DSP panel 'square' cut possible issue?

[Azirithdorr]

Hi all,

I think I've got my first k40 setup now - I've done my mirror alignments and such and have my focal point figured out ( I think ) using the AA head and a 63.5mm focal lens ( yeah, I need to get a shorter one for most of my work ). I also have the LO Z table installed.

The question I have for all you who are much more experienced than I is this: when I choose to draw a square from the DSP panel menu, I'm noticing the area of the square cut near the origin ( the upper left ) is a much finer and weaker cut then, say, the upper right or lower right - it isn't cutting the same throughout the square. I'm assuming that isn't normal and an indication that the machine isn't quite setup right yet - would that be due to any mirror alignments or could it possibly be my Z table isn't running level ? I did adjust all four of my brass nuts on the Z table to equalize them during installation, but maybe not good enough.

So, may I ask what you suggest I start checking ?

Thanks very much for reading and any suggestions :>

[Tech_Marco]

I think you better post a picture from the actual cut so that we can see it and comment it. In most case, it is an issue of alignment.

Marco

[Azirithdorr]

I think I'm getting it pinned down slowly with micro-adjustments to the mirrors. I was going to post a little video to show people for future reference, but it doesn't seem to want to load - just keeps saying loading for an hour ( it's 10 MB's though ).

[Tech_Marco]

You can't upload video direct. You should do YouTube or a download link from a remote server. Our Web service has limited-time space and bandwidth

Marco

[Azirithdorr]

10-4 - I've never done a Youtube vidoe, so let's see what happens

https://www.youtube.com/watch?v=gTl9hNz1tcA

[Azirithdorr]

I'm still running into issues - now though it's even at least: as the laser moves right, no matter where it is on the Y axis, the cutting power hitting the work material is getting weaker - For instance, it'll cut right through heavy cardstock on the left side up to almost the middle as you go right, but the whole right side ( say, in this example, making a template for my front panel, for example ) won't cut through - it'll 'score' it, but not cut through.

I checked the Z table for level against the gantry and it seems good all around, so I'm guessing my beam isn't hitting the focus lens evenly throughout my square - that it's, perhaps, going off-center and therefore not focusing correctly as the X axis moves to the right.

Althought I must need to keep adjusting, here's a question: would you say that getting the mirrors set would be 'easier' with a set of your upgraded mirror holders, as opposed to the rather questionable one's that come with the K40 to begin with? I also noticed that the brackets holding the mirror holders themselves were loose on the machine when I got it, so I'm guessing I might have to fine-tune where they are 'suppose' to be when I tighten them up too.

Five hours of adjusting and no real headway - adjusting mirror 1 to make the laser hit mirror two dead-on at home, great. I love X or Y and it goes off-center. I adjust to compensate for that on mirror 1, then it's completely off at home. doh.

Also, out of curiousity, this is at 40 power ( 37 corners ) at speed 60 with the 63.5mm focal lens - with your guy's experience, does that seem like it's exhibiting enough power if it's barely cutting through cardstock at those settings, or am I just having an overall power issue?

[Techgraphix]

The laserbeam does diverge a bit, a matter of millirads, but a wider beam gives you a smaller dot, that is lensoptics.. So i don't think this is the issue here.
Normaly i can align my laserbeam in about 5-10 minutes.
the alignment of the tube itself (both horizontal and vertical) can be a bit frustrating as you have to figure that out bij trial and error is my experience.
But aligning the mirrors is a "piece of cake":
take a few rounds of aluminiumfoil in the size of your mirrors (so your mirrors won't contaminate during the alignment) and stick them on the back of a few paper label-stickers.
Place these over the mirrors and (depending on the type of your head) over the entrance of your head.
By rubbing over the stickers you can see the contours of the mirrors and mark the middle.
The first mirror ( just in front of the tube) must be hit in the middle. If not, change the tubes alignment by lowering or raising it, move it left or right..
Use so much power that the dot is just visable. Try 5%, 10% till the tube starts.
If that is done, remove the sticker from the first mirror, move the bridge with the second (covered) mirror as close as possible to the first mirror and fire.
The dot should be somewhere in the middle. Now move the bridge as far as possible from the first mirror and fire again. If the second dot is at the same place, your first mirror is aligned.
Place the bridge somewhere in the middle, remove the sticker from the second mirror and move the head as close as possible to the second mirror and fire.
The dot should be somewhere in the middle. Now move the head as far as possible from the mirror and fire again.
If the second dot is not at the same spot, you need to adjust the second mirror till it is..
Now the tricky one.
As the beam needs to exit the head at the centre. raise the table just under the exit. place a paper under it and fire. There must be a small dot burnt in the paper. See if this dot is in the middle of the exit in both directions.
Now lower the table to the bottom an fire again. The marking should be much wider but at the same place.
You can also remove the lens and nozzle first to have a better marking.
Things that can go wrong here is that the beam will hit the nozzle and only a part of your power will exit. When you place the nozzle but not the lens you should see a round marking. If it looks like a half moon, most likely your head is not perpendicular.
This all doesn't need 5 hours to adjust.. even if you redo this all after the first alignment. Make sure you have enough stickers prepared

Kees

[Azirithdorr]

Thanks Kees, I'll keep at it. To be honest, I haven't adjusted the actual laser tube yet ( didn't even know it was adjustable :> ), so that's likely giving me some issues right from the start.

[Techgraphix]

I don't know how your lasertube is fixed in the machine. But usualy there are some screws to adjust the tube.. If not, make something...

Kees

[Azirithdorr]

I don't know how your lasertube is fixed in the machine. But usualy there are some screws to adjust the tube.. If not, make something...

Kees

It's nothing techy - just two half-circle clamp-like things, hinged on one side, with a long bolt on the other to clamp them down. Then, it's just a rubberish sheet of material between the clamps and the tube. I'll be able to rig something for sure, yeah. Probably just loosening off the clamps and 'wedging' up areas with paper or cardstock or some such will be enough.