When the beam points to the center of the mirror the reflection is not going down through the head tube center, so in order to make it pass through the tube end I need to align the mirror in a wrong way and make the beam to goes down forming a diagonal:
This is not desired.
Another solution is to move up the laser tube so the beam ends up hitting upper in the 3rd mirror.
Unfortunately, the head design reaches its limit in the circumference entry before the beam reaches the tube center
So. what can I do?
thanks
I read somewhere in this forum about an acrylic header model. I’d like to try it. Where can I find that design?
I changed the head on mine out with something I can adjust in the Z direction.
Once you setup your machines beam, you have to catch it with m3. It’s nice to have it centered on m3, but it’s more important to get it down the center of the tube… if not the resultant cut will be at an angle.
The head adjustment problem is one of the major issues in doing a good alignment with many of these machines, not only the K40… this is my original head… notice the center of the mirror is not aligned with the center of the hole…
There’s really no way, other than mechanical changes to the optical path will correctly fix this, besides an adjustable head. As the beam leaves m1, it has to be 3d square with the other mirrors/lens/table for the machine to operate correctly.
Raise/lower the tube, beam impact point will raise/lower the same amount on all mirrors.
Might have to pick the best of the options…
Usually these are not that far off or the manufacturer couldn’t adjust it … is this a new machine or ? I’m wondering if you really have it aligned properly or was something changed causing this?
If @jkwilborn can’t provide a source for the solution he showed might I suggest you modify your existing head some. First thing I would look at is if you can get your mirror held into that square adjustment block and flip it over so that the reflective mirror surface is not so far back from the 45 degree angled surface. This could get your far closer to a centered shot from mirror 2 into the mirror 3/head opening and some Z offset shims then get your beam through the center bore.
If that doesn’t work but your mirror is already pretty close to the back of that adjustment block, try adjusting it down so there is no gap between the lens holder and the 45 degree surface of the laser head. Now see if you can adjust Z so that you can get the beam straight down and through the cone center bore.
cool and yes, I’m well aware of Russ’ lightweight laser head. I did a run with SendCutSend on all the parts to build a couple and the vice/jaws to bend them. Just didn’t want to go through the whole process Russ did of replacing tube mount, all custom mirror mounts AND the laser head.
I will eventually get back to it and build a setup which puts a linear rail on the K40 X axis and mounts one of Russ’ lightweight heads but keeps the beam aligned with stock mounts and tube height.
