CNC 3018 Router and Laser Kit- Part 1

Can This Inexpensive CNC Laser Be Used to Engrave Stainless Steel? (For Knifemakers)


I've been watching some videos online while looking for a reasonable way to mark my knives with my logo or add the steel type or a special message as requested by the customer. A laser comes to mind and it would mean no more custom stencils and electrolyte. Plus, branding leather and wood for promotional materials would be crazy amazing. However, it seems that not all the budget lasers can mark steel. In fact most ultra-cheap desktop lasers cannot do much more than cut paper. 

After much research and some help from Santa Claus I ordered this CNC 3018 Woodpecker Kit w/5500 mW Laser. The laser is a 450 nm (blue) diode type.

OK, the ad clearly states it cannot be used to engrave metals, but some clever folks on YouTube are marking stainless steel with lower power blue lasers. For example, the guys at HEVE are working their marking product with a 4000 mW blue laser and the results look perfectly acceptable for a typical knifemaker's application. See video.




The marking coating is fused on to the steel by the laser. These products can be seriously expensive, e.g. $75 for an aerosol can (Cermark). Others have had success with the using dry moly lube like CRC Dry Moly or Prime-Line's RZ-50. Generally these coatings contain molybdenum and seem to mark fairly well on stainless steel. 

In the experimental realm we have Dijon mustard being used with low powered blue lasers to mark stainless steel.




Yes, mustard on stainless steel with 4 Watt  diode laser: 

https://www.youtube.com/watch?v=B60nXwhK9gk



The goal here is to see what we can and can't do with a budget desktop CNC laser from a knifemaker's perspective.

Now into the Nuts and Bolts


The packaging is pretty well laid out with two layers of foam tray. Nothing appears to be broken or bent at this stage.










Unpacking left me with lots of little clear plastic bags. Nothing identifying what's in them but we should be able to figure this out from the pictures right?

The frame is extruded aluminum akin to 80/20. Some metric hex wrenches are included.





In the box there is a little CD with files. One of the files is a Word document that has some CAD images and rudimentary descriptions.









Getting the hang of putting the angle blocks in.













The tee nuts can be a little tricky in tight corners like this. Having someone with small hands to help is a plus.









The table is a surprisingly hefty chunk of extrusion. There are four slide bearings that roll along the polished rods. Making sure the rods are as perfectly parallel as possible is the big challenge here. as there is no step-by-step it was kind of trial and error to get the table sliding smoothly, yet not loose on the slide bearings.





Here the base, table and gantry are assembled. About three hours in so far. I look forward to getting the rest of it finished this weekend.



Next up will be installing the stepper motors, lead screws, router motor and installing the PCB.




The stepper motors are coupled to the lead screws with these anodized couplers.










The whole traveling head assembly slides on the X axis on two polished rods driven by the X stepper motor on the right side of the gantry.












The GRBL 0.9 "Woodpecker" board mounts on four nylon standoffs. Yes with tee nuts.









Wiring is as simple as plugging in the motor and the three stepper motors.








This is the laser module. However, there is no detail on how to mount this thing to the traveling head. Hmm, going to have to think something up I am afraid.


In the meantime, let's get the software installed and check out the router operation.





UPDATE: I have found that the laser module is meant to replace the engraving motor. Also, when testing the movement of the three axis, I found that it was very hard to turn the table  "Y-axis" motor and lead screw. This is a result from the lead screw nut not being installed truly.


To remedy this, I threaded the lead screw into the nut and heated the screw with a torch close to the nut. This softened the thermoplastic and I could nudge the nut so the lead screw is now parallel with the base of the nut holder.







After digging deeper into the supplied CD ROM, I discovered that the laser is to be mounted where the spindle motor goes. This wasn't what I was expecting. This means the machine is setup either as a laser or a router depending on which tool is installed and plugged in to the board.

I may look into making a bracket for the laser module and attaching it to the side of the motor clamp. This way there is only software switching between tools.



The only remaining issue is how to mount the laser module power supply board.










Next is the software setup and trials.

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