[hastran]

I was thinking about getting a small desktop laser cutter for cutting small parts out of plastic sheet for model making. The cheapest ones I can find in the UK are around £2000 which is out of my budget at the moment but I've also seen cheap ones from china on ebay for under £300 are these any good. Even if these are suitable for what I need I'm a bit dubious of buying from China; anybody had any experience of this?

Thanks in asdvance.

Brian Tayor
smartmodels.co.uk

[Fred27]

I decided to play around with a laser and went for one of the eBay DC-K40 lasers. It works out about £500 including delivery. The core of the machine is sound but you will probably need to reattach the bits that fell off during shipping. Build quality is poor. The software is awful so I immediately replaced the control board in mine with one from Chriscircuits.com and used Mach3 for control.

If you're happy to tinker and consider it almost as a kit of parts then it's great value. If you want a machine that's perfect straight out of the box then it's not for you.

[hastran]

No I'm not one for tinkering with electronics I rather have something that works out of the box and is reliable.

[epilotdk]

In that case you need to spend around £2000 and will have to import from China to get it at that price.

[Gweikelasers]

Even in china, a real entry level laser cutter with some optional accessories is around used 2000. EBay cheaper ones are not good ones. You can find many posts here about that.

[TurbineJesse]

I gotta agree... in your budget, you will not find a "hands-off" laser system, no way. They will all require (to some extent), work. Just aligning the thing will be very much hands-on. Let alone trouble shooting problems (there will always be some kind of issues along the way), changing out mirrors, lenses, power supply, motors, etc. If you want to get a laser, be prepared to be hands-on, or outsource the work to someone else. Jut reality.

[Bec Weir]

Does styrene cut well with a laser?
Every time I have tried (on my old FSE 40w mind you) the quality of the cut has been less than ideal.

[hastran]

Thanks everyone for your advise. I guess just have to wait until I have a bigger budget.

[Rodney Gold]

Styrene cuts ok , we use it for stencils , similar to ABS , It does however release a white powder which gets all over the machine innards.
I have even cut the expanded stuff (the packaging material stuff) up to 2" thick , although the width of cut is large , OK for big letters etc.

[epilotdk]

It's OK but not great. The edge leaves a little to be desired. Plus of course it stinks! Even with good extraction the smell lingers in the machine.

[cinematic2]

If you respect your and your co-workers health and live you should NEVER, EVER cut styrene with the laser.

Agency for Toxic Substances and Disease Registry (ATSDR) say it is a poison.

Read about styrene.

Read Health effects under:
Styrene - Wikipedia, the free encyclopedia

Styrene is regarded as a "hazardous chemical", especially in case of eye contact, but also in case of skin contact, of ingestion and of inhalation, according to several sources. Styrene is largely metabolized into styrene oxide in humans, resulting from oxidation by cytochrome P450. styrene oxide is considered toxic, mutagenic, and possibly carcinogenic. Styrene oxide is subsequently hydrolyzed in vivo to styrene glycol by the enzyme epoxide hydrolase. The U.S. Environmental Protection Agency (EPA) has described styrene to be "a suspected toxin to the gastrointestinal tract, kidney, and respiratory system, among others." On 10 June 2011, the U.S. National Toxicology Program has described styrene as "reasonably anticipated to be a human carcinogen". However, a STATS author describes a review that was done on scientific literature and concluded that "The available epidemiologic evidence does not support a causal relationship between styrene exposure and any type of human cancer.". Despite this claim, work has been done by Danish researchers to investigate the relationship between occupational exposure to styrene and cancer. They concluded, "The findings have to be interpreted with caution, due to the company based exposure assessment, but the possible association between exposures in the reinforced plastics industry, mainly styrene, and degenerative disorders of the nervous system and pancreatic cancer, deserves attention." The Danish EPA recently concluded that the styrene data do not support a cancer concern for styrene.

The U.S. EPA does not have a cancer classification for styrene, but currently is evaluating styrene's cancer-causing potential through its EPA|Integrated Risk Information System (IRIS) program. The U.S. National Toxicology Program of the U.S. Department of Health and Human Services also currently is evaluating styrene's potential toxicity To date, no regulatory body anywhere in the world has classified styrene as a known human carcinogen, although several refer to it in various contexts as a possible or potential human carcinogen. The International Agency for Research on Cancer considers styrene to be "possibly carcinogenic to humans". Chronic exposure to styrene leads to tiredness/lethargy, memory deficits, headaches and vertigo.

[Exsecratio]

Its a level 3 potential carciniogen.....

Along with Printing ink, Bitumen (road tar) , Common leaf Tea, Marzipan, Doritos, Citrus Marmalade, Swiss Rolls , Lucozade and bloody Bread Crumbs!! (E110 Colourant)

More dangerous by one full level (Level 2B)is Caffeine, so please stop drinking coffee as it's toxicity is far above that of styrene (polystyerene) Caffiene's LD50 (median lethal dose) is 192Mg per Kg (or around 200 cups).

So please ensure before working with the styrene family you carefully dispose of all coffee in your house

[wontpontificate]

To echo the above, I don't think you're going to find any laser that is entirely tweak free, whether you buy a £20k Epilog, or a £500 K40. At the very least, you're going to be tweaking mirror alignment the first time you set it up, and plumbing your cooling and fume extraction.

The K40 uses a controller board which is tied to the software -- generally NewlyDraw, NewlySeal, or MoshiDraw. I don't believe that any of these are totally unusable, but they're buggy, badly translated, and have annoying limitations (I believe that vector cutting is still oddly supported, if supported at all). You'll probably wind up giving yourself grey hair, trying to make it do what you want it to. It also uses a hardware copy-protection USB dongle, which has been known to fail, leaving users up the creek, since it costs more than it should to get a replacement.

The software and the controller board are married in such a way as prevents you from using any other software with said controller board. In addition to that, the boards can be unreliable, and are known for letting out the magic smoke at very inconvenient moments.

Thankfully, the K40 (and laser cutters in general) aren't really complicated machines from the standpoint of replacing electronics, and there are a number of options open to you for swapping out the annoying and/or dead controller hardware, such that someone with very limited electronics experience could, with some care, rebuild their machine in a weekend.

Unfortunately though, this can add up in a hurry, and your £300 Laser cutter, delivered for £500, has become a £1000 machine, one that you've had to tweak to get to this point.

From here, you have a working machine, but then you'll probably want to hook up an air assist, replace the cutting bed with something more suited for cutting plastic sheet, possibly adding a Z axis to it in order to get the best focus, etc. etc. It all adds up in a hurry.

There are a number of threads on here documenting both the strengths and weaknesses of the K40 machine, as well as a list of recommended ebay sellers, who possibly won't fly by night on you.

I considered one for a while (still am eyeballing, really). The physical size of the machine really appeals to me, but after some research, it doesn't seem like the best value in the world. Recently, I've been looking at the G350/3050/etc. series machines, as they tend to include DSP control (better software), adjustable table height, air assist, larger cutting area, and generally seem to be a better "value" overall. They still require some tweaking, but again, pretty much any model laser will require a fair bit of tweaking to get it making smoke as efficiently as possible.

[epilotdk]

You must have good air assist and the cheap K-40's don't come with that.