Changed lens but lacking power/focus foxalien 40W

Community Laser Talk
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Hi all,
I use a 40w foxalien module, on a Masuter Pro chassis. Controlled via a laptop running Lightburn.
I had been succesfully cutting 5.5mm plywood to create boxes.

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I must have got 120 of these made before changing the lens. I should have had air assist but felt I was geting away with not having it, until 3 passes had stopped cutting through my ply boards, I changed the lens.hoping this might fix it, but if anything the cut is weaker than before.
I have checked my $30=1000 and $31=0
I used the 40mm aluminium spacer that comes with the laser module to set my height from the top of the board to the bottom of the module.
I have taken the module out and given all of the surfaces and the fins of the heat sink a clean.
Is there something that I haven’t tried, which might get me back to cutting ?
Thanks
Graham
Cheshire, UK

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Maybe some pictures of laser and lens etc. Cleaning/changing lens should have taken care of the problem.
Also look at pattern on the wall.
Guide to mechanical adjustments and maintenance

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Graham…
Looking at the picture odf the cut…your Focal length may be wrong..
Noticing the ‘cut lines’ are wide not a nice tight line…

Do a focal length ramp test to determine the best height off the material
to cut at… ( as I am sure you have done before)

When I,change lens, I always need to adjust even if it is the same type..
no two are exact… close maybe …

ps like the case design
Chuck

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Thank you Chuck.
I wasn’t familiar with ramp tests. I don’t know how I missed that particular memo, but anyway.
I did a ramp test and made a minor adjustment. Its better but still not quite there, so I will perform the same test tomorrow.
I didn’t remove the enclosure/extraction hood that i have over the machine. This makes it fiddly to get the calipers in for accurate measurement. I will be a bit more thorough tomorrow.
To give it ‘belt and braces’ so to speak, I have ordered an air pump to finally add air assist.
Graham

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The case design is for something I use for wall display. I work with plants and make things like this. Its experimental.

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Thats interesting. If the ramp test and height adjustment doesn’t fix the issue, this will be my next port of call. Thanks.

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Long shot but did you put the lens in correctly :slight_smile: grin
Assuming it was a drop in type… flat side down…

There are different thoughts on flat side up, but I’ve tried both and the
best for cutting in my applications is flat side down ..

and of course… clean :slight_smile:

and also beam alignment, via mirrors …

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With the foxalien module, I can only chabge the very outer lens. That comes in a brass housing.
So you simply unscrew the old one and screw the new one in place.
Perhaps I can buy just the lens and keep the brass housing next time.
In fact, as I look at this outer lens, or look through it it doesn’t seem to bend/refract light nuch, if any. Perhaps the focus of the beam happens higher up inside the laser module and this ‘lens’ is more of an end cap.
Or maybe the tolerances are so small that wgat looks to my eyes as a plain piece of glass, is actually doing just enough to the laser to focus it.

Anyway, short answer is that you can’t screw the lens on a fox alien module the wring way. Even I can’t get that wrong pal.

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Excellent… love the fool proof stuff…

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It’s more protective than an actual lens. I just clean mine with alcohol unless it becomes damaged. I use air assist on everything I do. Less for engraving and more for cuts. Keeps smoke from backing up into the lens.