Yea I thought of that and found 22mm dies on eBay, but for one one use it didn’t seem to make sense. Ended up going without the nozzle and use a magnetic held air line. Beam has no problem going from lens to workpiece 
Happy twosday everyone.
Still working on it but I’m close now.
Decided to go back and redo Mirror 1 to 2 and 2 to 3 and 3 to lens.
Pretty close now but have to get to something else first.
As a related question does anyone have any experience with either a pricey SPT type CO2 tube with the built in red dot or with beam combiners, do they really make the align process easier and or faster?
Thanks for your comments.
John
Good progress.
I don’t have a visual laser combined with the invisible cutting laser. Seemed like one more thing to keep aligned, so I’m not sure I’d use it for precise laser alignment.
However I do see one advantage when running a box over the cut pattern. I can’t see when a section of wood missed the cut pattern. Simple solution is to not be stingy about the amount of waste wood.
So I’d use it if I had it, but can’t justify adding it.
If i was trying to see where a point straight down from a overhang like a porch i would use a plumbob hanging from the center of one side (front) mark on tape where it lands, then from a side mark where it lands. With those two points you can make i “bullseye” . If when you test fire the burn don’t appear where you expect it you could figure out what direction the lense is off.
I have no ’ led pointer’ on my machine, removed it within a few weeks of dellivery…
Russ has a couple of videos, < 20 min each. Take a few and watch them…
Good luck…
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Hi John, can you try an ‘indent test’?
Scrap piece of wood, 3 layers of masking tape, place under nozzle, raise bed to leave a soft impression of nozzle tip.
Lower bed, remove nozzle without disturbing scrap, fire through lens.
Does burn align with the impression?
RESOLVED
To answer the question posed in the thread title - Yes, the nozzle was blocking the laser.
The re-calibration has returned the beam to the center of the nozzle.
I had just completed a full calibration the day before this problem and had not run the cutter very hard at all.
Slow cuts, no engraving, just testing the focus and trying some cuts to see how everything was working.
So, I have no idea how the tube/mirror/mount/whatever got out of alignment.
Obviously something was loose and I’d sure like to know what so I can keep a check on it.
Jack, was your led pointer the beam combiner type or the kind you hang off the laser head down tube? I’ve watched many of Russ’ videos and in his latest on beam combiners he seemed a bit more positive about them vs his early videos. I’ll rewatch today.
Tim, first thing I tried. As I said above, turns out the beam was off towards 12 o’clock about 1 mm and thus being blocked by the nozzle.
BTW, if you’re thinking well, the laser was scorching or etching and heating your nozzle, that should have been a clue. Nope. As I said in an earlier post I ran dozens of cut lines back and forth with the nozzle attached to see if I could get any heating or deformation of the nozzle and there was none. Check both visually and with a digital thermometer and there was nothing to see. I can only assume that since aluminium is such a good heat conductor that the heat was going up thru the nozzle then the alum tube and into the alum mirror mount.
Thanks again for all the comments, great forum!
John
Mine was that stock thing adding mass to the head assembly…
The problem is it’s pretty worthless for accurate use. You can’t possibly see the laser dot well enough to align something that misalignment couldn’t be seen by the eye.
Might be nice for general alignment. If I changed the focal length I had to re align the pointer.
Use a jig setup or a little extra material loss and I do fine without it.
I thought it would be nice to have one factory aligned at the factory with the tube. Anytime you put something in the beam path here is a loss. Beam combiners have a measurable loss.
Still haven’t decided if I wish to replace my tube with one that has the built in led. Don’t really know if I would find it worth while.
Assuming this is m3? I would have though it would have showed up in the ‘tape over the end of the tube’ test.
Keep in mind that your mirrors at a 45 deg angle, so the beam only sees, I guess the sin 45 degs * mirror size. There isn’t a lot of room for error.
Good luck
Jack
Russ’s video “RDWorks Learning Lab 222 Beam combiners A new approach” dated Dec 7, 2021 ends with “If it’s done properly a beam combiner can produce fantastic results.”
He’s using his adjustable Mirror 3 mount, now available from CloudRay, as well as a custom beam combiner which I guess you would have to fabricate. Although he says after initial setup he doesn’t touch the red dot laser.
He uses a combination of laser spots and red dot spots and sets the beam accurately.
Oh well, more tinkering to follow.
John
Thanks… I’m always behind his videos. He had over 150 when I started watching him. I’ll check it out, but the 99.9% of the time I’ve used mine, it’s sans led pointer. So really don’t know if I’d use it.
Nice thing about Russ, he’ll tell you when he goofs…
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