5W+ Laser

This topic contains 29 replies, has 6 voices, and was last updated by  Leo69 1 year, 3 months ago.

Viewing 30 posts - 1 through 30 (of 30 total)
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  • #14285

    Jakob A
    Participant

    Tested my new laser from optlasers.com this weekend.

    First test: Will it cut 6mm birch plywood ?

    Yes it will, first attempt failed with 6 passes at 300mm/min, 2nd try 8 passes at 300 mm/min success (left a round mark on the spoil board too )
    With better focus adjustment 1mm per pass might be possible.

    #14290

    nerdyrcdriver
    Participant

    Sweet!

    #14422

    KRavEN
    Participant

    Can you provide any additional information like which laser you’re using and how you have it mounted? Any pictures of your setup? I had read that for thicker plywood you might need blower assist to remove the ash/char after the laser passes. Did you need this or have you tried it?

    Thanks for sharing!

    #14467

    Jakob A
    Participant

    The laser is this one (Based on a NUBM44 diode) : http://optlasers.com/en/home/78-clh-5000-engraving-laser-head.html
    Since I’m using a Kress spindle the 43mm laser head fits in the same mount.
    I don’t have any more pictures yet, the wires and driver is tied on with zip ties at the moment 😀

    I did not use blower assist for that test, the seller claims that its able to cut 10mm plywood so I figured 6mm should be easy 🙂
    After checking I realized that I was actually using the 3 element lens and not the included single element lens (some kind of aspherical lens, not G2), the results might be even better with that one.

    #14470

    KRavEN
    Participant

    That’s pretty simple then. 12v power in and with the analog 0-5v modulation I think there should be no problem using any PWM pin on the arduino to control the output power.

    Now I just need to figure out how to plop down the $340 without the wife having a go at me.

    #14474

    Jakob A
    Participant

    I bought it with the 7.5V psu included and used pin 44 like in the 100$ 2.8watt laser guide, has no problems with it 🙂

    Just give her 340$ for clothes and it will be fine 😀

    #14480

    Leo69
    Participant

    Nice laser, I’ve had my eye on one of these for a while myself. The cost should be under $200 total. The assembled diode with 3element lens is $106 at dtr laser shop. I wouldn’t buy a cheap Chinese driver but go with one from x-wossee on eBay.He has a good rep in the laser community and sells a5amp driver for about $40. That driver should be able to run from your ramps power supply a long as it meets the current requirements.

    #14483

    Leo69
    Participant

    Don’t forget to add a decent heatsink and laser goggles for another 50$ or so but that still ends up under $200 id you don’t need to buy a new power supply.

    #14484

    KRavEN
    Participant

    Well that I could do and I was an electrical engineer in a past life so can probably do a little more research and work out the details. Do you have any forums threads or websites you would suggest I start at?

    #14489

    KRavEN
    Participant

    Is this driver okay or does it need the driver you linked?

    Found this “So you want to build a laser” thread

    #14491

    Leo69
    Participant

    I just glanced at it but it didn’t appear to support pwm for grayscale engraving. If you only plan to cut with it then it’s fine but I’d definitely get the x-wossee driver instead if you want to do grayscale. It (x-wossee) also has lots of extra features like interlock inputs for safety enclosures and thermistor input to allow overheat cut off. I think you can tune it with a voltmeter without having to construct a test load as well.looks like a great driver.

    #14493

    KRavEN
    Participant

    Yes, it does have PWM. He has docs there explaining it. The site you had screenshots from is considerably cheaper than his ebay or amazon stores. I got the full 12mm module with 3 element glass lens and 4500mA driver for $160 shipped.

    Now for eagle pair safety glasses $47.68 shipped and probably this heatsink $7.36 that I’ll mount a fan to that I already have.

    Grand total: $215.04

    #14503

    Leo69
    Participant

    I’m not so sure about pwm support on that driver. It can be driven by ttl logic , on or off, but i don’t think this will do pwm. Can you ask seller to confirm? The dtr laser shop site describes the buck drivers like the one you bought and refers you to other sellers if you need a driver with modulated input. This kinda convinces me that theirs doesn’t support it. Let us know when you find out.

    #14521

    KRavEN
    Participant

    For some reason the eBay listing has the most info. Basically remove the 10k SMT resistor between the enable pin and vcc. Then connect the AVR pin to the enable pin with a 10k resistor. Enable pin is on at 1.8v and off at 0.6v so that’s why the 10k from the AVR 5v PWM is needed. I will confirm with the seller.

    #14543

    Leo69
    Participant

    On at 1.8 and off at .6 implies it responds only at those thresholds for on and off switching so i don’t think grayscale will be possible. I hope I’m wrong….

    #14572

    SteveC
    Participant

    For the Laseerer X-drive DTR’s page mentions TTL/PWM modulation frequency of up to 5kHz:
    https://sites.google.com/site/dtrlpf/home/flexdrives/x-drive. So make the mods including removing the ramp up capacitor and it looks like it PWM control should work.

    I’m going to try this so KRavEN it would be really great if you could post any results here.

    Thanks,
    Steve

    #14577

    Leo69
    Participant

    5khz frequency is the speed that it can switch at based on the input signal and it will accept ttl or pwm signal but my concern is the threshold voltages that are mentioned for switching off and on. That doesn’t imply that the output will modulate in correlation to the input signal does it? I contacted the seller myself but no answer yet. I still think the x-wossee driver is better suited for this type of thing. Those little buck drivers are tailored for handheld ray guns that the laser enthusiasts like to build:)

    #14581

    SteveC
    Participant

    To be sure yes it would be best to hear from the seller but those thresholds are just TTL min high and max low specs just like you would expect for any PWM input. So if the laser can be turned on and off at that frequency then the average beam power will be proportional to the pulse ratio. Think about it like this – take a PWM TTL signal and low pass filter it. The output will be an analog signal proportional to the PWM ratio. The laser is just heating the material. The material will have a relatively long (relative to the 5KHz) thermal time constant. This will act like the low pass filter. Does this sound right?

    The one thing that bothers me about the X-Drive is that the current is fixed 4.5A. I would prefer to be able to tweak it downward.

    Steve

    #14587

    Leo69
    Participant

    Must got a reply. Looks like it’ll work but the seller recommends other drivers.see attachment

    #14590

    Leo69
    Participant

    To me, ttl is different from pulse width modulation so i get thrown off when the seller recommends other drivers for modulation. TTL just means digital high and low switching doesn’t it? Oh well, if anyone gets one to do grayscale then keep is posted on the results.

    #14593

    SteveC
    Participant

    Leo69,
    Thanks for posting the reply. So by “full featured” I think he means having an easy way to set and read the max current. Unfortunately they are from Russia and Germany and will take a bit to ship to the US. It would be nice to also find a switching regulator.

    Yes TTL just means the logic level. A PWM signal generically is a digital signal that must have a logic level specified and is used to control a driver transistor. Again as I mentioned above, the X-Drive application info is using that TTL input to turn on and off the laser driver at a 5KHz rate with a particular on ratio. This will vary the average output power and give us gray scale burning. The slew-rate capacitor will need to be removed for this to work.

    Steve

    #14608

    KRavEN
    Participant

    Yes, PWM is just switching on and off really fast. Seller recommends 1khz switching frequency. The output power is fixed but can be adjusted via a different resistor or add a trimpot. If you wanted to get fancy you could also use and I2C trimpot and a little code work in marlin to set the output power with g-code.

    #14618

    SteveC
    Participant

    KRavEN,
    For the SDX V3 Super XDrive where is the resistor that adjusts the current? I don’t see it in the DTR’s Laser Shop page. Where did the seller DTR specify a 1kHz PWM frequency? In a personal message? DTR’s page https://sites.google.com/site/dtrlpf/home/flexdrives/x-drive specifies 5KHz.

    Would be nice if they supplied schematics for these things. It’s not nice dealing with a black box.

    Thanks,
    Steve

    #14650

    Leo69
    Participant

    Marlin firmware uses the analogWrite function to drive the fan output , which uses 8-bit PWM at 490Hz frequency. Firmware mods are possible that can increase the frequency and/or the resolution by reconfiguring one of the 16 bit timers and writing to the OCR register directly instead of through the analogWrite function. The increase in PWM frequency doesn’t really make a difference with laser engraving from what I’ve seen but the increase in PWM resolution does help with high powered lasers.

    #14657

    KRavEN
    Participant

    KRavEN,
    For the SDX V3 Super XDrive where is the resistor that adjusts the current? I don’t see it in the DTR’s Laser Shop page. Where did the seller DTR specify a 1kHz PWM frequency? In a personal message? DTR’s page https://sites.google.com/site/dtrlpf/home/flexdrives/x-drive specifies 5KHz.

    Would be nice if they supplied schematics for these things. It’s not nice dealing with a black box.

    Thanks,
    Steve

    I did an inquiry on eBay and that was in his response. I know that the output is set via resistor because some of the driver pics show a trimmer but he said in an Amazon review or question that they don’t have them anymore and are set via resistor now. He also sells the same driver in output from 2amp up to 4.5amp in .5amp increments. Once I get mine in I’ll trace it out and build a schematic for it. These things aren’t super complicated so I don’t think it will be difficult.

    #14658

    KRavEN
    Participant

    Marlin firmware uses the analogWrite function to drive the fan output , which uses 8-bit PWM at 490Hz frequency. Firmware mods are possible that can increase the frequency and/or the resolution by reconfiguring one of the 16 bit timers and writing to the OCR register directly instead of through the analogWrite function. The increase in PWM frequency doesn’t really make a difference with laser engraving from what I’ve seen but the increase in PWM resolution does help with high powered lasers.

    I’m using a MKS SBASE board with SmoothieWare firmware for my MPCNC. I think it’s a better fit because it has support for CNC, laser, and 3d printing and DRV8825 stepper drivers. It also has PWM available on a bunch of different pins that support PWM frequencies well above 5Khz.

    #14660

    Leo69
    Participant

    Wow. Just spent a half hour reading about the MKS SBASE. It looks awesome! This will definitely be my next upgrade. Thanks for posting

    #14663

    Ryan
    Keymaster

    Crazy timing. I just asked one of my vendors for some of some of those sbase boards. But I was trying to get the one with the larger drivers though. Gotta love the digipots and I won’t have to sit here assembling the ramps sets!

    #14705

    KRavEN
    Participant

    If you want to start a new thread for it I can provide my config file for MPCNC. I’m just about done with my build now. Finished assembly and got X and Y moving last night.

    MY todo list:

    1. print and attach the end stops
    2. drag chains
    3. laser mount and router mount
    4. remote speed control for the DWP611
    5. design and print enclosure for the MKS SBASE
    6. raspberry pi, octoprint, camera
    #14707

    Leo69
    Participant

    I was reading that smoothieware currently has no support for laser engraving, only laser cutting, but it will be implemented in the future. I wonder if we can implement through the fan control in the meantime, like we do with marlin? I’ll have to download this firmware and start studying it. A dedicated smoothieware thread might be a good idea. I think interest in the 32 bit platform will definitely pick up.

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