I usually never post at forums but I’m stuck and would appreciate some help.
My k40 had many issues but I’m stuck at mirror #2 alignment.
If I move the horizontal (x) axis the beam moves in weird curve that I can’t fix.
I think already had it pretty well aligned once but decided to redo it because the beam on first mirror wasn’t very centered (probably didn’t even matter but it bugged me). Now I can’t get it to align again.
I many days since the 23rd trying to fix stuff on my k40-variant inx
Interesting to read about, but I think the white hollow circle is just the effect of using thermal paper. it goes from black to white again in the enter.
Anyway idea on the mirror alignment leading to this problem and can’t fix the the two screws I’m supposed to move?
The tube resonating in TEM₀₁* (“donut mode”) that @jkwilborn has suggested would definitely result in much worse performance and is the typical first stage of a tube that is degrading. But it wouldn’t explain “weird curves.” I don’t think that you say whether you are getting those from a single test fire or from multiple test fires with your witness paper in the same spot.
If it’s from a single test fire, I’d look for a loose mirror vibrating from, say, fan-induced vibrations.
If it’s from multiple test fires without moving the witness paper, I’d look for a loose eccentric wheel on the carriage, or something else loose on the gantry.
If the tube has shifted modes, you will get lower effective power and can expect it to keep shifting worse. If you end up replacing your tube, of course you will have to redo alignment, but if the problem is in your carriage, you can probably diagnose and fix that even if the tube happens to be in “donut mode”.
Not being able to edit posts is because spammers kept making innocuous posts and editing them substantially later to add spam links, so we had to disable post editing for users new to the forums. Spammers are why we can’t have nice things.
After you stick around and interact on the forum for a while, you’ll get an automated message from the system about being “promoted” to a new “trust level” and you’ll be able to edit posts.
the dots are from moving the carriage once along horizontal (x) axis (manually, stop and fire). Didn’t mention this you are right.
The carriage doesn’t feel lose.
I wonder if it has something to that I moved the mirror 2 platfrom in both axis (not on the kinematic mount the other adjustment screws. It was needed to bring the mirror into the beam path after I made changed to mirror 1 mount. mirror 2 base mount might not be perfectly perpendicular to the x rail, but the mirror adjustments should be able to compensate for that. Thats what they are for I guess. As long as the rail is straight.
I’m still not certain I understand — is each dot a separate firing, or are some or all of the dots the result of multiple firings?
What about the Y gantry carriage? Or the mirror #2 platform? Are any mirrors loose in their holders?
Are you aware of reverse laser alignment tools?
I don’t know where you are geographically. I bought an American Photonics reverse visible red laser alignment tool. I can’t tell the difference between these two listings:
With these, you point them backwards from the nozzle tube (without a lens in place) and work backwards from mirror #3 and don’t have to burn anything except to align the tube to mirror #1.
Yeah but if you follow the other link the default size is for the K40, and I can’t tell how the default K40 size of the first link is different from the second with K40 in the title…
I would look at the X carriage being bent if that happens when moving from left to right on the X carriage. Test by getting a straight edge you can put under the X axis making sure the left and right edges are the same distance below the X axis(on the ends) and then measure up to the X carriage across the length of the X axis.
Each string of dots is the result of firing at different points along the x axis (moving manually, then firing, the moving it quarter of the way more or so).
There are multiple different strings of dots because I made adjustments to the 2. mirror, but I can’t get rid of this error.
They Y-positon didn’t change for all of this.
Regarding straightness, I roughly adjusted the x axis to have an even distance to the bed (the bed is all over the place, not even ±2mm, I will probably replace it with a height adjustable honeycomb bed later)
I’m from germany. I’ve heared about these alignment tools, but I was hoping I could do without.
so then you can not use the bed to tell if the X axis rail is straight or bent. You need to find another way to make sure your X axis rail is not bent. Try a ‘straight edge’ tool across the top of the rail. Remove the X axis rail if you have to.
