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Thread: Recommendations on a higher powered laser-180watt or so- Chinese?

  1. #1

    Recommendations on a higher powered laser-180watt or so- Chinese?

    HI Folks,
    our Chinese Goldenlaser (130watt) has been trundling along and I'm happy with it- but I had a bed of 2" high letters to cut from 20mm cast acrylic, and at 1.2mm per second, it ran for 16 hours and still not finished. I've used E-cut's 'extend nodes' option so the start and end of the path are off the letter, and I set overlap at about half the material thickness to give the beam time to get through the acrylic to the bottom, before it reaches the real letter.
    I can cut at about 1.5mm/sec, but the bottom edges of the letters are a bit oddly shaped after the top turns a corner before the bottom has. Slowing it a tad has helped a lot.

    I've cut 25mm acrylic at a pinch, just to see if it was capable - but fitting it under the air nozzle was a test - speed about 0.4mm/sec, and power settings 100% max, 98% min in the software - which translates at 21-22mA at the power supply- or about 80% of the tube's max recommended power of 28-30mA.

    I've instead, routed the 25mm letters, but there are times the insides and gaps of R, A etc can't really fit an endmill without an ordeal or risk of breaking something after running a path at several successive depths...

    I'm keen to read ideas and opinions for a chineesy laser in the 180watt department, or feedback on speeds and power settings others are using for thicker acrylic.
    I still have heaps more 20mm letters to cut, including a couple of days cutting small letters from 15mm opal acrylic also. I've also masered 25mm by lasering 20mm and gluing a 4.5mm lasered face on top - 24.5mm is near enough to the inch for most spec's by architects.

    Thanks!

    PS I'm not out to spend money on the great American made ones, sadly!
    Last edited by Ian Stewart-Koster; 12-15-2017 at 4:33 AM. Reason: typo
    Best wishes,
    Ian



    ULS M-300, 55w made 2002 with rotary. Goldenlaser 130 watt, 1300x700 made 2011.
    Flat bed 2500x1300 150/90watt 2 tube laser, 2018 model.
    Esab router, 1989, 4.5 x 2.0 m, conv. to Tekcel, and modded a 2nd time.
    HP L260-60". Roland PNC-1410. Mimaki GC-130 SU.
    Screenprinting carousel 6x4 and 7x4 ft 1-arm bandit vac table.
    Corel Draw X3, Illy, Indesign & Photoshop CS2 & CS5, Enroute 4
    Pencil, paper, paintbrush, airbrush & dagger-liners & assorted other stuff.

  2. #2
    Bit of a long winded answer but here goes

    Cutting thick materials over 10mm or so with a DC tube tends to run on the inverse square law. If you double the power you only really add 50% to the speed or to double the speed you need 4x the power. This of course stops after a given point as the material becomes more subject to induced heat causing problems rather than the actual speed.

    Lasers in general cut with a drag behind system, although it looks like the top of the material and bottom are being cut at the same time, they actually aren't, the closer you get to the limit of material thickness the more noticeable it becomes in some cases with 2mm drag behind not being unusual.

    The problem you will have Ian is two fold, the higher power tube will cost nearly twice as much but only give you around a 30% increase in speed as well as requiring a lot more input power and better cooling. (DC lasers ar at best 15% point efficient) as well as issues of getting a straight egde. YTou would need to move to a focal length of 6 - 8 inches to get a reasonable depth of field but tat the same time that would reduce power density by a large factor (so rendering the tube power increase moot)

    Acrylic is an unusual material in that it acts as a waveguide so getting a straight cut over a larger distance than you can in say wood is easier but once you start hitting 15mm thick things start to get troublesome (as you are finding) mainly due to heat.

    To be honest, a 180 is false economy, they can be twitchy and won't let you make any cooling mistakes, if you really do need to cut anything over 15mm with decent speed and quality you really need to be thinking 350 to 500 watts (and that is serious $$$$$'s)

    A 180 (210 peak) will mean a new power supply and they aren't cheap at that power level to get a reliable one along with a CW5200 or better chiller.

    I've blown up 3 tubes in that class over the last year and it gets expensive

    My honest counsel? stick with the 130 but run it nearer it's maximum current or go with a router
    No longer an active member so messages may not be replied to.

  3. #3
    Thanks a lot, Dave, I appreciate the reply-and long winded it wasn't really!

    If I were to run the 130 at a higher current, I'd have to go poking inside the tube power supply to see if there was a potentiomenet that might have been tweaked to limit the current to 80% of max tube preference, when the software is set for 100%... because that's where we are at the moment.

    Yes, it's very clear, on thicker stuff, even with the 4" FL lens, that the cut beam leaves an edge like the bow of a ship, or trailing like a shopping trolley jockey-wheel.
    Before I was using the extend-nodes option I'd have to set the path to overlap, and I'd make the overlap length about 2/3 of the material thickness, to ensure we didn't have little uncut tags of background at the bottom still holding it all together.
    Hence I slowed it down a lot to get a more vertical edge especially in the corners- or else I have to trim and tidy things up with the bobbin sander or disc sander - which defies some of the benefits of a nice shiny lasered edge in the first place.

    I've routed enough in time, big and small, and have tweaked the router to even cut me nice little 5/16" high letters in 10mm acrylic which people tried to tell me was impossible, but which I did super-slowly with a 1/16 cutter, and occasionally finer ones, but since getting the lasers I have no intentions of routing unnecessary things, when the laser does a neater job.

    But up around the 20 to 30mm thick is where work is currently plonking us... The 50 and 75mm thick stuff we fabricate hollow.
    25mm is borderline... and 20mm the laser is good at, but spending 2 days babysitting it and still not beng finished, isn't terribly exciting, and you have to watch it does not set fire to the acrylic underneath... I'm tempted to pipe-in the big air compressor for more air-assist than the little pump gives.

    Thanks for the maths lesson- I didn't realise a power increase of 50w from 130 to 180 would be about as good as ineffective due to other losses.(or relatively negligible increase, rather than say a 35% speed improvement.

    So... what sort of laser are others here cutting 3/4" or 1" acrylic with, or am I the odd one out with these sizes?

    I've been looking at a spare power supply for the 130 Goldenlaser... the other day it stopped working, but after a brief panic, and a cup of tea to think about it clearly, it was the lid's magnet that had shifted and stopped the PSU from firing the tube. (we keep a magnet on the sensor, and usually have the lid open)

    What caused your 3 tubes to blow? Here in Australia a replacement 130W RECI is not cheap either - in the low $2k range.

    Is a 260watt unit more feasible, or as you say- go back to the router instead- but have you any recommendations on the larger power sizes?

    (I already have a CW5200 chiller.)

    Thanks again.
    Last edited by Ian Stewart-Koster; 12-15-2017 at 9:45 AM. Reason: typo
    Best wishes,
    Ian



    ULS M-300, 55w made 2002 with rotary. Goldenlaser 130 watt, 1300x700 made 2011.
    Flat bed 2500x1300 150/90watt 2 tube laser, 2018 model.
    Esab router, 1989, 4.5 x 2.0 m, conv. to Tekcel, and modded a 2nd time.
    HP L260-60". Roland PNC-1410. Mimaki GC-130 SU.
    Screenprinting carousel 6x4 and 7x4 ft 1-arm bandit vac table.
    Corel Draw X3, Illy, Indesign & Photoshop CS2 & CS5, Enroute 4
    Pencil, paper, paintbrush, airbrush & dagger-liners & assorted other stuff.

  4. #4
    What caused your 3 tubes to blow? Here in Australia a replacement 130W RECI is not cheap either - in the low $2k range.
    One went because I knocked the chiller on/off with my knee blew the end off the tube when the water flashed to steam in the hot end the other two were used for engraving quite a bit and that stresses them to the max with a 37 - 38mA starting spike...engraving with anything over an 80 watt does a pretty good job of killing DC tubes due to the much higher percentage ignition current they require over the run current. At $3,000 US per tube it gets expensive really quick

    Big DC's are a nightmare, in effect you have two ways of doing it, either using a beam combined 130 pair to get a genuine 260 watt beam (two chillers and two PSU's) but even those can be a nightmare if there is any imbalance in the polarisation of the two tubes. You can buy combined pair units off the shelf up to 300 watts at around $6,000 US

    The other option is the Big EFR's, they do an F220 that in effect is a single tube with two internal cavities to get the same effect from the combined beams. I have to be honest though, even though I like EFR I have heard plenty of horror stories about the fatboy folded resonator tubes. They run really hot at high currents (40mA run with a 45,000kV source) and of the 4 I know of that folks had, all four died inside 3 months, some with a rather big bang

    DC tubes, affordable one's really don't scale well in higher powers until you start looking at very high end like Coherant ($2,000 US for a 45 watt) or The SLC 220 from GSI (at $22,000), the reason the tubes like that are expensive is the technical aspects of building them to be reliable, hence why cheap imitations never really last long.

    Is a 260watt unit more feasible, or as you say- go back to the router instead- but have you any recommendations on the larger power sizes?
    Put it this way, I have a 7,500 watt CO2 sat next to me (a big Mitsubishi metal cutter) that will rip through 20mm steel sheet like butter but still makes an unholy mess of 20 mm acrylic , with 25mm it just tends to set it on fire

    The problem at those thicknesses isn't the power of the laser, it's heat in the material, the core (mid point between the top surface and the underside) traps that energy causing meltback and wobbles generally leading to it either having to be run dog slow or looking dreadful. I hear stories every day when I say things like the above on Facebook of "Oh I cut 30mm acrylic every day with my 60 watt" and it's probably true as even a 1 watt BluRay will cut it eventually but I'm no great fan of having cycle times in days or selling poor quality crap which is the net result in all cases (unless somebody manages to change the laws of physics)

    I've always maintained that 15mm + acrylic and 12mm+ MDF etc is about the sensible limit for DC Lasers of any power before you start going into decent RF units and even then the gains simply don't stack up when you consider the cost of the laser resonators, 18mm MDF is about the limit for a good quality 300+ watt RF after that everything goes black due to the old heat core problem.

    On the air issue, it's actually counter productive with acrylic, the problem is you are forcing ablated acrylic particles back into the cut (or even acrylic gasses that have been disassociated) and that often leads to a frosty edge and really funky side walls due to the irregular cooling it causes, this is part is down to the band gap energy of the materials, once you move into a photothermal cut rather than a photochemical (based on photon energy) things start to go very wrong and heat becomes a big issue.

    Personally, my advice would be go to the router for anything acrylic 15mm and over as a CO2 laser at that point is really the wrong tool for the job. It can be done however you can also dig a hole in your garden with a nuclear weapon...it's just not a good idea
    No longer an active member so messages may not be replied to.

  5. #5
    Right-ho, thanks a lot for the education, Dave... I'm not sure about nucelar weapons but we have shovels, an 18 HP & a 40 HP tractor capable of helping the holes get deeper... but dirt is a bit softer than 25mm acrylic.

    I've seen a couple of jobs lasered in 20mm clear that were beautifully done, even by my standards... I have no idea who did them, as they were in signs we pulled down to replace, and the company had long gone bust.
    (I'm also certain they were lasered, not routed, sanded and flame polished - I've trod those alternate paths often enough to know the difference!)


    Thanks again - and does no one else here tackle the thicker acrylic?

    I'll still try & improve the air assist's pressure a bit. I get tired of occasional charring underneath, and the MP468 self-adhesive tape often either does not cut through, or catches fire, too...
    Best wishes,
    Ian



    ULS M-300, 55w made 2002 with rotary. Goldenlaser 130 watt, 1300x700 made 2011.
    Flat bed 2500x1300 150/90watt 2 tube laser, 2018 model.
    Esab router, 1989, 4.5 x 2.0 m, conv. to Tekcel, and modded a 2nd time.
    HP L260-60". Roland PNC-1410. Mimaki GC-130 SU.
    Screenprinting carousel 6x4 and 7x4 ft 1-arm bandit vac table.
    Corel Draw X3, Illy, Indesign & Photoshop CS2 & CS5, Enroute 4
    Pencil, paper, paintbrush, airbrush & dagger-liners & assorted other stuff.

  6. #6
    This is probably very wrong, but I'll say it anyway: Waterjet?
    ========================================
    ELEVEN - rotary cutter tool machines
    FOUR - CO2 lasers
    THREE - fiber lasers
    ONE - vinyl cutter
    CASmate, Corel, Gravostyle


  7. #7
    I've seen a couple of jobs lasered in 20mm clear
    Higher powered RF with a long focal length lens will do that but it will be slow

    This is probably very wrong, but I'll say it anyway: Waterjet?
    No idea Kev, I got rid of mine ages ago but I guess it might work if you don't use any abrasive and just use raw water pressure, gets rid of the heat problem at least
    No longer an active member so messages may not be replied to.

  8. #8
    Join Date
    Nov 2012
    Location
    Brisbane, Australia
    Posts
    284
    Quote Originally Posted by Ian Stewart-Koster View Post

    Is a 260watt unit more feasible, or as you say- go back to the router instead- but have you any recommendations on the larger power sizes?

    (I already have a CW5200 chiller.)

    Thanks again.
    I have a 300W Yongli(dlt-300) If you want I can try to do a thick acrylic and see how fast & clean it is cutting with 300W power.

    I recon it will be about 6-8mm/s for 20mm thickness. Definitely much faster than 1.5mm/s.
    Please let me know if you want me to try as I need to find a 20mm acrylic piece in my shop first.

    I can tell you that it can cut though 6mm clear acrylic at 25mm/s so it is a quite powerfull tube.
    GCC Spirit GX Pro 100W(synrad)
    Laserlife Ezlaser LCW 300W(Yongli DLT-300)

  9. #9
    Thanks, Mike, it'd be interesting to know, but not critical.
    I put some 25mm acrylic under ours 2 days ago, and it did an acceptable job at 1mm per second, 100% power in the software (80% ot tube max current).

    Oddly I got some better cuts at some speeds in thinner (15mm) acrylic when I lowered the minimum setting a lot, but nothing I could establish as a regular pattern.

    Cutting 6mm is no burden- even our 45w ULS is happy with that, though your 25mm/s is quick! From memory we do it at about 8mm/s in the 130w machine.

    Thanks for the reply.
    Best wishes,
    Ian



    ULS M-300, 55w made 2002 with rotary. Goldenlaser 130 watt, 1300x700 made 2011.
    Flat bed 2500x1300 150/90watt 2 tube laser, 2018 model.
    Esab router, 1989, 4.5 x 2.0 m, conv. to Tekcel, and modded a 2nd time.
    HP L260-60". Roland PNC-1410. Mimaki GC-130 SU.
    Screenprinting carousel 6x4 and 7x4 ft 1-arm bandit vac table.
    Corel Draw X3, Illy, Indesign & Photoshop CS2 & CS5, Enroute 4
    Pencil, paper, paintbrush, airbrush & dagger-liners & assorted other stuff.

  10. #10
    Join Date
    Oct 2014
    Location
    Cleveland OH
    Posts
    192
    Hey Ian,

    What type of router are you using ?? What type of bits ??
    We almost bought a Large laser system for our small 1/2" parts but after talking to a few industry experts and visiting a local company, We found it possible to do it all on our Cnc routers. The laser we were looking at was 3x the cost of our current Router setup so you can see the draw back we faced. In all we found with the right bits, settings and a more powerful vacuum we were able to achieve what we needed for a fraction of the price. Now we can afford to buy 3 new routers when we meet capacity of our two machines.

    Lasers work great for cutting thin materiel but after about 3/8" thick in our case, The router was the way to go. If you dont have a commercial router, check to see if anyone in your area does. Ive have found so many small to medium sized wood shops in my area more than happy to share knowledge and show me there production shops. You will run into some Aholes for sure but there are many business owners out there willing to help.

    With the right setup you should be able to get a nice cut in acrylic with little clean up.
    3X Camfive 1200 48" x 24" 100watt Tube
    Zcorp 450 3d Printer
    Laguna Smartshop 2 - 4x8 ATC

  11. #11
    HI Robert,
    thanks for the reply. Our router used to be an Esab, with 16 ft rails and a gantry that allows the spindle to span 2 metres width.
    Born in 1988-89 in USA.
    It was gutted and retrofitted with Aussie Tekcel electronics 17 years ago, and a motorised Z axis added. I removed the acme thread and delrin nut and put a ballnut screw on it, and modified the servos a bit. (long story, for another day).
    3HP Perske spindle, running from via a VFD from a 3kw rotary phase converter supply, off 240VAC single phase.
    No vacuum.

    'In our area' there is no one- just me, for a 70km radius in all directions. At 75km away are two signwriters also with routers, with standard 2400 x 1200 beds, and smaller lasers than ours.

    Photo below of a job on the router at the moment- 4.7 metres long ironbark (Aussie very hardwood) slab, left over after we had the tree milled.
    This was 700 wide by 130 deep and 6 metres long, but for the job at hand I pruned it back to 525mm wide and 90 deep and 4.7m long.
    It weighs about 1/4 ton as is... no fun to have to move or to roll over! ( I faced the back of the slab first, then tipped it this way up)

    I've routed some of the design in it...

    P.S. I had to resharpen the cutter three times... and had similar issues years ago when freehand routing in big old ironbark logs.
    You get a bit of resin on the cutting edge, and it starts to overheat and get blunt and then burn, and then stall...
    It takes less time to just touch up the edge a bit as you go.

    This pic has a tape measure buried in sawdust at the front, and the slab was 4" thick at that stage...


    26166265_10215295013866180_2867501861069372165_n.jpg
    Last edited by Ian Stewart-Koster; 12-30-2017 at 5:26 AM. Reason: typo
    Best wishes,
    Ian



    ULS M-300, 55w made 2002 with rotary. Goldenlaser 130 watt, 1300x700 made 2011.
    Flat bed 2500x1300 150/90watt 2 tube laser, 2018 model.
    Esab router, 1989, 4.5 x 2.0 m, conv. to Tekcel, and modded a 2nd time.
    HP L260-60". Roland PNC-1410. Mimaki GC-130 SU.
    Screenprinting carousel 6x4 and 7x4 ft 1-arm bandit vac table.
    Corel Draw X3, Illy, Indesign & Photoshop CS2 & CS5, Enroute 4
    Pencil, paper, paintbrush, airbrush & dagger-liners & assorted other stuff.

  12. #12
    Join Date
    Nov 2012
    Location
    Brisbane, Australia
    Posts
    284
    Hi Ian,

    I have just realised that you may be interested in my JKlaser(GSI) DC tubes that I have replaced with Yongli DLT-300. Originally each tube is 140W but one of them is dead and another outputs about 127W. Each comes with a power supply. I also have a beam combiner that has been used with them.

    Dave has recommended me a company in UK which can repair and refill these tubes and their quote is quite reasonable. I think it was 2700 BP for regassing both tubes together and 200 BP for a repair. I did not go with repair because I needed my big laser working asap and I did not want to run into risk of breaking the tubes in transit which would also cause me going with replacement and waiting much longer. I have an original shipping box for these tubes but the box is for one tube only.

    I want to get rid of these tubes so if you are interested PM me. Originally they were sold for about $6000 USD each brand new and I am not sure that price included a power supply. But anyway I am not going to ask anything close to that price considering they need re gassing and repair. These two tubes combined will cut 20mm acrylic easily with excellent beam profile and thin kerf.
    GCC Spirit GX Pro 100W(synrad)
    Laserlife Ezlaser LCW 300W(Yongli DLT-300)

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