Although the hv area is on the opposite side within the lps… I use a ceramic screwdriver for my own comfort… You can find these at Amazon…
I still have 7 of them around here…
Anytime you change machines/tubes/lps, you will probably have to modify your sources to some extent… just like a new batch of natural wood should be checked… all of these materials and tubes varies to some extent…
Unless you are way off, the effect should be minimal… and as @ednisley can attest, the output is relatively linear, so maximum output isn’t necessarily at 100% current…
This should be done at the factory, but it never is, at least with the Chinese machines I’ve dealt with…
Pretty much, I used 21mA on my previous tube, so I set it to 10.5mA…
Doing this adjustment ensures you cannot over drive your tube as you limit the maximum current the lps will deliver.
There are two things that come to mind. One is the natural lag when cutting thicker material. it tends to cut a cone shape with the top being larger in diameter than the bottom.
The other is that if your 3rd mirror is twisted slightly the beam will not be perfectly vertical but skewed a bit.that could cause it.
On a 80 watt co2 the bed is large and you can expect that the alignment will not be perfect on all areas of the bed. If the laser is not perfectly round when it goes through the lens then the cut will not be perfect. On some lasers they put a piece of acrylic infront of the final mirror and pulse the laser long enough to get a mark on the acrylic. Ideally the mark should be a even round engraving. If there are problems with the mirrors, dust damage alignment, that will affect the cutting. You can also do that trick on the first mirror, but don’t let the tube get soot. Also if you put a piece of tape on the end of the laser head cone and you get a non round mark from the pulse, then it is alignment issue, maybe just the last mirror is hitting the cone. If the oval shape of the cut is always aligned in one direction, that also points to the laser beam not being perfectly round. You can try lowering the table like 1/2 inch and pulsing on to a piece of acrylic to see if the beam is round.
Hope this helps. Cheers Marty
If we are talking about a few tenths of a millimeter, that may be true, but 0.2-0.3 mm has no influence. The machine bed must be level over the entire area, mine is anyway.
To check the correct 90 degree angle of the nozzle to the machine bed, on the X and Y side, you can either use the tool from Russ Sadler, (@jkwilborn showed it in a post here), or as I do it, I run the machine bed to max +Z, fires a short pulse. The result is a brown, round mark. Then, without moving my test shot #1, I move Z to my correct focus and shoot again. The result should preferably be a small hole or black dot, in the middle of the brown mark from shot 1, if not then adjustments must be made.
I don’t word it this way since the space station has cnc machine and they are not level… Gravity is a convenient tool or jig… Without that, more of a challenge to square this stuff up in 3d with normal tools…
Probably best stated as square in all three dimensions…
I’d like to point out this wasn’t very functional approach with my machine… The main issue is the screws were not straight, so the bed wobbled around the axes.
