I was just on ebay and see they have Chinese laser drivers at 5amps for $20. These would easily drive the 3.5watt nichia ndb7a75 diodes at the dtr shop. Who’s gonna try it first?
Your killing me!!! Stronger laser?!?!
I was looking at it this morning. Biggest advantage would be faster etching and/or thicker material cutting? Would it be significantly better for 2 times the cost?
A laser kit would be Awesome. I bet you could design a sweet looking mount too.
No i don’t think it would be a big improvement. We can already etch wood, plastic, leather. Only the commercial 50watt plus diode lasers can etch bare metals .The only advantage would be the speed increase.
A couple of people asked so I’ve just put the laser mount I made for my MPCNC up on thingiverse in case anyone wants to use it. It’s kinda corny with the magnets and stuff but it does work well and it’s very secure and quick to install and remove.
Hi Leo This is excellent work! I already build a laser engraver, but I’m looking to ‘migrate’ the laser to the mostly printed CNC (once ready), thx for the write up.
I actually have a 2.8 watt laser so it will probably go just fine!
@Karel. Thanks. My laser also came off of a dedicated engraver that I built a year ago. The mpcnc has great precision and a huge work area so you’ll be very happy with your decision to move your laser.
Glad to see you got it going Tony. The picture is a little grainy, that mount is cardboard?!
It was just a quick and dirty test directly on the spoilboard. It didn’t turn out too good.
I used I2G (MPCNC ver) at 500mm/min and 1000mm/min and at both feed rates the x-axis will go about 15mm, slow down (very briefly), go another 15mm and repeat for the whole length, in both directions. It did this when burning from the SD card and when connected to the PC and controlled by Pronterface. I havent tried any other gcode sender, any recommendations?
I’m wondering if maybe I have my Marlin feedrates, acceleration and jerk settings messed up or if something else is going on. I don’t notice the jerkiness when using the router. Are you using the default movement settings in your configuration.h file?
I got the G2 lens with my NDB7875 (from DTR) and at the sharpest focus I don’t get a single spot, there is a lot of non focused scattered light on both sides of the central spot. My camera doesn’t pick up the focused spot very well but you can see the scattered light. Do you get just a clear small spot when focused with the 3 element lens? Maybe I have a problem with my lens too. FYI, the photo is at fan speed = 1.
Thanks,
I can only comment on the speed issue.
2 things it could be. Do you mean 500mm/sec? That would be way to fast and it would slow down and speed up. But if you are meaning 500mm/min=8mm/sec which is plently slow. So then if the z axis is moving it would slow it down to match.
The setting in 3dpBurner Image2Gcode (MPCNC Version) is in mm/min and I tried 500 and 1000. There is no Z-axis movement when lasing a picture.
I guess I’ll just have to play with it some more.
You set your current to 2.5amps? You’re gonna burn that diode up pretty quick at that level. How far is the laser from the object being etched? In your first pic it looks like close to six inches. These lasers focus at about 2 inches. Move it to that distance and go from there. A fine adjustment can be done by screwing or unscrewing the lens a little at a time. You told me you burned your first laser before i posted my guide and it wasn’t an ndb7875 diode either right? Where did you get The2.5 amp setting from?
Wow I’m losing it. I thought i read a post from you about using a dumm load to set the current and using a setting of 2.5 amps.now i can’t find it.was that you?
Sorry, I mis-spoke. I set the current at 1.7 Amps. I did move it down to about 60mm in the above picture. Yeah, I’ve been adjusting the lens at a few different heights. Not much difference. I’m going to go try again shortly. I’ve also checked the lens to be sure it wasn’t dirty. No, the first one wasn’t a ndb7875.
Yeah, I tried to attach a picture and then the post vanished. I’m not real happy with how this forum works.
How much current does your power supply run? I2g gcode runs at fixed speed. Laser shouldn’t have anything to do with the movement.
I got my 2.8W $100 laser working pretty good now, here’s the video link.
It is a Nichia NDB7875 with a G2 lens from DTR laser shop. It’s running on a generic Chinese laser driver tuned to 6.5v @ 1.7 amps.
@leo69, I’m using a 25 amp 12v regulated power supply. Thanks for your great guide.
Very Nice Tony! I like the acrylic enclosure in the second video:) I know you had some movement/focus issues. Can you share what you did to resolve them? Might help others. Thanks for posting.
I made the shield with a piece of 1/8" AMBER ACRYLIC PLEXIGLASS - COLOR #2422 I got on eBay. It’s held to the laser heatsink with a couple neodymium magnets.
The focus issue was not using something solid as the test surface, I was using pine and it scattered too much of the beam.