40W Chinese laser questions. How to make it cut?

[Steven Soong]

Hi all, first post here. I bought this 40W laser to cut and engrave wood 2 years ago. I only paid $299USD at the time so I knew what I was getting into. After I received the laser and did the setup, it engraved wood and paper nicely. My setup is using water and a block of ice to cool the water down to 12C idle and around 25C when engraving.

I used it a few hours a week for engraving and it did okay. The questions, I noticed the resolution of the laser is not as high compared to some wooden boxes we purchased from China (Ie. fonts that were 2mm in height is not as sharp). Is this because of the cheap focusing lens or incorrect distance from the head to the work piece?

Secondly, when I tried to cut a piece of wood "887654 Birch Plywood 3mm 1/8 x 12 x 12 (6)" it won't go through even after 10 passes. I also have ran the laser at 100% while attempting to cut. I've seen other K40 do 3mm cut so I am not sure what is wrong here. Again, have anyone make it cut 3mm wood with the stock china parts?

Lastly, the laser just died while I was trying to test engrave on a piece of paper. You can see the design super faint as if it is working at 1% power. I performed suggested tests and concluded that either the tube or the psu is dead. I ordered a similar 40w tube/psu combo from www.automationtechnologiesinc.com (http://www.automationtechnologiesinc.com). I hope this will fair better. I know now it is bad to run the laser at max. Does anyone know if the stock ammeter is a reliable indicator of the working current or is that garbage as well? I will monitor the new tube to ensure it doesn't go over 15ma.

Lastly, If anyone has any information on how I can improve this laser to cut my 3mm plywood that would be great. Is that stuff from automation tech actually an upgrade or is it just as bad as the stock parts? I got a new fume exhaust and am thinking about upgrading the mirrors and air assist head and also a water chiller soon.

[Scott Marquez]

Steven,
Welcome to Sawmillcreek.
It sounds like you may have multiple problems, either do a Google search of past posts of this forum or go through it a page at a time( I went over two years back when I was new) you will soon start to see a trend of problems on these machines and ideas to isolate and fix them.
Scott

[Bill George]

Sounds like you got yourself one of those infamous K40 laser machines off eBay and now you want to make it work? You might have 1 or 2 people on here doing those as a hobby, your better off doing a google and finding a forum where those hobby users hang out. One thing you will find out for sure is that to make those K40's work its going to take a lot of time and money. Cheap mirrors, lens, power supplies and tubes will all need upgrading. Not to mention the controller.

[Gary Hair]

Sounds like you got yourself one of those infamous K40 laser machines off eBay and now you want to make it work? You might have 1 or 2 people on here doing those as a hobby, your better off doing a google and finding a forum where those hobby users hang out. One thing you will find out for sure is that to make those K40's work its going to take a lot of time and money. Cheap mirrors, lens, power supplies and tubes will all need upgrading. Not to mention the controller.

But they use a high quality power cord... Keep it and just upgrade the rest!

[Bill George]

Ok, now I see Automation Tech is now offering support on the K40 machine for $50 per hour and I assuming you need to pay in advance? I think LightObject.com is doing about the same now. I guess its a lot more cost effective here.

http://www.automationtechnologiesinc.com/products-page/laser-engraving/co2-laser-machine-software-training

[Matt McCoy]

Hey Steven, I'll echo what Scott said and add this:

1) Switch out the new power supply and tube, when you get them, and see if you can adjust the output on the PS to prevent overdriving the tube. Google some help along the way and be careful.

2) Clean/Align the mirrors/lens and measure your focus.

3) You should be able to cut true 1/8 BB pretty easily with good results in 1-2 passes.

Hope that helps.

[Steven Soong]

I saw that $50/hr support too, i can already see them using the 5 mins to tell you to upgrade everything. Case closed.

I do want to get the laser to cut my 3mm wood if it means upgrading the lens and mirrors. On a side note, what setup do I use for the air assist? I see someone use a air compressor with air regulator to bring down the psi but its kinda loud.

Steven


Ok, now I see Automation Tech is now offering support on the K40 machine for $50 per hour and I assuming you need to pay in advance? I think LightObject.com is doing about the same now. I guess its a lot more cost effective here.

http://www.automationtechnologiesinc.com/products-page/laser-engraving/co2-laser-machine-software-training

[Bill George]

I saw that $50/hr support too, i can already see them using the 5 mins to tell you to upgrade everything. Case closed.

I do want to get the laser to cut my 3mm wood if it means upgrading the lens and mirrors. On a side note, what setup do I use for the air assist? I see someone use a air compressor with air regulator to bring down the psi but its kinda loud.

Steven
Head over to Lightobject.com he has complete upgrade kits and a new head that takes air assist. No, he does not charge for free advice like Automation Tech, they even have a Forum where you can read up and post questions.
But when the reality of the cost of all the upgrades and your time kicks in, you might just want to cut your losses and get a machine that works out of the box.

[Steven Soong]

I would definitely do 1) and see if i could restore the engraving first. I do like the upgrades offered by LightObject and AutomationTech. I would like a 24x16" laser but it takes up so much space!

From what I know, the controller board controls both the cutting head and the power of the laser separately. Theoretically, one can upgrade a crappy k40 to do a 60w laser, tube extension and upgrade PSU for added cutting ability right?




Hey Steven, I'll echo what Scott said and add this:

1) Switch out the new power supply and tube, when you get them, and see if you can adjust the output on the PS to prevent overdriving the tube. Google some help along the way and be careful.

2) Clean/Align the mirrors/lens and measure your focus.

3) You should be able to cut true 1/8 BB pretty easily with good results in 1-2 passes.

Hope that helps.

[Kev Williams]

Upgrade it? Why not just replace the thing? To have a $300 anything last 2 years is amazing these days. It cost a whole $12.50 a month, which if nothing else provided you with some very cheap training. Not sure I'd want to throw any more money at it...

The best way to turn a Kia into a Bentley is to just buy a Bentley... ;)

[Bill George]

So figure $400 for real 40 w tube & PS, DSP upgrade another $500, air assist head and decent mirrors w/ Lens another $150 or so. It adds up.

[Steven Soong]

I finally got the 40w tube and PSU from automation tech and got my machine to engrave again! Now I still want to to cut my 3mm plywood. What is the suggested water temperature when cutting? I had my ice water at 13C idle and then 14-17C engraving. Should I get a air assist nozzle or can I just zap strap an air hose to the head? Also, what about getting a water chiller, would keeping the temp under a certain level at all times prolong the life of the laser tube?

[Bert Kemp]

Laser tubes run best and last longer if run at below 70f I run mine at 64 to 68 . Cutting with a 40 watt laser is slow even with 3 mm but can be done with slow speed high power and yes air assist will help. The biggest thing in cutting is proper focus. With out that cutting will be very difficult. If you are cutting all day long then a chiller migh be your best bet, DON"T get a 3000 get the 5000. If your just cutting a few hours here and there Ice jugs in the water bucket work well. I have a 5 gal bucket I put 1 gal frozen milk jug in and it keeps my water around 65 to 69 for hours when it starts to get warmer I put in a new jug. I have a digital thermo gun I check water temp with as I work.

[Steven Soong]

@bert, thanks, I ordered a chiller CW3000, air nozzle, and a better fume extractor. I think it's better to be on the lower end of the temp when cutting, around 13C rather than over 20C.
For the air assist, I will just hook up the shop compressor and regulate it to 50psi.

As for the cutting area. it is currently only 300mmx200mm (12x8in), has anyone to to upgrade this to say 20x12in?

[Bert Kemp]

Steven the 3000 is not what you want and if you can change it I would suggest you do. The 3000 is not a chiller its just circulates room temp water , if your room is 70 your water will be 70 if your room is 89 your water will be 80.You really want the 5000 as I mentioned in my last post.


@bert, thanks, I ordered a chiller CW3000, air nozzle, and a better fume extractor. I think it's better to be on the lower end of the temp when cutting, around 13C rather than over 20C.
For the air assist, I will just hook up the shop compressor and regulate it to 50psi.

As for the cutting area. it is currently only 300mmx200mm (12x8in), has anyone to to upgrade this to say 20x12in?

[Dave Sheldrake]

The only upgrade for the lens is to move to genuine II-VI lens's,@ $100 or so
Mirrors are K2, you could upgrade to Si but there is no real benefit
12 degrees is too cold, start at 16 and try to keep it stable, stable wins every time 16 to 22 is good
Your next problem will be when everything is running fine you will find it doesn't cut square, then it is likely to be the entire stage needs replacing with an LO version.
The mainboards on the K40 and K40 clones are twitchy, plan on one of those dying in the first year of use.
The K40 as standard is too narrow to hold a 40 watt tube, the tube is a 32 watt average, 35-38 watt peak, 15mA will kill it, try 12mA

I have to echo what Gary rightly said, the only part worth keeping in 99% of K40's is the power lead :(

[Steven Soong]

That is very interesting, I will keep those numbers in mind when i get to it!


The only upgrade for the lens is to move to genuine II-VI lens's,@ $100 or so
Mirrors are K2, you could upgrade to Si but there is no real benefit
12 degrees is too cold, start at 16 and try to keep it stable, stable wins every time 16 to 22 is good
Your next problem will be when everything is running fine you will find it doesn't cut square, then it is likely to be the entire stage needs replacing with an LO version.
The mainboards on the K40 and K40 clones are twitchy, plan on one of those dying in the first year of use.
The K40 as standard is too narrow to hold a 40 watt tube, the tube is a 32 watt average, 35-38 watt peak, 15mA will kill it, try 12mA

I have to echo what Gary rightly said, the only part worth keeping in 99% of K40's is the power lead :(

[Steven Soong]

OMG you are right. So this could even be worse than my ice water. But do I have to sell it or will it do it's job for cutting with the 32w laser.


Steven the 3000 is not what you want and if you can change it I would suggest you do. The 3000 is not a chiller its just circulates room temp water , if your room is 70 your water will be 70 if your room is 89 your water will be 80.You really want the 5000 as I mentioned in my last post.

[Bill George]

No Bert gave you good advise and that was it. What you have is nothing more than a glorified radiator like you you find on a car or truck. The rest of the advise given you was for your benefit, the K40 machines are for someone who like to tinker, not for money making. Un-fortunately you are like I am with some projects, it was fun to build and learn but its really worth nothing at resale time.

[Steven Soong]

I just cheaped out and got the $220usd CW-3000 instead of the CW-5000. But not all is lost, I saw in another thread that you can use a $100 5000btu window air conditioning to pipe air into the input and it will cool it down pass ambient. http://rvroadtrip.us/library/van_airconditioner.php




No Bert gave you good advise and that was it. What you have is nothing more than a glorified radiator like you you find on a car or truck. The rest of the advise given you was for your benefit, the K40 machines are for someone who like to tinker, not for money making. Un-fortunately you are like I am with some projects, it was fun to build and learn but its really worth nothing at resale time.