[kb0nly]

I recently acquired one of these 40w lasers from China, after hearing all the horror stories on here I wasn't expecting much but figured it was a good place to start learning lasers and with the recent price drops they are under $400 now so why not take a chance on a project.

What arrived really surprised me! Initial thoughts was that it came well packed, double boxed, adequate packing, nothing missing.

Mine came with Corellaser and Laserdrw, so far software wise it's been pretty uneventful, already had Coreldraw installed so installed Corellaser and plugged in the key dongle and that worked fine. It's USB and plugging it in I got a notification that said laser machine connected.

Before plugging it in however I did the usual of opening everything up and checking over the wiring, I was shocked to see how nice it was! Everyone seems to find crazy problems and quality control issues in these but mine was nice and clean and tidy. Heatshrink on connections, all the wiring to the control panel was loomed and anchored with cable ties, proper crimps on terminals, good soldering, I couldn't find anything wrong. The panel with the switches and meter is a removable steel panel with a thick vinyl label over it, sturdy and good finish, doors fit well and everything seems pretty sound electrically and mechanically.

Came with the same crappy blue exhaust hose as others and the exhaust fan is pretty cheap but works, I already replaced the exhaust system so no worries there.

After getting water running through it and the air bubbles pushed out I checked mirror alignment and it was really quite good! The second mirror needed a slight tweak as it was a bit high but that didn't take long to fix. I am replacing the head with the air assist one from light object and that's all going well. A quick mirror adjustment and it should be good.

But back to the beginning, after getting the software installed and water running I did a couple test engraves and they looked great, cut some 3mm acrylic and no problems there, set it to 10mA and 5mm/s and it produced a nice looking cut without any fuss.

Either they have really stepped up their game or I was lucky and got a good one, but so far I'm really impressed.

Once I'm done with all the upgrades and modifications I will post some more pictures but for now I gotta say for the money to have a working laser cutter that was running fine in less than an hour from receiving it is a win in my book!

[kb0nly]

I got a few more pics of my progress.

The exhaust system has been redone now, removed the exhaust piece inside, nozzle or vent or whatever you want to call it, and cut it back for more room. Installed a new adapter i made on the back, was 3d printed from a design i found on thingiverse and works really good. I bought a inline duct fan off eBay and a speed controller for it and got that all hooked up with 4" hose, the draw is fantastic, no smell or smoke escapes to the room when cutting. So far very pleased with it.



I also quickly drew up a mount for an air fitting for the air assist head i got from LightObject, you can see it in that picture just to the left of the exhaust vent. There was already an unused hole in the panel there so i just made a panel mount which holds a fitting for 1/4" tubing on the outside and a barbed fitting on the inside for 1/4" flexible air line. I also made up a couple cable chains to feed the air line and the 5v to the small pointer laser i added as well. It's not hugely accurate but it at least gives me a close idea of the head location above the material. I also removed the spring loaded clamp from the stock bed and cut down the height of the standoffs holding the bed plate to allow the right focal distance for the new head along with a piece of honeycomb material that i also got from LightObject.



The cooling system right now is just a 5gal bucket and the stock water pump that came with it, i plan on making some changes there as time and money allows. I have a 240mm radiator that i kept from an old water cooled gaming PC that i scrapped out last year, got it for free after it was damaged along with everything else in their house by a lightning strike. So i plan on putting a radiator inline with the cooling system and beefing up the water flow with a better pump as well as adding a safety to it with a water flow switch, etc.

It cuts 3mm plex with ease and i tried some 1/4" plywood tonight and that was equally as easy. Engraving has been fun, i've designed a few custom things and tried it out, worked great each time.

As far as the software coming with these now, the only minor complaint that i have is when your using the CorelLaser plugin for CorelDraw that the plugins toolbar disappears after starting an operation, and the only way to get it back is to close and re-open the program. Maybe i'm missing something, is it a setting perhaps?? I haven't been able to figure that one out. However using LaserDRW for engraving it works just fine, i can pause and resume, start and stop, etc. But with the CorelLaser plugin that little toolbar disappears and the only way to stop the laser is flip the power switch. That reminds me another mod i'm going to do is add an emergency stop switch to it as well, thats coming soon.

I was able to import pretty much anything i have been working on into CorelDraw, dwg, dxf, svg, wmf, pretty much anything anyone sends me or i have designed over the years. Including all the common and a few not so common image formats.

I was thinking about a DSP controller upgrade but as of yet i don't see a reason for it, the operation has been smooth, steppers are quiet and its accurate and not missing steps. Pretty much all the horrors i have read about with the Moshi units are nonexistent on these current machines. No weird problems between the computer and the controller board, USB connection to it has been rock solid and never has an issue. Running this on Windows 10 Pro and it knew right away what it was and pops up little notifications when CorelLaser is sending data to the controller, shows a percentage of data sent then says 100% sent to controller then pops up progress notifications and when its done it pops up that the operation is complete and how long it took to do, etc. Overall i couldn't be happier with how well its running.

So far so good!

[Phil8920]

Nice job on the printed add-ons. Would you be interested in printing and selling another set? I bought that same system yesterday from eBay and have already purchased the air-assist, honeycomb, lens and mirror upgrades from Lightobject. I love how clean your setup looks and would like for mine to look the same. Hopefully the system I'm getting will be as good as yours is and I won't have any issues.

[kb0nly]

The carriage and x-end parts would be really cheap to make and ship, the exhaust adapter is pretty big though, that took a fair amount of material and time to make. There is a laser cut design for a similar adapter on Thingiverse that would be easier to make without access to a 3d printer.

I forgot to mention, the cable chains are the 10mm size ones from LightObject, the original design for these parts was for a 7mm cable chain but the only 7mm ones i could find were on eBay from China and would have taken weeks to get here. I can't take full credit for the 3d printed parts, i found them on Thingiverse but then had to modify them to fit this newer model as they were hitting the back wall before the home switch, i guess the K40 and DC40 before it had the switch farther forward or the back wall was in a different position. So i ended up using them as a base for a redesign to fit mine.

The air inlet i made as well, its just a quick connect fitting for 1/4" tubing on the outside and a 1/4" barb on the inside screwed together with that little orange panel inbetween and attached over the existing open hole that was on the back of the cabinet.

-

[kb0nly]

I got some questions about my exhaust fan so here it is...

Attachment 305554

Nothing fancy, its a Ventech 200CFM inline blower fan, you can find this type all over eBay and Amazon, sold as "Grow Room" exhaust fans... LOL

Mine also came with the speed controller, just one of those controllers like you would use for a router or drill motor with a three position switch, on, off, controlled by the speed knob. Its really a quiet fan, i'm quite surprised with it actually. I run it full speed when cutting and generally around 50% when just doing some engraving. Its so quiet in fact that i mounted it to the wall now next to the laser in the same room with me, just sounds like a furnace running on the other side of the room, actually i think its even quieter then that, more like just a decent fan running in the summer time, its pretty unobtrusive and you can talk normally right next to it. Comes with a good mount but it does cause just a little vibration, i think i will make some rubber isolators for it but unless you put your hand on the wall its mounted to the vibration isn't much of an issue either. Pretty pleased with it, got a deal on this one from eBay for $60 including the speed control.

Working on the water flow protection now... Here's some advice, don't buy the cheap water flow switch from LightObject.com... I figured it would do the job and it only had one bad review so i gave it a shot, but its got issues. It will turn on when water is moving through it but shut off the pump and it can take an hour or more before you hear it click off. Not sure why, i think its a diaphragm based switch and the residual pressure in the line keeps it switched on until the pressure drops? If anyone could suggest how to make this switch operate better that would be helpful, I have one of the magnetic flow switches on order to swap it out but would like this one working until that arrives (slow mail from china), they are not pressure dependent but true flow switches, no movement no switchey switchey...

Heres the flow switch i bought, it was only $7.50 so i figured since i already had an order coming from them why not give it a shot, but i'm pretty unimpressed with it.



I also got a step closer on finishing up the water cooling, right now its still just a five gallon bucket but i have test fit most of the parts and will be getting the little 240mm radiator inline with a couple fans on it to add a bit more cooling, though most of the time even with a fairly long cutting operation i don't see much of a spike in the temp, maybe +5-8 degrees after a 10-15 minute cut cycle. So i think the radiator and fans will help reduce the temp spike, but being as its winter time here even being in a heated room the reservoir bucket sitting at the floor level in my basement shop is kept pretty cold. Water temp in the bucket is around 62-65 degrees, but that will change when summer comes.

Actually i have been thinking about summer time as well, if i put the radiator inline it could be positioned near the air conditioner vent to pump some extra cold air through the radiator. I have a 10k BTU portable AC unit that i run for cooling and dehumidifying in the summer time. The 3d printers can bring the room temp up quite a bit, even though they are enclosed with their own vent fans the radiated heat from them can be felt a foot away on a cold day.

[ls009]

I really like the air 3D printed parts you've added, would you share the files / links at all?
I'm keen to add the extra smaller laser to end to help line things up.

Can you provide a bit more info on the smaller laser and how you modded the bed? is that the "honeycomb" part from LightObject?
Sorry, I'm very new and just bought the same model K40 as you have, I got mine really cheap locally and have just started playing with it

[mondo50m]

Where did you get the STL for the above air and laser holder? I have searched both Thingiverse and Youmagine with no results similar to yours. Is there a link that you can give us? Or, perhaps, the STL file itself for those of us who have a 3D printer?

Milt

[kb0nly]

K3020 Laser Air Assist by kb0nly - Thingiverse

Not sure why the search wasn't bringing it up for you, it was the second result for me when i search for Laser Air Assist.

[kb0nly]

I really like the air 3D printed parts you've added, would you share the files / links at all?
I'm keen to add the extra smaller laser to end to help line things up.

Can you provide a bit more info on the smaller laser and how you modded the bed? is that the "honeycomb" part from LightObject?
Sorry, I'm very new and just bought the same model K40 as you have, I got mine really cheap locally and have just started playing with it

Sorry for the delay in responding! We had a blizzard this week and between that and work i haven't had any time!

Check up one post, i linked to the files on Thingiverse.

The Honeycomb is the one from LightObject. As for modifications all i did was remove that spring loaded clamp thing from the stock bed because it wasn't flush with the top of the plate, i left the stock bed plate minus the spring loaded clamp assembly, which removes with just four screws, and then just put the honeycomb on top of that. However, i also replaced my laser head with the air assist one from LightObject, which moves the lens up slightly and changes the focal distance so i didn't have to modify the standoffs for the factory bed plate that much, if your using the stock head you might have to put it down even further. But all i did was do a ramp test with a piece of birch plywood on an angle on the stock bed plate, theres plenty of explanation of a ramp test on here and it was easy, then once i found the focal distance of the new air assist head i measured from the tip to the spot on the ramp test and then put the honeycomb in and measure from the tip of the head to the top of the honeycomb and found i was about 3mm to high. To fix this i removed the rest of the screws that hold the stock bed plate in, its sitting on long threaded standoffs, then i took the standoffs and removed about 5mm from each one, this allowed me to drop the 3mm i needed and put a 2mm thick washer on the top of each standoff, giving me some play for adjustments. Put it all back together did some test cuts on the honeycomb and everything seems great!

I have been thinking about getting an adjustable Z axis but for now thats just on my wish list, i mostly cut 3mm birch and acrylic so i set it's height for optimum cutting of those materials.

The smaller laser i got off eBay..

1x Red Laser Diode Module 12mm Focusable Lens Cross 5mW 5V CNC USA | eBay

There is cheaper ones on there but this one was a US seller and shipped from the US and good quality.

[kb0nly]

Made some progress on reworking the control panel today, got everything reinstalled in the new panel except for the emergency stop switch and temp display which are not here yet.



I engraved and cut 3mm birch, sanded, stained and sealed it then cut a piece of 3mm acrylic to overlay it as well. Turned out pretty nice!

[kb0nly]

Got the stop switch today! It was good and bad...

Ok first the good, its installed in the new control panel and working. The bad... Ugh, the switches didn't work out of the package. I bought two brand new switches, yes made in China but sold by a US seller on eBay, shipped from California. They are the type with one side is a NC switch and one side is a NO switch, so i bought two so i could swap the blocks around and make a DPDT NC stop switch, but what i found was neither of the NC switches had continuity through them in either position!! So i took them apart and found the terminals inside where cruddy, looked like some dried up grease or gunk on them, wiggling them i could randomly get continuity or high resistance but nothing better. So i completely took them apart, pulled the contacts out, toothbrush and alcohol and then even a soft plastic bristle wheel in my rotary tool at low speed to buff them further, reassembled with new contact grease and they worked. So i went through all that trouble rebuilding two brand new switch modules and afterwards i put the leftover NO switch blocks on the other switch body to save for another project and found they had the same problem, gunked up crud in them!! These were brand new, so i can only suspect the cruddy grease they used in them dried out while sitting on a shelf somewhere.

Anyway.... After all that was done, which most would think it a pain but i found it quite fun to take apart and see how the switches work and check their contacts for quality etc, here it is installed and working!

[kb0nly]

Water temp is finally done! To install the thermistor into the water flow i got a nylon tee fitting and a cap and two right angle barbs. I drilled a hole in the cap and put the thermistor through and a bit of hot glue just to hold it temporarily while i poured some two part epoxy into the inside of the cap to pot the thermistor in place with just the tip out past the end of the cap. That way it threads into the side of the Tee and the water flow goes past it, seems pretty accurate so far.

Attachment 308094

The barbed fitting is screwed in from the back holding the tee fitting to the back panel on the inside, no other mounting needed. Then i got the new water flow sensor plumbed up, this needed a way to mount up so i just quickly 3d printed a couple saddles to clamp it and attach to the back of the machine, the reason for it being located where it is on the back corner is the radiator still has to be plumbed inline after it.

Attachment 308096

And finally the display is mounted in the new control panel. There is a few more mods to come to the panel, there will be LED's, a flashing red indicator and a green indicator that will show if the water is flowing, the flow switch will be part of a custom circuit i am building that will trigger a relay to enable or disable the laser as well as switch on a green led for good and a flashing red indicator led for no water flow, as well as a small piezo alarm to alert me to a water flow problem.

Attachment 308098

More on the monitoring and alarm system as i get working on it, waiting on some bits to arrive in the mail to finish building that. I designed and milled a PCB for this circuit, so it should go together pretty quick once the rest of the bits are here!

[abyss]

Where exactly did you get the K3020 itself and what was shipping cost?

[TroyO]

I would be interested in the vendor info too.

[RustyBrooks]

I would be interested in the vendor info too.

Me too

[kb0nly]

Go to eBay, search for item number 281580482963

Thats who i got it from, he has raised his price slightly but still a pretty good deal! Sorry for the delay in posting back, its been pretty busy here lately!!

[kb0nly]

I finally got the water flow alarm finished, the red and green led's above the temp display. Green of course means good, if water flow stops the red led flashes and a piezo alarm also sounds, along with the laser getting disabled.



I also finished the cooling system finally, added a 240mm radiator with two 120mm fans installed. My average water temp is between 67-71F, the room its in is fairly cool this time of year, but in the summer its right next to the air conditioner vent so it shouldn't increase much!

[Ranscon]

Looks like you have done some great mods. I also have the spotting laser. Did you wire it to the laser's electrical and if so, where did you tie it in? or did you use a separate power source? Also, I am adding air assist but have been trying to find out how much air is optimal? I have several large compressors but they are way too loud. I want to switch to a commercial aquarium pump. When searching, I have found posts that recommend everywhere from 9lph to 3200lph. That is just too big a difference for me to figure out what is needed. I want to have enough without overkill. I know 5-6 psi is plenty but cannot convert that to lph or gph which is how aqua pumps are measured. Trying to keep the budget to a minimum so don't want to buy a $150 pump if the $35 one will be sufficient.
Thank you for any info you give me on this, Jeff

[j1432]

I just bought one of these 40 Watt units as well. My results haven't been as rosy as the rest of you. I've been experiencing some fluctuation in the laser power and general strangeness. Yesterday I cut some thick paper with no problems. Today I tried a different design and the laser was having trouble cutting the paper unless I took multiple passes... If I fiddle with the current control knob I can sometimes get it to cut properly if I find the 'sweet' spot where the power supply seems to get a bit quieter and sounds more like white noise than a whine. Is my power supply supposed to be making any noise at all other than fan noise? When pushing the test button it seems like it would cut better for just a moment before dropping significantly in power.

[Louis_Cannell]

I cut card and thick paper with 2.5w diode if laser struggling to do this then abeam alignment, tube or HV suply is and issue, I have one of these new sitting in a box as a free gift came in for inspection after tube laste 2 hours, company couldn't even be bothered to collect it. Full refund was given on eBay after claim made and item was due for collection but as they ccould not be bothered to collect wanting me to post its now a free gift to me, these tubes lose catalyst sitting around on ships for months then in warehouses and getting a good one really depends on getting a fresh one as much as anything. Struggling to cut paper would be an indication of problems as 2.5w diode will cut paper all day long.