Installing 6W Laser with Magnetic Docking onto CNC Machine (PLH3D-6W-XF from Opt Laser)


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I’ve been kindly sent a 6w laser by a Polish company called Optlaser. It’s quite an interesting looking object with several through holes at the base to help cool the module while removing fumes. It looks very futuristic, and almost like it should belong on a spaceship.

In addition to this I’ve been sent a magnetic docking station, which means the laser module can be removed and stored for safe keeping. This is particularly useful if you plan to install this on a CNC router as the dust produced can damage the optics of the laser. I’ve also received some nifty safety goggles, a hood attachment which fits around collimator lens and channels fumes and smoke from the laser beam, and an additional collimator lens. So the one on the laser module is for finer work while the spare one produces a courser beam for faster engraving.

I want to use this on the CNC router I have been working on but I also have the reminisce of the xcarve and its belt driven system might work better for laser engraving.

So before I start – please be aware that lasers are not toys, bla bla bla. Please do your own research before playing around with something that can knock your eyeballs for six.

I’m going to try and get started with installing this laser engraver onto my CNC machine. Although I’m not entirely sure how I’m going to do this. I did receive some diagrams with the parts, and I think there might be a little bit more on their website. Essentially what I’m going to do now is fit this section here which is the quick release plate so the idea behind this if you’re going to install this onto a machine that also has a router the saw dust created from the router can actually effect the laser. It can build up on the optics and degrade the cut essentially.

The first thing I’m going to do is wire the laser to the magnetic docking station. I undo the wires from the barrier block and replace them into the green terminal connector. You really need to pay attention while doing this so you don’t accidentally cross wires and fry the components.

Ok be careful not to over-tighten these. That goes in like that.

These are really well made – well machined pieces. They have a strong positive hold and the instructions are pretty clear.

So I’m sort in the process of re-cutting out my plates in aluminium. Ideally, I should try think ahead and plan how to mount the laser, so I can avoid future headaches. But that’s a separate video and before I do this I’m going to double check the wiring within my controller.

When I made the controller I wired the four PWM and Spindle Enable pins from the controller to a 4PDT on-off-on toggle switch. One half went to the VFD and spindle, and the other went to the RX16 panel socket mount. What I should have done with this was actually wire only the PWM and the ground, and then also… erm.

I wanted to have the option of adding a laser, but I didn’t really know what I was doing or how I would wire this. This laser has a controller built in, and it can accept ANG or TTL inputs. Both can be used as PWM. Pulse width modulation. I don’t need the spindle enable pins to reach the laser module, so I un-soldered those and wired up the power to the laser. You can use 12-24v but you need to ensure the Power Supply Unit can provide a minimal current which is either 2.5 Amps for 12v or 1.5 Amps for 24v. I’m going to wire in the 24v.

Errr, I’ll just turn it on. In the end I tried a few different wiring techniques including wiring the power directly to the GX16 socket. This resulted in the fan constantly running. You guys can look at the laser.

In the end I decided to separate the power and signal to the laser via two switches. That way I had two physical actions to complete, not including putting the laser module onto the docking station before starting a laser job. If I forget to do any one of those things the laser will not turn on.

How you control the laser is determined by the software you are using, and the firmware you have installed on your controller. I am using GRBL 1.1 which now has a Laser Mode written into it – which acts like a safety feature. $31=1 activates laser mode, $32=0 turns it off. These can be written into the Gcode before running a job.

So what I’ve got now is a switch which sends the 24v to the laser plus a switch which sends the signal either to the laser or the VFD and then the spindle. So if I switch over to the laser it wont turn on until I put the power switch. And then if I swap over to the router this will automatically turn off. Anyway I’m going to try draw this up now so I’ve got a record of what I’ve done.

The next thing I did was check the laser along a toolpath. I used a demo/beta version of a G-Code generator by OptLaser which at the time of filming this software isn’t available yet but I think it’s going to be a contender. It looks very intuitive to use. I’m checking to make sure that when the laser mode is enabled, the laser turns off when the machine comes to a standstill. Otherwise I’d burn a hole in the waste-board.

I can’t stress the safety aspect of working with lasers. You really need to be wearing the correct safety goggles which blocks the wavelength range from the laser. You need good extraction coz lasering anything stinks and can produce dangerous TVOC’s– you need to understand how air pressure works so that when you’re extracting fumes from your work area you are replacing the air in the room from a fresh clean source. You’ll probably need a carbon air scrubber as well. I am considering making an enclosure for this machine or at least make an additional hood that can fit around the laser beam, using the appropriately tinted acrylic. There’s probably more things you need to consider as well that I haven’t even fathomed… I turn this on and hide behind my enclosure.

And the thing I have to remember is to check that the laser mode has been disabled. So it’s $32=0 to do that. It’s in the code to switch to it and switch back but if something goes wrong and I don’t finish then potentially the machine will be left on that setting and if I switch to the router, and try to cut something and the spindle stops spinning when it (the feed) slows down well  I’ll look like an idiot.

I’m now 3D printing a part to mount the laser too the CNC machine. I made a quick model on Fusion 360 but I’m not going to show you how I did that otherwise this video would be 10 minutes longer.

Well the holes look like they line up.

If you are interested in that I have a similar video making a replacement bracket for a dial gauge on my main channel – which I’ll link too in the information card. Anyway I printed this out and test the design, only to realise I made a few mistakes and had to make a second one. For example, the recess holes for the nuts were a little too tight… and overall the laser was too high above the wasteboard.

I just put the the wire through the drag-chain, and it fits like that. The only problem is it’s really high up.

To get the full power of the beam you should mount it about 20-30mm above the material you are working on. I kept the holes in the same position as I had already tapped the spindle acetal plates and fitted everything together. I also added some boot ferrets to the wiring just to make it all a little more secure. I also added some boot ferrells to the wiring which I previously secured directly to the flex.

I then did some test engravings… Ok I’ve got the fan over there. It’s not long enough to reach over here but what I could do is.  To focus the laser I would run a tool path and then press the pause button, and also turning the laser off at the power selector switch and then toggle the collimator lens one way and then continue cutting. I did this a few times until I was in focus.

Alternatively you could write your own g code to move the laser in stages along the z axis while engraving and compare the outcome. Picking the best one and working out the offset from the z axis home.

So to conclude this is nicely made bit of kit and it seems to work quite well, especially with the latest version of GRBL. The guys behind this seem quite knowledgeable, and I have to admit I really like the aesthetics – it’s quite sci-fi and it looks like it should belong on a spaceship.

If you are interested in knowing more about the module or docking station, I will place an affiliated link in the description. And hopefully by the time you see this video their software will also be available but if not you could always use LaserGRBL – which is a free alternative and I will leave a link to that in the description as well.

Anyway as per usual please let me know your thoughts on laser engraving, cheese, the weather and the growing costs of birch-ply. And don’t forget to sacrifice a thumb and I will cheese you in the next one.

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