September 27, 2016 at 5:27 pm #18556
Yea the pwm definitely works. I use m106 s5 to focus my laser. S127 is also much weaker then 255 as expected.September 27, 2016 at 5:28 pm #18557
You’re not running repetier firmware though right?September 27, 2016 at 5:29 pm #18558
No the vicious firmware without graphic LCD modified for laser as per your tutorial.September 27, 2016 at 5:34 pm #18560September 27, 2016 at 5:39 pm #18564
maybe need to play with contrast etc more.September 27, 2016 at 5:52 pm #18566
could my amperage on my driver be too high?September 27, 2016 at 6:02 pm #18568
My Sd card is tied up in my 3d printer right now so I tried running your file from pronterface instead. Got the same result as you….charcoal. I aborted the job after a couple of minutes.The movement is much slower and not as smooth as printing from SD directly. I recently upgraded my Marlin too so I may have settings to adjust.
Attachments:September 27, 2016 at 6:04 pm #18569
must be something with img2gcode or the image itself maybe… and that sucks cuz I love that image.September 28, 2016 at 5:34 am #18601
PicLaser also did the same thing. Jeff is telling me 1300 mm/min is way to slow for a 3 watt diode. Suggests 2540 mm/min and possibly a lower max value.September 28, 2016 at 7:13 am #18605
After looking around and doing some reading… Wonder if its the wood I am using. It is just standard contruction grade spruce plywood. Everyone else seems to be using solid wood (pine, oak, cherry etc) or even mdf. Is something like pine or oak plywood ok?
I think a trip to the lumber store tonight might be in order.September 28, 2016 at 8:53 am #18616
I use between 20-30 mm/s and the laser is usually at 50-80% max power. I might lose some resolution that way but things come out great. Test everything with a small 20mmx20mm picture and when the settings are goo move on to something larger. Every piece of wood will be different, even flipping it over can need a settings change.September 28, 2016 at 9:02 am #18617
I think I must be over powering it big time… Interested to see what @leo69 comes up with today.
I think I might try again at 30mm/s at 50%.September 28, 2016 at 5:56 pm #18668
Well bought some good side 1/4″ plywood. Having much better success tonight. This engraving was only 20mm x 35mm.
Attachments:September 28, 2016 at 6:30 pm #18679
I tried burning one of the files you posted yesterday. It’s the dragon at 3000 feed rate and 30 percent power I think. Still way too dark and can barely recognize the image. Tried same file on white cardboard and it barely touched it. The darkness of the material you use will have a huge affect on the power and speed needed. The dragon image you posted is especially tough. The entire image is really dark with almost no contrasting details. I’ll try again tomorrow. It’ll be a challenge for sure. I was running firmware with 11 bit gray-scale resolution for a while. Might need to dust that off for an image like this one.
Attachments:September 28, 2016 at 6:34 pm #18681
Of course that would be my luck. I pick the most impossible picture to try and learn with. My larger jets logo is looking much better then the small one in posted earlier. I sped it up and lower the power a little further for the second one.September 28, 2016 at 6:45 pm #18683
Well at least your gear is working. Just trial and error remains.September 28, 2016 at 6:46 pm #18684September 29, 2016 at 4:36 am #18695
After some more tweaking and playing with the jpg itself…
Attachments:September 29, 2016 at 6:15 am #18711
@leo69 you mentioned a version of the firmware with 11/12 bit resolution… would you be willing to share? I think that might be handy or is it for more powerful lasers?September 29, 2016 at 1:16 pm #18732
@jason The higher PWM resolution is better suited for higher powered lasers that burn at lowe percentages of full power on some materials. Still, I can see where it would help with an image like your dragon. Any image that doesn’t have too many shades of gray to begin with AND has to be run at less than full power may benefit from higher PWM because it will allow you to burn at less power while still keeping all 256 shades of grayscale resolution. One thing I noticed last night is whether I set federate at 1000mm/min or 3000mm/min, my machine appears to move at the same speed. I think the acceleration settings need to be bumped up to allow increased speeds due the tiny incremental moves that are being made when engraving. I used to laser etch much more than I have lately so I’ve forgotten most of the observations and adjustments that I’ve made in the past. The test burns I did last night were with default settings on newly flashed RC Marlin so I didn’t take time to tweak my acceleration settings for raster engraving.
The modified PWM Marlin firmware that I was running a few months ago was a much older version that didn’t have some of the cool additions featured in the current Marlin RC version. I’ll try to apply the same patches to the current version and I’ll definitely share with you if successful. One thing I DON’T want to do is put myself in a position where I have to support something like that so you’ll need to accept under those conditions:) I’ll keep you posted.September 29, 2016 at 1:17 pm #18733
Looking much better now:) I see some actual shades now and the detail is good.September 29, 2016 at 2:33 pm #18740
My best results have been at about 40% of max power. Running at 2500 or 3000 mm/min (cannot recall at this moment). Not quite as many shades of grey as I was hoping for so was hoping your firmware would help that… Maybe need to bump up the speed more yet.September 29, 2016 at 2:51 pm #18743
If bumping up speed doesn’t appear to have an effect then bump up acceleration settings too. Do a search for M201 and M204 codes to see the syntax. These can be put in your image2gcode pre-processor text to set laser acceleration at the start of the gcode file without having to flash firmware.September 29, 2016 at 2:59 pm #18744
Is it in the firmware that the speed is limited? I changed it to 4000 mm/min and it doesnt seem any faster then 2500. I guess if the accel is too low it cannot speed up sufficientlySeptember 29, 2016 at 3:15 pm #18745
Exactly, Each pixel in the image is a .18mm move at default resolution settings and the gcode does one pixel at a time so max speed will never ever be reached. Acceleration will have a big impact on this , maybe even jerk settings but those are a mystery to me. The accel settings can be changed with the Mcodes I mentioned right within the program so that makes them easy to experiment with . Also, you know the changes won’t be permanent, reverting back to firmware defaults when you cycle power. you don’t want high accel settings to stick when cutting and should stick to Vicious recommended settings in your firmware.September 29, 2016 at 3:37 pm #18750
Jerk as I understand it used in changing directions. And since we are travelling in straight lines acceleration should be the sole limiting factor.November 18, 2016 at 5:54 am #21131
Well after a couple of months away doing mirrors I am back to trying to figure out images in wood… I have been fighting with it for the last couple days with marginal success. Text and lines dark stuff comes out decent but shading is not working very well. I think I need the speed to up much higher. In image2gcode i have been using 4000mm/min but it does not appear to be much faster then 1200mm/min. I have set the acceleration to 1500 in the header script as well as changing it on the control menu on the screen… I have not tried writing it my SD card and see if it is just the computer that cannot keep up.
Is anyone else getting good results burning images with the MPCNC? Please share your settings.November 18, 2016 at 9:15 am #21141
The accelerations slow the speed. each transition between light and dark usually triggers an accel/decel.
I burned images at about 20-30mm/s. Using about half power on the laser in pine.
I’ll look I am pretty sure I posted my setting on the forums somewhere. I got it to almost burn an imagine in a piece of cardboard. It worked except the 100% black burned through. So I no you might lose some resolution but just turn down the laser.November 18, 2016 at 9:45 am #21143
I think it might have been the picture I was using… I switched the picture to one with less glare on the persons face and it looks like it is turning out much better. I did this one with the same settings 4000mm/min 50% power. Hard to tell over a web cam lol.
What do you have you accel set to? Just the default 400?November 18, 2016 at 9:57 am #21145
I can’t put up a picture of the one I did My friend would get pissed I found a picture of her picking her nose and burned in on the IPE, HAHA.
I really used the laser for 2 days straight then I only break it out to kinda burn my logo on things So I haven’t actually used it in that way in a while.
But yeah I just flash the firmware with the pin swap and go, I didn’t change anything else.
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