holes, lcd cutouts, ect in abs plastic that is 3-4mm thick. Right now we are using a couple of maxnc desktop cnc machines but are trying to get away from the noise and the cuts will leave hairs on the edges occasionaly that we have to exacto off. Will laser cutters leave a clean edge without melting/distorting? What power laser cutter should I be looking at for this application?

I see alot of people's posts not being satasfied with the chinese laser cutters but looking at the american ones they seem way out of my price range. Right now I am only needing to cut and not engrave so much. Any suggestions on a decent inexpensive machine?

I'd like to see the results of one of my abs plates being cut. Nothing special, just have a square cut out of it and maybe a screw hole. Anybody with a laser willing to give it a shot for some beer money?

Thanks in advance for any advice you can give me.

Dion Brewington

[zax15uk]

Dion,

Laser cutting ABS may leave a slight radius on the front side. If you need a nice sharp edge you may want to reverse cut. Unlike Acrylic which vaporizes the ABS melts and decomposes, but this is not to say the finish won't be acceptable. The other slight difference is that depending on lens focal length the edge may be slightly angled, but on 3-4mm you won't notice.

It will be important to use air assist, and I've also noticed some laser cut ABS can smell bad (especially the textured, harder variety).

The Chinese systems are an excellent buy in my opinion, and suited to a small business where you are willing to invest some time to save cost but they aren't for everyone.

I would recommend a 60W system, although 40W would be ok depending on model. What is your budget? (it's ok... I am not trying to sell you anything)

Zax.

[spyderrobotics]

For what we do right now everything is just square or circle cuts in the abs. Nothing fancy. The cnc has a 1/8" bit in it that drops in and out to create some screw holes as well that our 6-32 screws thread into. However, I would like the possibility of doing additional projects like engraving text, ect in the future. I've read about the smell and realize I will have to vent to the outside of the workshop. I've read about the air assist and it looked like most machines come with that built in and include a pump otherwise we do have a 6 gallon compressor on site that I could attach a regulator to assuming the air assist won't keep it running all day. I saw the the chinese ones are watercooled and I am no stranger to that concept as thats all I run on my PC cooling so I have plenty of radiators/fans, tubing, and pump experience. Somewhere I read that the american ones use a different type of cooling but it didn't specify.

My budget doesn't really exist. But I am trying to keep it under $5K which for american made puts me in the used catagory which concerns me. I was looking at 50-60W systems. Some of the post say that a chinese 40w may actually put out much less and am also concerned about that. Plus I'd have to find someone selling the chinese ones reasonably in the U.S. because I won't take the risk of importing one myself.

[zax15uk]

Most of the US machines use a metal 'tube' with either forced air cooling or recirculating coolant. These are more reliable and can be refilled, but for the cost you could buy a new Chinese tube. It's a case of pay now, or pay later.

OK, well $5k will get you a Chinese system in the 60W range (direct from China) but most of the US resellers will be charging a bit more.

If you don't want to deal with the import and added problems (a wise decision if you haven't done imports before) then I'd give these folks a shout.

http://www.scottware.net/home_lasers.html
http://www.legacylasers.com/
http://www.mbkpinternational.com/laser_engravers.htm

If you do decide to look at import, let me know. There isn't really any risk, just pot holes you need to be aware of so there aren't any surprises.

Back to your application for a moment, is there any possibility you could switch over to Acrylic? It is much easier to cut, produces a great edge and engraving looks great. You could reverse engrave and fill clear then coat the back for an even better looking product. ABS is more resistant to cracking though - so probably has benefits in that area.

Zax.