Advice Needed for Laser and Paint Filling

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It didn't occur to me that you didn't have a lasercutter yet, but if you are at the stage of contemplating purchasing one, you might wonder whether you are better off with a CNC router. Those engrave as well, and infilling is definitely no problem.
 
Jarno

Thanks a lot for your suggestion but I actually already have a CNC :)
It's a DIY beauty with a 600x350 bed, Nema 3A stepper motors, linear bearing ball screws, all aluminium made with a Kress 1050FE spindle controlled by Mach3, that weighs about 100kgs. The problem is that I've moved to a different flat and I don't have my workshop anymore, and it's noisy and messy. I've considered building a soundproof box and decouple it from the floor with some neoprene feet and I'll probably get myself to doing that at some point this year but I have been bitten by the laser mosquito in the mean time and all my body aches and itches to have one....aaargh!!! ;)

 
Finally I ordered one of those small laser engravers, 5W, 445nm light, which seems to be better to anodized aluminium I read somewhere.

200€ is cheap as hell, and if it doesn't meet my requirements, it's always a nice gift for my nephew, who just started a robotics course for kids.

I've seen also an interesting way to etch pcb's, instead using photosensitive boards and UV exposure boxes, some people cover the copper with regular spray black paint and burns the design with the laser, then etch it as usual.

I see lot of advantages over isolation milling, which is not efficient actually, the main problem would be to keep proper alignment to drill and cut in the CNC router, nothing you can't overcome with some clever fixture system...

Any experience on this?
 
dirtyhanfri said:
Finally I ordered one of those small laser engravers, 5W, 445nm light, which seems to be better to anodized aluminium I read somewhere.

I also ordered today!!! I'm all excited like a schoolgirl!!! :)

dirtyhanfri said:
I've seen also an interesting way to etch pcb's, instead using photosensitive boards and UV exposure boxes, some people cover the copper with regular spray black paint and burns the design with the laser, then etch it as usual.

That's exactly what I saw too and I think it's way easier than going with UV, etc...

dirtyhanfri said:
I see lot of advantages over isolation milling, which is not efficient actually,

What do you mean by "isolation milling"?

dirtyhanfri said:
the main problem would be to keep proper alignment to drill and cut in the CNC router, nothing you can't overcome with some clever fixture system...
Any experience on this?

You mean using 2 heads, one for laser and the other for rotary? Personally I don't have experience with that but I've seen someone use it attaching a diode laser to the same piece that holds the spindle. The only thing is that you have to calculate the offset between each head to be able to use one or the other, OR do the rotary jobs first, then home the machine and do the laser jobs but you will need a red dot positioning led for that to work.

Cheers
Sono
 
My idea is to use two different machines, not attaching a diode to an existing machine.

With isolation milling I mean using the CNC router to mill the isolation between traces in the pcb.

 
Oh I see, sorry I didn't understand you the first time :)
Well I've never done that but I guess you'd need a jig and make sure you home both machines at the same point on that jig.
I don't know if in the real world that would work with very precise and tiny things though...
 
Well, I assembled the machine yesterday and took a bit of time to play with it....


The first thing to say is the fast delivery and the lack of proper documentation about wiring...

Despite that.

Damn! This is powerful, I'm having troubles to make it work properly (it keeps laser turned on forever making impossible to work with it) but hopefully nothing serious, anyway, it burns paper and wood as nothing, and marks anodized aluminum clearly with one pass, shiny with two passes.

I think it will work with black paint on pcbs too...

Quite happy with the machine, even with the  always on problem, which I think is just about wiring or configuration and should be solved in the next few days.
 
Hi all

Sorry, I'll be the shithead here... in a parallel life I'm used to work with laser for interferometry as other application...
I have only a quick read of the topic so maybe I'm missing  some points but as we are in a DIY forum and as I read laser power way over mW range, drastic safety rules may apply especially with invisible spectral ray like CO2 laser !!!
Please inform yourself with those safety rules and buy protective glasses (according to your laser ray) if you work in "open" room, to avoid any dangerous reflective beam !!!
Over mW you can have trouble, over W you can get blind before you understand what happen...
Be safe...

Best
Zam

 
Thanks for the advice Zam.

The machine  comes with protective glasses, anyway, I'll build an wooden enclosure for it for keep my eyes safe. Also in my workshop I receive frequently visitors, so I'll try not to blind them.

I'm not familiar with lasers and possible hazards, but as I saw the results yesterday I was thinking what the hell could do that beam to my eyes.

Thanks for the advice again, as safety advices are never too much.
 
I've been doing further test and I'm still impressed with the machine.

It engraves anodized aluminum perfectly as well as powder coated surfaces.

I want to try with pcbs, but if it burns powder coat I bet regular paint won't be a problem.

Enclosure and air extraction are absolutely needed.
 
Wow, that's very reasonably priced compared to a engraving spindle setup.

I guess I never considered it because I wanted machining capabilities. Now a few years on I've figured out ways to do a lot of the drilling by hand. I could mark everything out with the laser cutter and drill what I need to drill by hand. Hmm.
 
rock soderstrom said:
Interesting topic! Please keep us informed!

I'll open a new thread  with the whole process as I think it goes further than this topic.

Gold said:
Wow, that's very reasonably priced compared to a engraving spindle setup.

I guess I never considered it because I wanted machining capabilities. Now a few years on I've figured out ways to do a lot of the drilling by hand. I could mark everything out with the laser cutter and drill what I need to drill by hand. Hmm.

I'm not sure if it will fully replace the engrave capabilities of my router. It just removes a thin layer from the surface.

Finishing and resolution seems better than traditional engraving.

But I don't regret about buying a new CNC router two months ago. just different animals.

I'm not sure about ink filling in laser engraved surfaces. With traditional engraving I take off like 0.1-0.15mm of material, that depth contains paint, with laser I remove like 15um (theoricaly that's the depth of the anodisation layer, I could expect even less in my own anodized pieces) which is 0.015mm,, not sure if paint will be retained there...
 
My new chinese 50W laser cutter/engraver just arrived this weekend and I've been installing it....I keep fingers crossed for it to fire up ok on first start...  :)

 

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Good luck. It's a painful process, but the "rush" of something working is worth it.

Make sure you have adequate ventilation, and be careful which materials you cut. Things like PVC can create chlorine gas.

From hackaday : https://hackaday.com/2015/03/14/how-to-identify-plastics-before-laser-cutting-them/

There are several reasons why you don’t want to cut or engrave some types of materials. A few make a gooey mess that you’ll regret even trying. Others make a horrendous odor. Some hackerspaces will even charge you extra if you stink up the place (aka: malodorous material charge.) Some tend to catch on fire. Yikes.

But that’s not the worst of it. Some types of plastic release potentially deadly hydrogen chloride gas. It’s bad for the optics, it’s wreaks havoc on the electronics and mechanics of the machine, and could do a really good job of messing up your lungs forever. In the video after the break, you can see the flame test for such plastics in action at the NYC Resistor as they test several common items using nothing more than a blow torch and some copper wire. In short, if the flame test produces a green flame, do not put it in the laser.

I use a lot of amazon cardboard boxes to begin with. it cuts fast and clean, and is enoguh to test if my PCB's line up etc.
Then I move on to 3mm plywood. (https://www.amazon.com/12-Premium-Baltic-Birch-Plywood/dp/B013NT3OAC/ref=sr_1_2?ie=UTF8&qid=1506951431&sr=8-2&keywords=3mm+1%2F8%22+plywood) - takes  alittle longer to cut, but stronger.
Then I finally use 3mm cast acrylic, designer to be used in signs etc.

/Dafydd
 
dirtyhanfri said:
I'm not sure if it will fully replace the engrave capabilities of my router. It just removes a thin layer from the surface.

Finishing and resolution seems better than traditional engraving.

I wouldn't expect it to do everything a router would do.  The price sure is right. For marking powder coated panels it seems like a good choice.  I can set up a jig for a hand router if I need to bevel an edge or make a square hole. I have a micromill for little stuff. I have hole saws for VU meter holes.
 
Id love to see some examples guys. Even your shit practice work.  I've been intrigued by this for awhile now and I'm excited you took the leap.
 
Rocinante said:
Id love to see some examples guys. Even your sh*t practice work.  I've been intrigued by this for awhile now and I'm excited you took the leap.
I have done all Panels in this Thread using a 50W CO2 Laser:
https://groupdiy.com/index.php?topic=66411.0
 
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