Beginners Guide to Laser Power and Speed

[@TerraMarie34]

I recently got a omtech k-40 and I’ve basically exclusively been cutting 1/4 wood and 1/4 mdf with it. I just cut 1/8 for the first time today actually. 2 passes is enough for me to get through all 1/4th. I do get charred edges, but that’s nothing a little sanding can’t fix. I paint everything I cut so that charring is never worth sanding to me. But it is possible and not as hard or intimidating as one would expect.

[@SteveMakesEverything]

If you are doing multiple passes anyway, try to do 4 passes but almost double the speed and you should have less charring. MDF is generally bad for charring, but you can eliminate some of it by going faster with more passes.

[@PinItRight1]

Thanks, Steve, very helpful. And yes, that is where we got our MDF from 🥴. Jerry and Chris

[@SteveMakesEverything]

Thanks for inspiring this video Jerry. I'm always happy to help😀

[@TalkingGIJoe]

When you say "40watt" laser won't cut MDF... is that 40watt input or output power? It seems that these Chinese laser system guys purposefully obfuscate input power with laser output power. I see a whole lot of 5.5watt output lasers labeled as 80watt lasers. Any guidance there?

[@SteveMakesEverything]

In CO2 lasers they tend to specify the peak wattage of the tube, so they are cooking the books a bit. In terms of real output a typical 40w laser is usually closer to 35w of real laser output. On my own laser with a 90w tube, the output based on power supply output voltage and measured current can be calculated at 70W of useable power. For diode lasers the power claims used to be all over the place, but the industry does seem to be moving toward actual laser light output power so they typically claim anywhere from 5.5-10w

[@RandomProjects2112]

Thanks for the video! Where in Canada did you purchase the laser ready cherry MDF core plywood?

[@SteveMakesEverything]

You can buy laser-grade hardwood/MDF plywood from Trotec's engraving-supply site.

[@weboflies999]

I guess what we would want with RE3 is something like "group attributes" that can be selected to overide individual attributes.

[@SteveMakesEverything]

Yes! See my newest video where I talk about this

[@turboflush]

Good stuff. Similar to how i do it. I dont fully understand the powerscale and got strange results. Cutting powerscales seem to be more rare. I ran a powerscale on my 5w diode laser and had great success.. But on the 100.. Idk what happened. 1/8" mdf @ 60% 100w laser. I need to play with it still.. Edges are a bit gummy after.

[@SteveMakesEverything]

For power, create or download a test similar to the one in this video. This will tell you the best power vs speed settings. On an FSL laser with RE3 you have the added dimension of current to confuse things and a couple people have asked for a video to discuss this, if your 100W laser is a Titan or a PS, then look for that coming up

[@turboflush]

@@SteveMakesEverything Sorry. For some reason i dont understand much of what you said

[@SteveMakesEverything]

@@turboflush Gee, maybe I should learn to type - or at least read what I'm posting 😀. At any rate I'll do a video this week to talk about the difference between power and current in RE3

[@azmanyaacob1]

Thanks for ur sharing... really appreciate it

[@SteveMakesEverything]

My pleasure

[@Cambium29]

I use almost exclusively 3mm MDF. On a 45w Pro-series FSL, I use the following settings with minimal char and staining. Takes only a wipe with damp paper towel to remove any yellowing. To Cut: 60sp, 95pwr, 100cur, 4 passes To Engrave: 70sp, 30pwr, 100cur, 1 pass

[@SteveMakesEverything]

These should be decent settings. It's the multi-passes that makes it possible.

[@bricomama16]

Hi, sorry for jumping in, but when you say 60sp what's that measurement? what would that be in mm/min??

[@SteveMakesEverything]

@@bricomama16 On a laser running RE3, this would represent 60% speed. If you are using something like Lightburn then you typically work in mm/min or in/min

[@turboflush]

@@SteveMakesEverything i always understood mm/s for co2 and mm\m for diode.

[@SteveMakesEverything]

@@turboflush In RE3, FSL made a choice to use percentages rather than actual speeds. Being a man of the world I can adapt to either, thogh I prefer the exactness of distance over time

[@kpedro161]

So you get ZERO smell ??????? I am moving over 1000 cfm but still get a slight smell during use on birch

[@SteveMakesEverything]

This would depend very much on how well your laser is sealed. Air intake and exhaust need to be controlled properly or fumes will leak - even slightly. Minor smell should be ok

[@kpedro161]

Another great nugget of wisdom from you Steve. Thank you. I run an in-line exhaust fan adding an additional 240 cam of exhaust effort to the system fan and then in to my FSL100 fume extractor. When running this test from you on some plywood, I am getting some pretty good smell in the workshop. No smoke just smells. Are you getting some smells from your Muse 3D and is this just normal? Thank you for all of your help.

[@SteveMakesEverything]

I think this would depend on the kind of material you are using. I don’t get any smell/smoke but my laser moves a lot of air and my exhaust pipe is only about a foot long

[@whynotcnc8828]

thanks

[@SteveMakesEverything]

You're welcome!

[@BrendaDavis-1963]

I’m new

[@SteveMakesEverything]

Welcome. We're all here to help.

[@BrendaDavis-1963]

@@SteveMakesEverything thank you I just tried to do a material test for plywood like 3MM and I got a error message saying loose but it’s not it’s not supposed to do. It is rejecting to do the test.

[@SteveMakesEverything]

@@BrendaDavis-1963 Can you explain this a bit more?

[@BrendaDavis-1963]

@@SteveMakesEverything I tried doing a material burn setting, but it’s not letting me do it. I don’t know if I’m doing something wrong. Do you have to put in the speed and the power or does it just automatically just run material test itself? I don’t know I’m just so I don’t really know.

[@SteveMakesEverything]

@@BrendaDavis-1963 You really need to enter all the values there to get a good test. Watch this video: kzbin.info/www/bejne/mXPVqJtrpbF2nrs

[@spydie]

Not enough output out of the laser is not too far-fetched. I bought a new Ortur Laser Master Pro 2 S2 LF and it takes 6 passes to cut through 1/8" wood while other guys can do it in 1 pass. Ortur had me run a test for them and they decided I needed a new laser head, but with Chinese New Years (a full month) I'll be waiting forever to get the laser.

[@SteveMakesEverything]

Diode lasers generally have much less power than a typical CO2 laser so it isn’t unreasonable to expect to do multiple passes. Some diode laser models definitely provide better technology than others. In your case it sounds like the module is just faulty. 10W laser modules tend to pair two 5 watt lasers into one box and in your case one of them might have failed

[@spydie]

@@SteveMakesEverything No, it's just a 5 watt laser, so one couldn't have failed. Although I have no idea why it's not putting out what it should, but I know mine is putting out a lot less than other guys testing that same laser on KZbin. I've seen other guys guys cut through 1/4" (5mm) wood in 2 passes with this same 5 watt laser. If it takes 6 passes to cut through 1/8" (3mm) wood with mine, I'd never be able to cut through 1/4" so something is definitely wrong.

[@SteveMakesEverything]

@@spydie Definitely sounds like it. If you haven't already, make sure the optic where the laser beam comes out of the module is clean. It's a long shot but if it's dirty your power will be greatly reduced.

[@spydie]

@@SteveMakesEverything Hi Steve, yes, I checked and cleaned it, but it was like that (no power) from the day I got it. I didn't know it should have more power. I was just disappointed that it was so weak. then I watched several reviews on KZbin and guys running cutting tests and that's when I realized mine was running at about half the power everyone else's was. I hope the new laser will fix it, if not, then I have to assume there's something wrong with the mother-board? Those are really the only two things that control the power, well, that and Lightburn, but I know I have the settings all correct. I wish Ortur would offer a 10 watt option. There's no substitute for horsepower! LOL

[@SteveMakesEverything]

@@spydie FWIW I think I'll have a review of a 10W diode laser coming up soon so watch for that. Even assuming your laser was working correctly, 5W is just a bit limited for cutting material. Hopefull Ortur gets your fixed for you though.