Folks,
Tried to set the focus on the laser and observed the Z axis drop about 1/2"
immediately without the inching-up it normally does first. I tried a few
times with same results. Haley suspects bad limit switch on the plunger
mechanism and requested I send this message, as she doesn’t know if we have
replacements or if anyone else is already planning to address.
Thanks!
Matt
Thank you for reporting this issue.
There were several other related reports of the same issue recently - which I just went through to close/resolve, so we don’t have multiple threads for the same issue. I’ll leave this thread open until it’s resolved (again).
This has been a recurring issue as a result of a poorly designed auto focus plunger, combined with less than careful use of the laser. For now, please “manually focus” the laser. Keep in mind that even the manufacturer suggests that it’s best to use the manual focus method.
Feel free to continue to report when the plunger fails, so we can do our best to ‘fix’ it when it recurs (and it will…).
See related post on how to manually focus the laser here:
Thanks!
Lisa
Laser Committee Vice-Chairperson
The subject of manually focusing the laser came up a few months ago. As I recall, our illustrious leaders said that the focusing ruler doesn’t work, for one reason or another. That, and we have a different focal-length lens on the machine, now.
You just need the correct ruler for it. The lense currently on there is our standard one. It should be pretty easy for us to adjust.
I brought up idea of manual focusing a while back and it fizzled. Do we have a manual focus ruler?
It seems like we should be able to make our own ruler for whatever focal length the current lens requires.
Manual focusing wasn’t covered in the laser training I attended.
I didn’t even learn about manual focusing until I downloaded the manual from Full Spectrum and read through it…the laser chairperson William Petefish commented that I had downloaded the wrong manual but when I asked which part of it was wrong he never replied, so manual focusing to me is still up in the air.
The manual Lisa noted above is the one that William said was the wrong manual.
We have the same laser here at Perot. I will create a drawing of the ruler and upload it here this morning if we need to make one.
pat
Is anyone doing maintenance on the Laser Cutter? I don’t get to DMS often but it seems every time I’m there (including early mornings) it seems the Laser Cutter is in use. Is this typical operation of a laser cutter of this design? Is it being stressed to its design limit?
There are volunteers on the Laser Committee doing maintenance, but they could always use more help.
Hi Pat (@Captchemo) …
That would be awesome! I was going to try to wing it if they didn’t send the file; but it would be so much easier to start with known accurate dimensions…
Thanks so much!
Lisa
Hi Paul (@paulstaf),
As far as I know, the link I included is the correct manual. Perhaps William (@william_petefish) didn’t notice your request for clarification? (I know I miss a lot when there is a lot of new activity on the forums… It’s bound to happen.)
At any rate, I do know the info on page 30 is correct.
I imagine manual focusing gets overlooked in training because our focus ruler got lost. 
Once we get an accurate copy made, I’ll be sure the copy of the file to cut out more is uploaded to the wiki so we can make more as needed.
No need for auto focus to be up in the air for you or anyone else. It’s allowed, and as far as I’m concerned anyone using the laser should be able to do it.
Thanks!
Lisa
Laser Committee Vice-Chairperson
Hello all… It’s hard for me to track the conversations. So is laser working or down? Best I can tell from conversation is we need to get focus ruler made to be able to manually focus. I have a pen to engrave tonight, if it’s working.
Hi Manny (@munawar)…
As of last night, it was working fine. The auto-focus was working at the moment. I just received a file from Full Spectrum to use to cut a new Focus Ruler. I can’t attach it on this post. I’ll try forwarding the e-mail; and, if that doesn’t work, I’ll upload it to the wiki and post a link during my lunch in a couple/few hours. 
Linked is the file (converted from XPS to PDF in order to upload it) that
was sent to us by Full Spectrum to use to cut a new 2" Focus Ruler for our
Full Spectrum Pro LF Series 36x24 CO2 Laser cutter / engraver. Please try
it and let me know if it works:
I’ve dealt with multiple FS laser units in the past, and I can say from experience that the focus ruler needs to be created based on measurements from the specific laser it’s going to be used on. Between two different (same model) machines, there was a 6mm difference.
My method for measuring the focal length was to put a thick piece of acrylic on the bed set up on an angle so that one end was higher than the other. Then I cut a series of lines using a low enough power that even at proper focus won’t cut all the way through. Once the cuts were done, I measured the height with the depth gauge on a pair of callipers for the best (deepest) cut and used that.
Thanks for the tips, Sean (@zootboy)!
If you happen to be at the 'Space and have time, it would be most awesome if you could whip a ruler or two out using the method you describe!
I can definitely do that on Saturday, assuming there’s some scrap stock lying around that’s thick enough.
I’ll make a ruler tonight. BTW I also have some hardware to re-enforce the
current focuser.
Also, the lens is a 2.5" not a 2".