Casually Laser-Exposing 0.2 mm PCB features on a 3D printer

much appreciated yours :)

Marco Reps

much appreciated your help

Ok Thanks

Use a voltage divider calculator to make something with resistor values you have available: <a href="http://www.ohmslawcalculator.com/voltage-divider-calculator" rel="nofollow noopener" target="_blank">http://www.ohmslawcalculator.com/voltage-divider-calculator</a> Like R1=1kOhm R2=250 Ohm for example. Doesn't have to be precisely 5V, but I'd aim lower rather than higher

Marco Reps

the fan speed is adjustable from gcode (octoprint), and also from 3d printer console. Yes I useed L7805.But if I need something fast. can you please frow some examples to start from

Like a 7805? That can't work because it doesn't understand fast switching signals AND it needs a minimum load to slowly settle down to the correct output voltage. You need something fast like a logic level shifter, opto-coupler or resistor divider

Marco Reps

If the fan speed is adjustable from gcode, you can use that output pin for the laser, might also have to be level shifted to 5V... Join the discord server for a better chat system, this is too uncomfortable

Marco Reps

Oh sorry my Pam has 24v output, so I use voltage regulator to step down to 5v. ttl on laser drive supports only 5v

24V TTL output from your printer? Never seen anything like that. If true, you could use a resistor voltage divider (<a href="http://hyperphysics.phy-astr.gsu.edu/hbase/electric/voldiv.html)" rel="nofollow noopener" target="_blank">http://hyperphysics.phy-astr.gsu.edu/hbase/electric/voldiv.html)</a> to get it to 5V

Marco Reps

Also my printer next to extruder have e-motor, heater, temp, fan, and x-min ports

I try use PWM for output on TTL. my printer ttl port has 24v output, so I use power regulator to reduce to 5v. I think that ttl ports only supports 5v

"Built-in" wasn't the right thing to say :) I meant the external circuit board with the TTL input, that's what you need. Now does your printer have an unused output pin, that you can program?

Marco Reps

I planning to use it with Wanhao i3 P 3d printer. also I unscrew fan, and found just laser, nothing else.

That has it all built-in I think. Are planning to use it with a Cetus3D printer or another printer?

Marco Reps

<a href="https://www.aliexpress.com/item/2-5w-high-power-450NM-focusing-blue-laser-module-laser-engraving-and-cutting-TTL-module-2500mw/32790785641.html?spm=a2g0s.9042311.0.0.uDutdr" rel="nofollow noopener" target="_blank">https://www.aliexpress.com/item/2-5w-high-power-450NM-focusing-blue-laser-module-laser-engraving-and-cutting-TTL-module-2500mw/32790785641.html?spm=a2g0s.9042311.0.0.uDutdr</a>

Link to the laser module?

Marco Reps

I can't see way to use PWM output, can you?

I can't see simply way to use PWM, in all this. My 2.5w laser come with only one driver board(external) not internal with T-, T+ and so on. I think easy way will be replace driver board.

Yeh, CC is what you need. You'll still need to find a way to connect the printers PWM output to it, but surely that'll be possible

Marco Reps

The LM317 looks like it only can handle up to 1.5A. but the LM350 handles up to 3A. Also I found Adjustable Power CC/CV Step-down Charge Module, that could do job. if thats is correct ?

Oh that might be a bit more difficult, the printer will probably not be able to drive a 2.5W laser directly. For the 0.3W module it is just enough. You'll have to build an external constant current source for a more powerful laser. This would be a good place to start: <a href="http://imajeenyus.com/electronics/20160530_adjustable_current_source/index.shtml" rel="nofollow noopener" target="_blank">http://imajeenyus.com/electronics/20160530_adjustable_current_source/index.shtml</a> MAYBE you can connect the printers unused 5V output to the adjust pin directly. If that kills your LM317 you have to use a voltage divider to drop 5V to 1.25V

Marco Reps

can I ask which resistor should I use with, to tray out

Theoretically yes, but 2.5W modules are usually blue 445 nm lasers which have a larger and oval dot. That could be corrected with special optics, but 405 nm lasers are much besser out-of-the-box

Marco Reps

Can that be done with 2.5w laser ?

No, haven't even tried it! Yes, voltage across the diode in comparison to voltage across the constant current source input (DC jack) would be an interesting measurement

Marco Reps

Ok, the laser module was discounted to 25€, soo.. its on its way here. Did you actually try using it with its own power supply? How would one test the delay on switching it on and off? scope to laser led and ground, second probe to power in, and start switching at different speeds? (stupid thing posts when I press enter. Grr.)

Marco Vujevic

It is possible to run the development version from sources, but it should really be done on OS that ends with x. On Windows it took about 3 hours to get all the dependencies, manually copy .dll files to the right location, then everything again for an older pyhton version ... I agree, they have to make a proper release asap, because the paint all feature is just the thing for laser machines. It works fine, too for real layouts. I guess my test layout was too artificially difficult ...

Marco Reps

I gave FlatCAM a try on your earlier recommendation. Thank you for that. The only problem I really found was having to manually "paint" each section to fill it as you mentioned. An optional "fill all" tool would be excellent but it seems the development hasn't released an update in well over a year. Also an option to select triggering a Mcode instead of a z move would be really handy.

Jon Raymond

It is an awesome machine for the price, isn't it? Below 500$ I'm not seeing any competition at all

Marco Reps

Yes, using the Z-axis to focus is very possible, but using that it to cover larger areas is a brilliant idea, that didn't cross my mind! Gotta try that some day.

Marco Reps

I’ve actually got the Cetus. So very nice relevant video. :) thank ya!

Jon Harsem

nice job!. I am wondering, could you use the Z axis to vary the focus of the laser (and so the exposure "dot" size") so coverage of large areas didn't require so many passes? One thing I noticed is that areas of fill are like "scribbled" and would result in random copper filaments in the larger areas where copper is to be removed (does it even?) I am loving this series of laser etching vids - I have an eleks maker - un-built yet because every time I get close, I see one of your vids on how to make it even better and that puts me back another week - you've got a lot to answer for ;)