# 45 Watt laser not burning as expected **URL:** \ **Category:** Everything Lasers\ **Created:** [February 14, 2026, 9:05pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770 "2026-02-14T21:05:11Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 14, 2026, 9:05pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/1 "2026-02-14T21:05:11Z")
Thanks Eric, I’ve been playing with the plywood setting on both 3mm and 6mm Baltic Birch… they didn’t even come close to cutting through (we’re talking a 0.5mm depth at most). What’s the best way to trouble shoot this? For reference, I triple checked that everything was correctly set to mm/s, and I’m using the 45w laser calibrated with the 21mm cube. Appreciate your guidance, ---
**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\ **Post date:** [February 15, 2026, 4:02am UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/2 "2026-02-15T04:02:25Z")
On a 45 watt laser that should be no problem. Not sure why you switched to mm/s. You don’t need to, you can use the imperial speeds that are in that chart. Regardless make sure your laser is properly focused on top of your material, when your laser is deployed (you can manually do this in the laser utilities menu) and you jog it down to Z zero your 21mm block should fit snugly between your material and the body of the laser (NOT the nozzle) also make sure the power switch on the laser is set to “II” and not “I” that switch reduces the power by 50% ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 4:07pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/3 "2026-02-16T16:07:16Z")
Hey Eric, I usually work in mm, just personal preference. In the sheet you shared mm/s (column e) is millimeters per second, correct? Regarding the z-offset, I did use the body of the laser, but I used the spoil board, not the top of the work surface. I will make this change. Regarding II vs I power… how can I see/switch this setting? ---
**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\ **Post date:** [February 16, 2026, 4:09pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/4 "2026-02-16T16:09:18Z")
> [@FunnerSurfCraft](#): > > I usually work in mm, just personal preference. In the sheet you shared mm/s (column e) is millimeters per second, correct? Yup! > [@FunnerSurfCraft](#): > > Regarding the z-offset, I did use the body of the laser, but I used the spoil board, not the top of the work surface. I will make this change. You did it correct (this is just for the calibration) when you actually setting up a job you use your spindle to set XYZ to the material and then switch to the laser > [@FunnerSurfCraft](#): > > Regarding II vs I power… how can I see/switch this setting? It’s a physical switch right on the front of the 45W laser. 15 watt doesn’t have it ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 4:35pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/5 "2026-02-16T16:35:25Z")
copy that. it’s been on II. just ran a few more tests calibrating from the top of the 6mm bb. no difference. can we jump on a call to trouble shoot? ---
**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\ **Post date:** [February 16, 2026, 6:33pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/6 "2026-02-16T18:33:00Z")
When you deploy your laser and manually go to Z zero does that 21mm block fit between your material and laser body like it should? ![image](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/0/0f4d41f4bdfceb7b72f15ec13dd57927aa53b12e.jpeg) ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 6:50pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/7 "2026-02-16T18:50:19Z")
yes, it does ---
**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\ **Post date:** [February 16, 2026, 6:55pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/8 "2026-02-16T18:55:03Z")
Ok, and if you’re on power level II (2) then we’re looking at a few things: Dirty lens… A lens that’s blocked by smoke or a lens that is dirty can seriously hinder performance. Are you running air assist? And is it strong enough to push smoke away? Have you checked your lens to see if it’s dirty? How are you creating your G code (what program) and can you post it here [![](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/9/9dc9ab381b70e1453d6e5e724bb1bd0c3d44dd8a.jpeg "How to Clean the Lens of Your Engraving Laser - Educational Series") ](https://www.youtube.com/watch?v=MLzFjfEJGa4) That’s obviously not your exact laser, but you can pull the nozzle off your laser and clean it. ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 7:09pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/9 "2026-02-16T19:09:54Z")
[Laser Cut 1.cnc](https://forum.avidcnc.com/uploads/short-url/vngCtYyZ2I4robWzBrfQEQJpHML.cnc) (1.1 MB) Thanks Eric, see my answers in bold. Ok, and if you’re on power level II (2) then we’re looking at a few things: _**The switch is as far right as it goes (towards II). Image attached. It that normal or is it getting blocked?**_ Dirty lens… A lens that’s blocked by smoke or a lens that is dirty can seriously hinder performance. _ **The laser is brand new** _ Are you running air assist? And is it strong enough to push smoke away? _ **Yes, lots of air flowing out the bottom of the laser, zero smoke visible** _ Have you checked your lens to see if it’s dirty? _ **The laser is brand new** _ How are you creating your G code (what program) and can you post it here _ **v-carve pro. attached** _ ![IMG_0290](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/0/01533f0b298304c3021ea3a080a9f6a43753ba86.jpeg) ![IMG_0291](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/2/22d5ba05fbde442079dd71438271da90b4db8fe1.jpeg) ---
**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\ **Post date:** [February 16, 2026, 7:30pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/10 "2026-02-16T19:30:44Z")
> [@FunnerSurfCraft](#): > > Ok, and if you’re on power level II (2) then we’re looking at a few things: > _**The switch is as far right as it goes (towards II). Image attached. It that normal or is it getting blocked?**_ I = half of the diodes on the laser are being used II = all of the diodes on the laser are being used (full power) > [@FunnerSurfCraft](#): > > Dirty lens… A lens that’s blocked by smoke or a lens that is dirty can seriously hinder performance. > _ **The laser is brand new** _ Soot can get on the lens in seconds especially if you don’t use the air assist > [@FunnerSurfCraft](#): > > Are you running air assist? And is it strong enough to push smoke away? > _ **Yes, lots of air flowing out the bottom of the laser, zero smoke visible** _ Smoke, even if there for a split second can obscure the laser light. You really need to make sure you’re properly mitigating it. And to be clear on air assist: There’s a fan that pushes air down, and there is also air from your air compressor that is controlled from a flow valve on the laser mount plate. The latter is what actually keeps the smoke away from your cut and the dirt off of the lens. > [@FunnerSurfCraft](#): > > How are you creating your G code (what program) and can you post it here > _ **v-carve pro. attached** _ I would need to see your G code to actually determine if there any problems, but from what I can see from your picture you are cutting at high power, but you are cutting way out of focus. The diameter of that laser beam is .007" and what I am seeing there looks to be .125", so that tells me that your laser is cutting really high, which is why you’re not seeing the cutting performance you expect. ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 7:45pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/11 "2026-02-16T19:45:38Z")
> [@Eric](#): > > The diameter of that laser beam is .007" and what I am seeing there looks to be .125", so that tells me that your laser is cutting really high, which is why you’re not seeing the cutting performance you expect. how do I set the beam to .007” ? ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 7:47pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/12 "2026-02-16T19:47:44Z")
> [@Eric](#): > > I would need to see your G code to actually determine if there any problems how do I send you the g-code? I previously attached what I upload to cnc12 ---
**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\ **Post date:** [February 16, 2026, 7:58pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/13 "2026-02-16T19:58:18Z")
Sorry, I missed your G code in that earlier post. Took a look and the G code is fine, you have your Z zero set right and your power level is 100% > [@FunnerSurfCraft](#): > > how do I set the beam to .007” ? The laser bean is cone shaped, that’s why getting the laser the correct height above the surface of the material is key (think of using a magnifying glass to focus like to make a fire) At it’s smallest the beam is .007" What I am seeing is that your beam width is a lot wider and that’s due to you either cutting too hight or too low. Triple check this: Go to UTILS, Diode Laser, Deploy Laser (laser will drop down) if you drive your machine over top of the material you’re intending to cut and move it down until your DRO reads Z zero does that 21mm block fit right under the laser BODY (NOT the nozzle) ![image](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/f/f4f8f2a9c9ba5d498e816b646c0e7307411f1709.jpeg) Just like this. If it does than your Z zero and your laser calibration is correct. Also check: when your laser deploys are you positive it’s coming all the way down on the deployment? If you push it downwards can it go any farther? Again, it looks like you’re cutting way to high here which is why you’re not seeing any cutting performance. Solving for that incorrect height is what we’re trying to do here. Either either a setup issue or a calibration issue. ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 8:59pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/14 "2026-02-16T20:59:20Z")
ok, I just did that… I set the z to zero, then ran the deploy command…. z automatically went up to 5.3417… then the laser deployed… same height above as before ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 8:25pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/16 "2026-02-16T20:25:31Z")
> [@Laser Feed and Speed Chart](https://forum.avidcnc.com/t/laser-feed-and-speed-chart/5374/17): > > Go to UTILS, Diode Laser, Deploy Laser (laser will drop down) > > if you drive your machine over top of the material you’re intending to cut and move it down until your DRO reads Z zero does that 21mm block fit right under the laser BODY (NOT the nozzle) ok, so I just did this, without any job uploaded, it’s about 6’’ above the worksurface after hitting deploy ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 8:26pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/17 "2026-02-16T20:26:45Z")
> [@Laser Feed and Speed Chart](https://forum.avidcnc.com/t/laser-feed-and-speed-chart/5374/17): > > Also check: when your laser deploys are you positive it’s coming all the way down on the deployment? If you push it downwards can it go any farther? this part seems right, after hitting deploy, it’s going as far down as it can go, full extension ---
**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\ **Post date:** [February 16, 2026, 8:31pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/18 "2026-02-16T20:31:10Z")
> [@FunnerSurfCraft](#): > > ok, so I just did this, without any job uploaded, it’s about 6’’ above the worksurface after hitting deploy if it’s that high sounds like you didn’t drive the Z axis down to your material, you need to jog down so your Z reads 0 ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 8:31pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/19 "2026-02-16T20:31:24Z")
pics for the last 2 comments… what’s next? height after deploy ![image](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/6/6585ef3637ef3ceb31e11c41edc2d420cb018f55.jpeg) fully extended ![IMG_0297](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/7/7536065efcda32e2363b1cc5cb53bfb0302c9edd.jpeg) ---
**Author:** ![FunnerSurfCraft](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@FunnerSurfCraft](https://forum.avidcnc.com/u/FunnerSurfCraft)\ **Post date:** [February 16, 2026, 8:37pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/20 "2026-02-16T20:37:10Z")
> [@Eric](#): > > if it’s that high sounds like you didn’t drive the Z axis down to your material, you need to jog down so your Z reads 0 ok, I just did that… I set the z to zero, then ran the deploy command…. z automatically went up to 5.3417… then the laser deployed… same height above as before ---
**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\ **Post date:** [February 16, 2026, 9:14pm UTC](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770/21 "2026-02-16T21:14:38Z")
Sorry I should have made this more clear: Do these exact steps: Go to the UTILs menu and to go to “switch to previous tool” Then take your touch plate and Z zero to the top of your material with your spindle tool Remove the touch plate and drive the bit down on top of your material. Confirm that the DRO reads Z zero Now go to UTILs and to laser utilities and then to “deploy laser” (laser will drop down) jog the laser over the material, then jog it down until your DRO reads 0. DO NOT reset any zeroing, just jog the laser as instructed. Does your 21MM block fit between the body of the laser and the material like this: ![image](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/f/f4f8f2a9c9ba5d498e816b646c0e7307411f1709.jpeg) [Next page](https://forum.avidcnc.com/t/45-watt-laser-not-burning-as-expected/5770.md?page=2)