Opinions on the REALLY cheap Chinese cutters for hobby use?

[mikeselectricstuff]

Idly browsing Ebay I can't believe how cheap these are, e.g.
http://cgi.ebay.co.uk/CO2-LASER-ENGRAVI ... 3cae5e16f3
Just under GBP600 (US$1K) delivered. This is so cheap I'm very tempted to buy myself a new toy - the only definite application I'd have is cutting paste stencils, but I'm sure I'd find other fun things to do with it.

So just how crappy or otherwise are these in practice..? Is laser tube life what they say? How good is the focus tracking across the bed?
What's the spot size like? What's the motion control like - do curves come out OK? How well do they stay aligned?
I've seen the mirror mounts on a more expensive one close-up, and even those were pretty crude, and I have no doubt initial alignment would be somewhat fiddly, but once set up, how good/bad are they?
Not too bothered by poor extraction/cooling as these are easily fixed/replaced, as adding air assist.

I'd be interested in any comments from people who've used/owned one.
Feedback seems good, and I don't think I've ever seen anyone selling a used one.

[tsaylor]

I'm also looking for this exact info. At Pumping Station: One we've been paralyzed by the massive cost of Epilog lasers and haven't gotten any closer to getting one in the last year. We're talking now about buying one of these to bootstrap ourselves into lasering and want to know what we're giving up by going cheap.

[250 Coupe]

Here's my input,
I don't see a way to focus the laser, that means you have to get the object at the focal point by setting it on stuff and hoping it stays there. I could be wrong here.

The ventilation fan is a bathroom fan that is probably not sufficient to evacuate heavy smoke but would work fine for things that don't smoke much like ipods and laptops.

Water cooled! With an aquarium pump! In a bowl of water!

Pictures in user manual taken with cheap cell phone camera.

"Test switch" may or may not be a red dot, I don't think so and that's a very handy thing to have. After reading the manual, it may be for adjusting power output.

The software may be proprietary so you can't use files from other sources. It looks like it's pixel based so no vector graphics.

It requires XP or 2000 and a parallel port. Which could be a good thing.

On the other hand, it does look a bit sturdier than the laser linked from ebay a few months ago.

If links to outside forums are allowed, look here for a 91 page thread on this machine, it appears to have been around since 2005.
http://www.cnczone.com/forums/laser_eng ... raver.html

It could be a good entry level machine if you have no plans to do vector, don't want to engrave anything taller than 2.8 inches and don't need it done quickly.

Michael

[mikeselectricstuff]

AFAIUI you can get it with either 'newlydraw' or 'newlyshield' software, the former does cutting, and I believe it imports DXF, the latter engraving.

If it's not been done yet, it can't be long before someone does some alternative improved software to drive these...

Aquarium pump - why not? It does the job, and again, this is something you have the choice to improve if you want to. Ditto bathroom fan.

[250 Coupe]

It looks like newlydraw will do both vector and raster so my concern about that is not valid, newlyshield appears to be for rubber stamps.

Searching for "K40 laser engraving" brings up a ton of hits, most of which say it runs with Corel Draw.

Folks on the CNC forums are already talking about swapping out the driver board and motors for open source which would open up a ton of options but require a lot of tinkering.

Water cooling turns me off as condensation inside the machine is major concern. On the other hand, it's cheaper than the 9 4" fans on my Epilog.

Michael

[mikeselectricstuff]

co2 lasers are always watercooled - it's a sealed circuit, and as the water would start at room temp there shouldn't be any condensation.
I can see a nice opportunity here - the newlyseal (not shield, sorry!) and draw software appears to be dongled, and the cheaper units only run on a parallel port.
If someone were to do a replacement USB controller board & software, I'm sure you could get the Chinese to sell you the machines without their controller board, and you'd probably end up with an overall better product for the same or less total money.
Useful additions would be software controllable laser power,input for water flow & temp sensor, and maybe a laser power sensor for closed-loop power control - the latter could just be a thermistor on a heatsink at one corner of the bed.
Seems an ideal candidate for an OSHW project - the hardware wouldn't be very difficult - AVR or small ARM with USB, and some stepper drivers.

The question is how good or otherwise are the underlying mechanics and optics, in terms of what ultimate accuracy is achievable.

[250 Coupe]

co2 lasers are always watercooled - it's a sealed circuit, and as the water would start at room temp there shouldn't be any condensation.

Except for every Epilog laser under 100 watts, and maybe even those since they were developing air cooled 100 watt units when I bought 70 watt machine in 2002. Oh, and all Universal Laser System machines.

The optics and general construction of the machine looks good. Things are well built, solidly anchored and fully adjustable. They seem to have been around for quite awhile and that won't happen with poorly built machines.

Michael

[mikeselectricstuff]

OK so curiosity got the better of me & I ordered one :
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0508865528

I chose this seller as they seem to specialise in laser stuff - several others, especially the hong Kong ones sold all sorts of completely random stuff.
GBP720 delivered, and only £11 VAT/duty as they declared it as 'parts' with a value of GBP50
Arrived in good condition in 1 week. Hooked up and away it went - no need to tweak optics or anything. Cut a very useable looking 75u polyester paste stencil first time - looks like it may be able to do 0.5mm pitch with careful tweaking of power and material.
It came with 'newlyseal' software which does raster-scanm ode only - the ebay listing stated NewlyDraw and the supplier apologised and has said they will be sending the right software.
Will report on progress after some more playing....

[mikeselectricstuff]

Some more info here : http://electricstuff.co.uk/lasercutter.html

Hey you can even make components with this thing...

[Philly]

What material is that mike, and where do you get the polyester for the stencils?

[mikeselectricstuff]

It's red 1.5mm acrylic. I got some film from ebay, and some thinner 75u stuff from Stencil Warehouse. You need the thinner stuff for finer pitch.

[250 Coupe]

That's some pretty darn cool stuff you've got there. I like it.

I cruised your site and saw the mercury arc rectifiers. The steel mill I worked at used them until just before I was hired in 1986 and switched them out for 2 slaved 1200 amp 250VDC silicon units. I never got to see the mercury units and got stuck making the silicon junk stay sync'd and running.

Michael