LASERS...I could use some info

I don’t know if it’s any easier. I was able to make a board using my MPCNC and the router using one of the really small 10 degree etching bits. It was a PITA getting the board level for cutting such a small depth. I thought a laser might be easier.

If I find one. I just got one that will not focus as the lens just sits in by the pressure of an o-ring.

Nice, noted. Difficult for a few reasons but I bet there are some lists out there I can just link?? Maybe just pull a basic list from them.

“long to even react to blink if it” maybe “long to even react by blinking if it”
“will try to take of the glasses immediately” to “will try to take off the glasses immediately”
“for reasons I do not understand fully” no suggestion, only a comment. IIRC the issue is the point source for the laser. Diodes provide a large source for a larger wattage, you want to lase with a beam that is as close to parallel as possible and the wider the beam the more the power is spread over the surface. If the diode were giving a true point source we could focus to a point, since it’s not even perfect optics are only going to focus to a dot.
“Endurance Laser also have a great selection” should be “Endurance Laser also has a great selection”
“PWM, TTL” uh, PWM is TTL, voltage is separate. Analog vs. digital makes more sense, the three possibilities are “ON/OFF” (either 5V or 12V TTL), PWM (either 5V or 12V, 256 levels) and analog (0-5V or 0-12V, usually 256 levels).
“Configuration_adv.h (Lines ~1555-1580)” should be “Configuration_adv.h (Near lines ~1555-1580)” since it might change before 2.0 is released.
“change is to make line 150 read, #define” should be “change is to make line 1570 read, #define

Dangit, Bill, this is my second round of revisions, I thought for sure we were going to get it fixed up before you saw it…I tried.

I suspect this too. Since the source is larger, the same lens will make it be larger where it focuses. Similar to a larger hole in a pinhole camera… I think… Who knows?

TTL actually means 5V. Not necessarily PWM, just that 5V is true and 0V is false. In this case, Ryan needs to try to match the description of the devices, not something more universal like what you’ve laid out.

Actually I looked it up. There’s no voltage in the TTL spec, it’s just that the common voltage in use at the time was 5V. TTL defines the signal type, not he voltage needed.

Okay I think I have those fixes in.

The ttl part is more of a “this is being misused” type of thing. On ali it is being used as a keyword, some sites use it as a power rating, etc. I was trying to imply looking at the specs more than the key title words. Most say all of them. Basically all you need to know is if it expects 12V or 5V. I do think there are some really generic ones that are using the power to control it not an actual signal…but cross that bridge if needed.

Side note. I appreciate you all helping me with my stupid grammer and spelling issues. I used to not do this because of how many mistakes I made. People jumping in and helping out in a cool manner really make it easy for me to just get it out and fix it later. High five.

So maybe I add,

The most common control methods with RepRap boards are both 12V PWM and 5V TTL (Some are 3V but should still work).

?

The EleksMaker LA03-3500 450nm 3.5W Blue Laser Module is currently on sale at Banggood for $70. I’ve got two more days to pull the trigger on that. I’d like to make sure I get everything I need, including safety gear.

David, since you have experience with these lasers, are there certain glasses or anything else I should get along with it?

 

So I think that is the one I have. If you go to the elksmaker site, they show those as being fake. As in theirs are only the more expensive blue ones.

 

All,

I really have had nothing but good luck with the Banggood/Eleksmaker lasers – both the 2.5 and 3.5 watt units. I’ve ordered 5 of them so far IIRC and they have all worked as advertised.

Heath, that appears to be the same 3.5 watt units I have ordered in the past. As I said, they have all worked flawlessly for me… and I’ve been able to focus them all to 55mm or so without issue. I almost always use a printed shroud/air assist with mine.

Ryan, I’m truly sorry you got a bad unit… and know nothing of any “fake” warnings. Can you elaborate?

Alright, I’m going to join the fray… [from memory,] back in the late 60’s and early 70’s, integrated circuits and digital logic were just coming on the scene and there was a rapid progression in the technology – RTL (resistor-transistor logic), then DTL (diode-transistor logic), then TTL (transistor-transistor logic) and, later, CMOS digital logic. I started with purely vacuum tube systems as a technician in the Navy, then hybrid systems (transistor/IC low power sections with vacuum tube power stages) as an avionics/radar tech as a civilian, and the aforementioned IC progression as I studied EE when I went back to school. Upon graduation, I went into industry working as a design engineer in the defense industry… where standard TTL and then LS-TTL (low-power TTL) reigned supreme. I designed MUCH discrete logic circuitry using the TTL/LSTTL family of devices before the advent of the larger-scale integrated circuits that are common today. AT THAT TIME… the term TTL spoke to the logic levels used, 0v-5v.

It appears that “TTL” has lost it’s identity as a logic level and is now identified loosely, with some diode laser manufacturers, with the modulation method… with 5v and 12v versions being commonly available. It seems to me that PWM best describes the modulation method – regardless of the voltage levels – and TTL generally implies the 0v-5v version. The 12v version is still PWM, just not TTL.

The Banggood lasers I’ve gotten with “TTL modulation” have indeed been the 5v PWM variety… and I’ve had to remap the 12v D9 fan output (a PWM signal) to a signal pin outputting 5v PWM, using M106 Sxxx and M107 to control the laser’s intensity/power.

This is indeed the way it WAS (as best I can remember), so I’m sticking with it… :wink:

My $0.02.

– David

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Definitely nothing against you, I tried it and no harm done. I will figure out a fix good enough to do something with it.

Yeah I have no idea what is going on with them, the site actually links to the banggood page, but this page says those lasers are not theirs…

http://wiki.eleksmaker.com/doku.php

Who knows, the rep that is emailing me is from a banggood email, not eleksmaker, so confusing.

 

Interesting. I’d not seen that…

 

David, do you have any particular safety goggles you would recommend?

 

Heath,

I doubt you could go wrong with the goggles from JTechPhotonics… I’d trust them completely. I have a cheapy pair from I don’t remember where… and a nicer pair from JTech IIRC. I suspect the $25 ones from this page would be just fine…

– David

Long time lurker, first time poster, total newbie. Logged in to the forum to say:

Thank you for writing up the laser page.

The info on the page is very informative, and helped give direction as I work on the mpcnc project.

Since you asked for feedback, a couple notes:

  • I liked the comment above that if you're trying to cut 1/4" plywood, you might be just as well using a router instead of a laser. Obviously different finishes, applications, but this struck a chord for me. Lasers are cool and all, but nice to hear an opinion that also accounts for workflow and efficiency.
  • Safety section up front is good. It caused me to 'tap the brakes' when thinking about diving in to the laser stuff.
  • Perhaps obvious, but another safety concern worth mentioning up-front is fire. The few times I've used a production-grade laser cutter (Epilog), the thing would flame up when cutting plywood, and you'd have a fire on your hands if the vent fan wasn't turned on. Maybe not as big of a concern with smaller diode lasers (no experience myself), but it can be with the bigger CO2 lasers.
I look forward to seeing the laser page fill out.

I just started printing the parts for the mpcnc, looking forward to learning more.

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Added, thank you!

Does anybody know, what kind (spacing) of JST connectors (and crimps) are compatible with the drivers boards, described in Leo69’s tutorial? I’ve received the board, but it’s missing the connector for the power supply and the TTL connection. Thank you.

My Banggood 3.5w laser arrived yesterday. I may be asking for help with it soon. Do you have a recommended mount from Thingiverse?

 

Pictures help there are tons of 3.5W lasers.