My New MPCNC

This topic contains 78 replies, has 5 voices, and was last updated by  Jeffeb3 2 weeks, 5 days ago.

Viewing 30 posts - 31 through 60 (of 79 total)
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  • #44073

    Jeffeb3
    Participant

    Douglas,

    The laser gets power from the driver, which has its own power supply. That’s where the current comes from. The logic for when to turn it on and off and at what power is what you use the Arduino/Marlin for. That’s why you don’t use D8-D10. At least that’s how I’ve seen it done, and that’s what’s in the guide.

    1 user thanked author for this post.
    #44075

    Ryan
    Keymaster

    Dang it is so much more clear when you explain it. I should have payed more attention in English classes.

    #44076

    Douglas Bell
    Participant

    Hi Ryan

    sorry the document you supplied had me a little confused as the main reason for remapping the pin is that the laser used has a 5v TTL and D9 outputs 12v.

    From what I have read on the endurance laser specs is the driver they are using requires a 12v TTL so remapping would cut the power in half for the laser.

    It’s late and I may be misreading things, so I will give all the documents a good read in the morning, and apologise if late night reading is confusing me 🙂

    #44077

    Douglas Bell
    Participant

    Damn didn’t notice the last 2 replies before posting, sorry Jeffeb3, wasn’t ignoring your post, here is the document for my laser page 27 see if it clears anything up.

    http://endurancelasers.com/download/Guidance%20how%20to%20connect%20laser%20to%203D%20printers%20and%20CNC%20machines.pdf

     

    #44082

    Jeffeb3
    Participant

    With a 12V TTL , you can wire it up like in that manual (cool that it covers MPCNC).

    As for where the laser gets it’s current, I’d have to see the schematic for the driver. But if it’s really just a 12V TTL, and it is also connected to a power supply, then the amount of current coming from D9 should be minimal, so you wouldn’t need more current to drive it.

    Ryan, I failed all my English classes. Sometimes it just takes someone to say it differently.

    #44142

    Douglas Bell
    Participant

    Hey guys.

    I failed English and I am British, lol

    Spent all day trying to get my damn laser working.

    First issues was my fault, designed and printed a mount for my laser for the MPCNC then realised had no way to focus the laser when mounted. oh my design choices the joy.

    Hooking up the laser and getting it to work not an issue, using DFX2GCODE works great for basics and cutting no issues there.

    Engraving on the other hand using Image2Gcode, just cant get it working, tried lots of different settings from laser power to feed rates and most of my tests just end up black with the faintest hint of the drawing, stuck a volt meter on the D9 terminals and the voltages are varying depending on the image, tested laser by varying the output using the M106 S and the strength of the laser varies depending on the number from 0 – 255 I put in.

    So I just cant figure this out, I have attached the image been trying to burn.

    iu

    I have also attached my Gcode for the image, maybe its a setting issue I have not done or is not correct.

    Attachments:
    1. leapord.nc
    #44216

    Ryan
    Keymaster

    Try starting with some basic vector graphics. Solid lines. That way you can verify it turns on and off and how much power you actually need at what speed. Going straight into etching isn’t easy.

    #44220

    Douglas Bell
    Participant

    Hi Ryan

    It works fine with basic Vector images / outline images. and it works great with just black and white images, it just seems to be etching or PWM control, just in case even tried connecting it like the instructions you gave me but that just resulted in the same just with half the power.

    Need to do some more testing with the driver itself, I know the terminals on the Ramps are varying the voltages for PWM, just wondering if the laser driver is, could be a wiring issue on my laser module as I have never tried engraving side with it just the cutting or basic vector drawings.

    One thing I have noticed and it just might be me being stupid with no real knowledge of electronics but if I stick my meter on the + and – on the D9 terminal on Ramps and adjust the fan speed it adjusts the voltages being read.

    If I put my meter between D9 + and the Ramps common ground the voltage never varies it reads 12v all the time even when I adjust the fan settings, is this normal?

     

    #44227

    Jeffeb3
    Participant

    Where are you reading “common ground”? Can you take a pic of the wiring? Especially the green power connector. Maybe you need to tie the grounds together on the green plug?

    #44233

    Douglas Bell
    Participant

    Hi Jeffeb3

    Sorry not at home at the moment so can’t get pic.

    I have the power supply plugged into the 5A ports on the Green Connecter, nothing in the 12A side, I assumed common ground would be the negative on the 5A side, again not great with electronics but learning everyday so apologies if I am wrong.

    #44234

    Jeffeb3
    Participant

    Ah, I think you want to jumper across the positive and ground from the 5A side to the 12A side. D9 gets powered by the 12A side.

    1 user thanked author for this post.
    #44235

    Douglas Bell
    Participant

    Ah

    ok, will give that a shot tomorrow evening and get back to you.

    thanks Jeffeb3

    #44271

    Douglas Bell
    Participant

    Hi Jeffeb3

    Bridging the 5A and the 12A made no difference, still have the issue of the laser not varying with the graduation of the greyscale in the picture.

    I did try changing the Fan pin from 9 to 44 again as per Leo’s instructions but that made no difference apart from barely running the laser.

    #44277

    Ryan
    Keymaster

    If you send it the manual commands show in the instructions does the power vary then? As in is this a hardware or software issue.

    #44361

    Douglas Bell
    Participant

    Hi Ryan

    OK some more testing on my laser today.

    I can confirm:

    M106 S0 – Laser Off
    M106 S255 – Laser On
    M106 S125 – Laser Half Power

    I tested variations in between those numbers and it visibly effects laser strength, but I also used a piece of card and managed to go from no impact, to light burn, heavy burn to burn through the card, so the M Codes are defiantly effecting the laser strength manually, just cant understand why its not when trying to engrave a picture, the LCD shows the fan value changing to the different strengths as its etching the picture but just doesn’t seem to be having an effect on the laser. I am stumped!!

     

     

    #44382

    Ryan
    Keymaster

    Dang it I have replied 3 times….

    Condensed version.

    Ty putting the “f” commands at the end of a G0 or G1 line. The gcode looks funky but that is the only 100% wrong thing I see.

    I only use my laser for vector stuff lately, maybe I will try it tonight and see if your code works. If I take a break from the current project I’ll give it a shot.

    #44387

    Jeffeb3
    Participant

    Did you post the gcode somewhere?

    You should also make sure there aren’t any S256’s or S254.5 or something. I wouldn’t trust Marlin to parse it right.

    Did you try with a simpler image? Something like a black circle in a gray box or something? Might help you narrow it down. I could even be 1/2″x1/2″ (try your favorite flag, that would be neat seeing it that small, but I digress).

    #44443

    Douglas Bell
    Participant

    Hi Jeffeb3

    the gcode is posted in the post with the pic of the leapord,  it’s called leapord.nc

    #44462

    Ryan
    Keymaster

    There was just a post in the laser thread. The new firmware is choking of the parenthesis and that “F” command need to follow an “G” command.

    Try the following.

     

    Attachments:
    1. leapord-2.nc
    #44503

    Douglas Bell
    Participant

    Hi Ryan

    Thanks for the reply, unfortunately that made no difference at all, I had already been manually putting the Feed Rate in besides the G commands as per a post of yours in someone’s laser post.

    I contacted the manufacturer of my laser and they seem to think that the D9 terminal on my ramps board, the voltage control is on the negative and not the positive, I thought it may be an issue with the ramps board so I put a new one on, same thing. The laser works great for cutting, just doesn’t seem to work with greyscale engraving.

    I have been given a small circuit to create to try to put between the Ramps and the laser but have no PNP Transistors so waiting for them to come tomorrow. Will see if this makes a difference.

    My Dremel bits should be here tomorrow aswell so will get a play with them.

    #44528

    Ryan
    Keymaster

    That doesn’t make sense to me, if you can manually lower the power, I would assume that means it works?

    #44547

    Douglas Bell
    Participant

    Hi Ryan

    it doesn’t make sense to me either, but it could be that my testing is at fault and the laser is only turning on and off at certain values, at the end of the day it’s the cutting that is more important but would be nice to do grayscale engraving.

    #44563

    Ryan
    Keymaster

    Tell me what happens with this one.

    Attachments:
    1. lasertest.gcode
    #44567

    Douglas Bell
    Participant

    Thanks Ryan

    will give this a test tomorrow, managed to track down schematics for the laser driver, mines is the Mk3 not sure if these will tell you anything or not.

    http://www.robots-everywhere.com/re_wiki/pub/web/Main.LCheapoSchems.html

    #44601

    Douglas Bell
    Participant

    Hi Ryan

    I tested your Gcode, I get 3 black lines then the lines begin to degrade (no change in greyscale, but broken lines)  until not visible.

    #44606

    Ryan
    Keymaster

    You might want to show that to the laser manufacturer I think something else is wrong. That code is as simple as it gets and slow so it should work. I would guess your driver is funky. Or maybe they can reply with a test code that they feel should work?

    #44616

    Douglas Bell
    Participant

    I also tested the circuit that the manufacturer wanted me to try, that didn’t work either, so my next question to them is my driver faulty, waiting on a reply.

    #44617

    Jeffeb3
    Participant
    I contacted the manufacturer of my laser and they seem to think that the D9 terminal on my ramps board, the voltage control is on the negative and not the positive

    That might actually make sense. Because D9 is designed to run a large load, the signal might not be switching fast enough with a high impedance load (basically no load).

    Or, it could be that the differential between D9+ and D9- is switching between 0-12V, but the +terminal is always 12V, but the D9- is switching between floating and gnd. If they are really looking for the difference between D9+ and some other ground, then the floating ground pin wouldn’t turn off the laser.

    #44618

    Ryan
    Keymaster

    This might be why Leo switched pins, and why the voltage divider didn’t work. I know there was an issue and it might have been speed related. I can’t remeber the conversation. I will check and see if I still have it in my PM’s.

    #44619

    Douglas Bell
    Participant

    Hi Jeffeb3

    Yeah that’s exactly what they said and that’s why they gave me a circuit to build, although I have no idea how its meant to work, but I did build the circuit but it didn’t work.

    I have attached the circuit if you want to have a look, you will be better placed as to see what it is doing.

    LaserCircuit

    Attachments:
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