Hi. I’m new to laser cutting. I purcheassed a K40 50W 40x40 cm.
My first test was cutting a 10x10mm square and it turns out as a 10.23 x 10.37 mm rectangle. Is there any solution to this? What should I investigate to solve this? I’ll be doing further tests with a bigger square, like 5 x 5 cm for better accuracy, but anyway, I would like to get the best accuracy also on these small dimensions.
Thanks
Welcome to the forum.
What software are you using to control your K40?
Hello. Thank you. I’m using CorelLaser
Using Corel means you have the Nano2/3 controller board. Pretty much everyone uses MeerK40t for software for that instead of Corel, but regardless what you need to do is the same for Corel or Meerk40t, which is to find the config file and change the value for “steps/MM”. You will want to do the math of figuring the percentage correction needed and applying that to the original value(likely to be around 157) in the config file. Then retest and tweak if needed. Hopefully someone will know the file name to look for but again…config should be it. I stopped using Corel the first few days and did not look back.
Yes I have the M3 Nano. I read that the Meerk40t supports up to M2 but not M3, that’s why I didn’t try with it.
I found a file in C:\Program Files (x86)\3WCAD\CorelLASER called EngraverSetting.ini with the following content:
[DeviceOptions]
LogicOrgX=187.013
LogicOrgY=161.039
EngraveToFile=0
Rotate=0
Mirror=0
Style=1
Grave=1
CuttingNearest=0
CuttingOrder=0
Speed=320
CutSpeed=10
OutLine=0
CuttingJoinGap=0
LocateFrame=1
LocateMode=0
HandLocate=1
CompilerMode=1
Steps=4
CuttingSteps=1
EngraveCount=1
LaserPower=75
OutBoundsLine=1
Increment=0
Unidirectional=0
SwapAxis=0
RotaryWork=0
PluginsSetting=11801105
[HardSetting]
MainboardRegcode=***********
MainboardModel=5
OrgPosition=0
VertLaserHead=0
CornerSpeedRatio=0
SystemDPI=1000
MaxWorkSpeed=500
PageOrginX=1
PageOrginY=1
PageSizeX=400
PageSizeY=400
TaskPriority=3
AntiDisturb=0
BacklashAmend=0
XRailLength=200
YRailLength=200
But the only options that allow me to change the axis config individually are
LogicOrgX=187.013
LogicOrgY=161.039
PageOrginX=1
PageOrginY=1
PageSizeX=400
PageSizeY=400
XRailLength=200
YRailLength=200
Should I change one of those?
Thank you
Where did you read that? Here’s status from almost exactly a year ago here:
Where did you read that?
IN the official github page:
Ah, as far as I can tell the M2 Nano support happened always to also work for the M3 Nano and it was being considered just another revision of the type for that supported device list.
@Tatarize / @Protopia Want to change the Meerk40t README to mention M3-Nano as well? 
Sorry, but due to an ethical and cultural disagreement with the owner of MeerK40t, I am no longer contributing either code or Wiki enhancements, though I remain an enthusiastic user of MeerK40t and continue to give feedback on bugs, usability etc.
Well, as you said, the Meerk40t supports the nano M3. I’m using it but there’s an issue when I try tu cut a square. Colored it red for cutting, and the laser is making a dotted line with low power. I think the power in this machine can only be controlled from the hardware, but anyway, I set it at 30 in the Software.
This is the result:
@mcdanlj Another issue was that even setting the config for a 40x40cm bed, sometimes, while moving the head with the software controllers it doesn’t figure the bed’s limit and makes an horrible noise like crashing against the limits. I’m afraid of breaking something.
Nevermind. I realized it was the “power” I set on 30, it really was the ppi that it’s in 1000 by default. I don’t know yet how that power control based on ppi works but it seems when you put it at 30 instead of 1000 it results in dotted lines
Watching a David Olsen tutorial on youtube I saw he has this same issue with the horrible noise. It sounds exactly the same in my machine.
https://youtu.be/sHMY-FEYfsY?feature=shared&t=283
Any solution to this?
Maybe I should open a new tread with this problem.
Thanks
At above 100 PPI the dots should overlap. But, really PWM sort of works the same thing, it’s a duty cycle with time-on and time-off. You can also set a dot-length as a special thing, if you somehow wanted a dotted line you wouldn’t need a loupe to see.
That sound is if you forget to home the device and turn it off or something. It’s the steppers sending the device into the wall. It’s somewhat harmless but can cause issues with your belts etc. and should be avoided if you can.
But I don’t know how to avoid it. I’m using Meerk40t now, sometimes when I ask the header to go to the drawing position it keeps going on that direction till it crashes with the wall. Sometimes I click on the Home button and it seems it forget to stop when it arrives the 0,0 position. I downloaded the K40 Wishperer but it’s the same. from time to time the movement commands are bugged .
You could add in a pre-home if it’s happening a bunch. Basically it can happen if the program is turned off when the laser moved or is shutdown between different movements.
The controller doesn’t know where it is, so that’s tracked by the program. But, if things turned off or the laser head was moved, the info is wrong and the device needs to be rehomed such that 0=0 and is knowable.
