What laser cutter to purchase ?

[diracshore]

Hi all,

I have decided I want a laser cutter to play with, a cheap one from China, but it has to perform reliably and take standard CAD file formats as input. I would like to cut acrylic and if possible sheet metal. Thinking $800-2000 USD.

Looking for suggestions, experience, advise.

Thanks !

[mikeselectricstuff]

a cheap one from China,
but it has to perform reliably

Pick one.

[Chet T16]

Is that one of yours still on the go Mike?

[robrenz]

a cheap one from China, but it has to perform reliably

Isn't that an oxymoron? 

[mikeselectricstuff]

Is that one of yours still on the go Mike?

I've hardly used it - the controller is too flaky - there are some files that make it just hang. One of these days I may replace the controller...

[SeanB]

If you don't want it Mike my postbox is available.........

[mikeselectricstuff]

If you don't want it Mike my postbox is available.........

Sorry, collection only...
http://www.ebay.co.uk/itm/200799320943

[SeanB]

Darn it, the postage would be a killer.

[free_electron]

Epilog 40 or epilog 60.
Those work great. Driven directly from Coreldraw or Illustrator or autocad or any other VECTOR based drawing program . Behave like a printer.

they essentially read postscript. rasterised information is engraved. vector information is cut. color information is used to control laser power.

ah , but i see the 500 to 2000 criteria .. it'll be a piece of junk then ...

[Things]

Unfortunately you're not even going to come close to cutting metal with only $2K. Even a decent quality 60W machine (Which won't do metal) will run you about $6K, but note that the decent machines actually have nice integrated controllers with keypads and displays.

You can purchase these controllers seperately from here if you want to mod out a cheaper machine: http://www.lightobject.com/2012-Commercial-DSP-CO2-Laser-Engraving-Cutter-Controller-Support-CorelDraw-AutoCad-P321.aspx

I'm using one for my DIY laser cutter and it works wonders.

At 100W, you're kind of on the verge of being able to cut really thin metal, but you need to be thinking a good 250W+ to do anything serious, and that costs, big time.

[KTP]

This will do what you want.  The seller is taking offers...

http://www.ebay.com/itm/Synrad-Firestar-F201-200-watt-Co2-laser-2005-never-used-Video-252W-measured-/110924181391?pt=LH_DefaultDomain_0&hash=item19d398af8f

(I have several 25 and 50 watt Synrads, but I would trade them all for this dream laser)

[Things]

Note that is just the laser, you would still need an XY table and all associated optics and hardware.

[KTP]

Note that is just the laser, you would still need an XY table and all associated optics and hardware.

Those are the easy parts.  I can do cnc and electronics...building a RF excited slab CO2 laser is beyond any hobbyist.  To my knowledge it has never been done before.  I have thought about trying just to be the first but

[Things]

Yeah, though the laser is the expensive part here, optics and lenses to deal with that kind of power get quite pricey too.

I have seen a few people build CO2 glass tube style lasers, but I think RF excited is beyond most hobbyists.

Some examples & interesting reading: http://laserpointerforums.com/f43/diy-gas-laser-73650.html

http://laserpointerforums.com/f43/co2-build-72448.html

[diracshore]

This guy has made an open source laser cutter, that is self replicating. You can cut a great deal of the parts to create one of these cutters, with the laser cutter itself. So you only need buy the controller and laser components.

http://www.buildlog.net/blog/2011/02/buildlog-net-2-x-laser/

Opinions on the product ?

[mikeselectricstuff]

Lasers that cut sheet metal generally need consumable gas supplies - not sure exactly where the crossover point is, but it is the vicinity of the plastic/metal zone.

[poorchava]

I think that for cutting sheet metal, the most affordable method is CNC Plasma cutter. I think you can purchase a decent quality plasma generator/power supply for under $1k. The CNC fixture is another thing, but if going for minimalistic design it shouldn't exceed $700-1k either (doesn't need exceptional rigidity, unlike mechanical machining).

For cutting acryllic sheets i think conventional milling plotter is still the most cost effective option if you're not planning to use it for high volume production.

Lasers are expensive not only in terms of machinery but also maintenance. All the optics for CO2 systems tend to be rather expensive, and alignment is also a problem.

[FJV]

Whatever is chosen, don't ignore the extra stuff you'll need to buy if you want to use the laser safely.

For instance a laser at an invisible wavelength reflecting of a surface can do considerable harm.

[KTP]

Whatever is chosen, don't ignore the extra stuff you'll need to buy if you want to use the laser safely.

For instance a laser at an invisible wavelength reflecting of a surface can do considerable harm.

Yeah, those polycarbonate goggles that 100% absorb 10,600nm have doubled in price at the local Home Depot recently.  Last I checked they were now $3.00.

[cwalex]

Whatever is chosen, don't ignore the extra stuff you'll need to buy if you want to use the laser safely.

For instance a laser at an invisible wavelength reflecting of a surface can do considerable harm.

Yeah, those polycarbonate goggles that 100% absorb 10,600nm have doubled in price at the local Home Depot recently.  Last I checked they were now $3.00.

Are normal clear plastic safety glasses good enough for protection when using CO2 laser cutters?

[KTP]

Are normal clear plastic safety glasses good enough for protection when using CO2 laser cutters?

Depends on the power of the CO2 laser and how long you stay in the beam while the plastic is melting.

I would want more protection if I were working on a 2000 watt Rofin Sinar, since the beam would burn through the plastic, my eyeball, skull, brain, back of skull, and the wall behind me.  For an unfocused 40 watt laser engraver though, I think the plastic will be good protection, along with whatever protective cover the laser has on it.

You can put a power meter behind one of these goggles and measure how much 10,600nm gets through (before the plastic has melted).  It will not be much if any.  Salt goggles would be a bad idea.

The biggest danger IMO in these Chinese engravers is the HV supply and the water cooling.  I much more like my air cooled RF excited Synrads.

[cwalex]

Thanks for the info. I bought one of these chinese engravers just to see what I can do with it. Here is link to the one I bought http://www.ebay.com.au/itm/230679580259?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_13387wt_1093

The laser tube is under a metal cover that you can lift. Would it be safe to view the tube while its operating if you ware safety glasses?

I have only received the laser cutter, I'm still waiting for the box to arrive with the accessories. I hope the OP doesn't mind me asking questions in his thread.

[KTP]

Thanks for the info. I bought one of these chinese engravers just to see what I can do with it. Here is link to the one I bought http://www.ebay.com.au/itm/230679580259?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_13387wt_1093

The laser tube is under a metal cover that you can lift. Would it be safe to view the tube while its operating if you ware safety glasses?

I have only received the laser cutter, I'm still waiting for the box to arrive with the accessories. I hope the OP doesn't mind me asking questions in his thread.

The safety glasses only protect your eyes...CO2 laser burns are very painful on skin and also could set things on fire.  That being said, if the unit is properly constructed, there should not be much if any stray reflections from the beam path.  You also need to consider bystanders, and make sure they have protective gear.  The high voltage across the tube is potentially deadly, so be very careful.

[cwalex]

cheers, I'll keep the bystanders away if I need to open it up.

[mikeselectricstuff]

I don't think reflections are a serious issue on a small laser cutter - any non- metal will burn instead of reflect,  and the beam is focussed to the cut point, so even if it hits shiny metal, it will be out of focus by the time it gets anywhere.
I don't think the tube bore light is hazardous - none of the 10.6um will get through the glass.