Chinese Lasers-Rodney Gold And George M. Perzel please help!!!!

[Brian Martin Pennsylvania]

Good Day,
I’m in the market for a flatbed laser, preferably Chinese since that’s what I can afford right now. I came across three Chinese companies, Redsail, Iehk, and Shenhui. Redsail and Iehk carry the 48” x 96” flatbed laser but Shenhui does not. This is what I want to accomplish. I’m cutting 18”x 5/8” strips out of a 4’ x 8’ piece of High Impact Polystyrene. My goal is to place the sheet on the laser bed, press a button and let the laser do its thing. I have a lot of questions about Chinese lasers so if anyone has one please put your two cents in.
Here are some of my questions.------Rodney Gold and George M. Perzel please help me out!!!!!!!!!!

1. What is autofocus.
2. Are U.S. parts interchangeable with Chinese. (Lens, Mirrors, Tubes)
3. Would there be a problem running these lasers continuously during an 8 hour day. I read some comments on here about upgrading the chiller unit from Redsail.
4. For the people that own Chinese laser cutters, what are the lead/delivery times from China.
5. Are the wattages the same here as in China. For instance my material cuts flawlessly on a U.S. 150w laser. Should I expect the same from a Chinese laser.
6. If anyone has any upgrades they made themselves on the machine please feel free to talk about them.

[Talley Boatwright]

I can answer a few of your questions. I have done many imports in the past. Personally, I would not consider Redsail at all.
I run three type of lasers, CamTech L20, Epilog Legend 36EXT 60 watt, and G. Weike LG3040 40/50 watt.
Two RF sealed C02...Synrad...Coherent and one glass tube. The sealed tubes are more reliable than glass tube. However, more expensive. Power is not the same, even though rated same power. Glass tubes have be sealed properly in order for the gas not to leak. Importing also can be tricky if no research is done. I did my own importing and it tales about 35 days roughly. That is considering customs and railroad. Feel free to ask me any questions if need.

[Brian Martin Pennsylvania]

Thank you Talley. What's your recommendation for a Chinese flatbed laser that can handle 48" x 96" material. Are sealed C02 laser tubes universal and are there any modifications I can make to be confident that I can get 150watts out of the laser to cut my material. BTW I am very handy with tools (welding, pneumatics and fabrication) so heavily modifying is not a problem.

[Rodne Gold]

Good Day,
I’m in the market for a flatbed laser, preferably Chinese since that’s what I can afford right now. I came across three Chinese companies, Redsail, Iehk, and Shenhui. Redsail and Iehk carry the 48” x 96” flatbed laser but Shenhui does not. This is what I want to accomplish. I’m cutting 18”x 5/8” strips out of a 4’ x 8’ piece of High Impact Polystyrene. My goal is to place the sheet on the laser bed, press a button and let the laser do its thing. I have a lot of questions about Chinese lasers so if anyone has one please put your two cents in.
Here are some of my questions.------Rodney Gold and George M. Perzel please help me out!!!!!!!!!!

1. What is autofocus

1. Are U.S. parts interchangeable with Chinese. (Lens, Mirrors, Tubes)
2. Would there be a problem running these lasers continuously during an 8 hour day. I read some comments on here about upgrading the chiller unit from Redsail.
3. For the people that own Chinese laser cutters, what are the lead/delivery times from China.
4. Are the wattages the same here as in China. For instance my material cuts flawlessly on a U.S. 150w laser. Should I expect the same from a Chinese laser.
5. If anyone has any upgrades they made themselves on the machine please feel free to talk about them.

Autofocus is a means where the laser focuses itself , often both inacurate and troublesome .. don't bother with it.

Any lens and mirror can be used with the machines , US or not. Sealed RF and glass Tubes as well , however replacing your glass tube with a sealed CO2 RF will be PRICEY
Motors and stepper drivers etc can be interchanged , but motherboards probably not. Price of spares for a chinese machine is real cheap , adding a raft of them to your laser if you bring one in will not cost a lot

I run mine 8 hrs a day , 5/7 and have had 2 years use (almost) ..just replaced one of my 60w glass tubes at a cost of $170 , got at least a years use out of it..it didnt fail completely but was down on power.


Lead times depend on whether yours is a custom build or something unusual or one of their stock units . Have a look at the sticky at the top , look at the despatches from china link and you can see the scale of the chinese factory I went to..confidence inspiring (Shenui)
I would allow 2 months from order/deposit to your door , 3-4 weeks for the custom build..3-5 weeks for shipping and clearing. Putting pressure on the mnfgrs to deliver sooner will get you a shoddy product. I understand the angst of paying a producer a zillion miles away and waiting for em to ship etc..

No , you wont get the same cut from a 150w chinese laser in terms of speed and perhaps cut width or quality , the beam shape is not as good and neither are the lenses you get supplied , you would have to cut slower HOWEVER at 1/5th of the cost , you can afford to buy 2 and exceed production of 1x 150w mainstream machine. Quality will be very acceptable , its not like it wont cut at all or be real bad.

I wouldn't suggest upgrading anything as a DIY unless there is an issue..buy one and run it

If your machine is expensive EX china , like $15-25k , why not fly over and go visit ..interesting place and the cost will soon be overwhelmed by your piece of mind , might save you from making an expensive mistake. Take your material with and ask em to run tests , most co's will oblige..face to face is big in china , if you do go , they will respect you and realise they can't dicker with you.

I was real impressed with Shenhui , even if they don't carry a machine that size (I'm not too sure any of the others will have it in stock for immediate shipping...most tend to build to order) , I saw plenty flatbeds there, *they* build to order , workmanship on my machines is very good.

[George M. Perzel]

Brian;
Rodne pretty much answered your questions. I would be leery of trying to cut a 4x8 sheet on any laser much less a chinese one as focus over that area will be very difficult to maintain. Also your machinje will be huge a weigh a ton-can't you cut your sheets into 32 x48 size and use a smaller machine? I am close to you up here in NY-call if you want to discuss anything.
Best Regards,
George
Laserarts
585-924-4519

[Sam Larter]

Brian,

I've been looking for a Chinese laser for a while and have read through the last two years of posts here and there is another Chinese Laser manufacturer that makes a machine large enough for your purpose.

They are G. Weike and they have received many positive reviews by people here.

They have a laser cutter with a bed size of 1300mm x 2500mm listed here: http://www.wklaser.com/product/11_194.html that can be ordered with up to a 200W laser tube. Check them out and see it they can help. From what I've read on here and other websites is that the two best Chinese manufacturers are Shenhui and G. Weike. Most of the U.S. sold and supported machines are made by these two companies.

Good luck,

Sam

[Talley Boatwright]

Thank you Talley. What's your recommendation for a Chinese flatbed laser that can handle 48" x 96" material. Are sealed C02 laser tubes universal and are there any modifications I can make to be confident that I can get 150watts out of the laser to cut my material. BTW I am very handy with tools (welding, pneumatics and fabrication) so heavily modifying is not a problem.

With my experience Jinan G. Weike is a good company to deal with. Sealed C02 laser tubes are universal; however, the tubes cost more than buying a complete machine depending on the wattage. Plus you have to purchase the power supply, control module etc.

As far as Auto focus goes, I totally disagree with Rodne about inaccurate and troublesome. Auto-focus can be tweaked for optimal focusing. If you are running the same flat and level material...yes, it is best to manual focus because auto-focus does slow up production by 20 seconds each time at the most.

May I ask, what type of work are you planning to do with 150 watts of power? Kern Laser offer flatbed lasers with plenty of power but costly.

[Brian Martin Pennsylvania]

Photo0423.jpgTalley,
I will be running the same flat and level surface, even the material won't change at all. The only type of work that will be done with the laser would be cutting 18" x 5/8" x 3/16" strips made out of high impact polystyrene. (HIPS) I actually contacted Kern Lasers and sent them a sample of my HIPS and their laser cuts the material beautifully on a 150w laser so I was guestimating that a 150w lasers would be the optimal choice. Their lasers however are a little bit out of my price range. 100,000.00+... But their customer service is amazing.

[Brian Martin Pennsylvania]

"No , you wont get the same cut from a 150w chinese laser in terms of speed and perhaps cut width or quality , the beam shape is not as good and neither are the lenses you get supplied , you would have to cut slower HOWEVER at 1/5th of the cost , you can afford to buy 2 and exceed production of 1x 150w mainstream machine. Quality will be very acceptable , its not like it wont cut at all or be real bad"

Thanks Rodne for your input and advice. Speed right now isn't a big concern compared to quality. Would I get a better cut if I bought American lenses and perhaps a sealed U.S. tube. The picture I included is my material cut on an U.S. Kern 150w laser. I'm hoping to get a similar cut on a Chinese laser. The material is 3/16" high impact polystyrene.
Photo0425.jpg

[Talley Boatwright]

Did Kern give you some settings that your material was cut at? 150 watts is a lot for a laser. I guess I need to do some research on this material. What application is it used for?

"No , you wont get the same cut from a 150w chinese laser in terms of speed and perhaps cut width or quality , the beam shape is not as good and neither are the lenses you get supplied , you would have to cut slower HOWEVER at 1/5th of the cost , you can afford to buy 2 and exceed production of 1x 150w mainstream machine. Quality will be very acceptable , its not like it wont cut at all or be real bad"

Thanks Rodne for your input and advice. Speed right now isn't a big concern compared to quality. Would I get a better cut if I bought American lenses and perhaps a sealed U.S. tube. The picture I included is my material cut on an U.S. Kern 150w laser. I'm hoping to get a similar cut on a Chinese laser. The material is 3/16" high impact polystyrene.
Photo0425.jpg

[Rich Harman]

I have compared pieces cut by a 75W Epilog, 120W Universal, and my 80W Shenhui.

Don't know about the kerf width but I cannot tell any difference in quality of cut.

[Brian Martin Pennsylvania]

Thank you George for your input. Can you explain to me what you mean that the focus would be hard to maintain over that area, I'm new to lasers so I'm dealing with the learning curve. I can cut the sheets down but I would then loose material. I can get about 341 pieces out of a 4' x 8' sheet but if i cut those pieces down I would loose material. (I'm planning to mass produce these 18" x 5/8" x 3/16" strips of High Impact Polystyrene)

[Brian Martin Pennsylvania]

Yes the settings that Kern gave was 1" per second at 100% power at 150w. The HIPS material is being used for the body of a magnetic pickup tool. Its a thermoforming plastic if that helps.

[Rich Harman]

Three ways I can think of that it will "lose focus".

1) 48 x 96 is a very large area to keep absolutely flat. Even with a perfectly flat table the material can bow or warp so you may need a way to hold it down - such as a vacuum table.

2) All laser beams diverge. That means that if the beam is the diameter of a pencil when it leaves the laser tube it may be the diameter of a hot dog by the time it gets to the furthest point on the table. For example my 35" x 55" laser has a beam path that is about 120", at its furthest point the diameter is about 10mm. To compensate I cut things a little slower in the far corner of the table. This problem can be minimized by using a beam expander but then you lose depth of field. However, a machine as large as you are contemplating will probably have the laser tube mounted to the gantry so the length of the beam path may be short enough (probably less than 80") so that this effect may not be an issue.

3) The longer the beam path, the more sensitive the alignment. The tiniest bit of misalignment will result in a great loss of power when the cutting point is furthest from the laser source. The same amount of misalignment would be completely undectable on a machine with a shorter beam path.

A machine such as mine (most larger Chinese machines I think) has pass through capability. You could get a smaller machine and setup a feed system to move the material through the machine. The software has provisions for this but you would need to construct your own feed system.

I am sure that there are people here that would be willing to make some test cuts for you on their machines. Probably a good idea since you know exactly what you need to use the machine for.

[Rodne Gold]

Yes, if you changed to a Sealed RF synrad or the like tube and used quality lenses , you would get the same cut, HOWEVER it is a snap to do so , most of the chinese motherboards have provision for PWM control , and replacing a lens is , well replacing a lens.
What I would do is try a machine with a glass tube etc first, IF it doesn't work , then go RF tube (you would have to change the laser power supply and tube)
Before going RF tube tho , I would just change to quality lenses. I might have to do a retraction to the folk here ..cos I was convinced via trying, that the cheaper chinese lenses were as good as the more expensive optics , well we changed out a cheap lens in one of my machines for a slightly battered expensive one from my mainstream lasers and it does cut quite a lot better....
George is saying that maintaining complete flatness on huge bed sizes is VERY difficult. At the very least , you would have to have a proper floor/bed for the machine as any small twist that results from an uneven floor (even if you level the machine) can translate to a coupla mm on the bed. Added to that , even transport can twist the bed outa shape. I don't think the laser mnfgrs in China are able to construct a huge machine with such precision..BUT its not a major issue , you could construct a sub bed and clock that up.....