Laser Update

The Big laser works… It’s hotter and faster. But we still have problems.

We’re in murphy’s law territory here. Everything we discovered is unrelated to the initial optical overhaul. However, we think it is a given that these problems already existed, but were likely not recognized by members, and certainly not reported.

Z-stop failure – Traced to a board level opto-isolator problem.

Z-drive goes up, but not down – suspect controller though can’t prove.

X and Y axis skip steps and lose position – Acceleration parameter fixes this.

Our solution is to install the new MPC8530 controller in the big laser instead of the small laser. Another controller was purchased to fix the small laser with the last of the laser overhaul budget. (Done, same controller, same price, order confirmed Sunday.)

Bonus – Now we will have a matching set of controls and control software.

This is making everything slow going, but putting a glitchy machine into full rotation just results in passing our frustrations, wasted materials, and more catastrophic failures on to everyone else.

The new controller is scheduled to land in town on Wednesday before end of day. Lorin and I will start prepping for the install Wednesday.

We are looking for help to get this conversion done between Thursday and the weekend. We can use help getting a second laser computer set up in the annex with lasercut6.1 on it. Also looking for help installing the new control which will start Thursday afternoon.

There’s always more to a story, but it’s better in conversation.

See you at the meeting or huddled around the fablab.


surrogate writer and member of team frustration.

with many thanks to Brett and Lorin

I have a small pile of optoisolators sitting around if needed.
-Dave B.

The second MPC8530S control box arrived Thursday and has been delivered to HIVE13. It was intended to replace the big laser controller as we thought it was flaky.
However the Big Laser is currently running well and cut parts for the Loveland Bionic Tigers robotics team on Thursday.

The new controller currently resides in the gray cabinet in FABLAB. I recommend that it stay there until we get all the kinks ironed out of the one installed in the small laser.


Awesome! Thank you Dave and to everyone who has put in a ton of work to get the laser going good. Its good to hear that we have a robotic team using the hive and that we can help the community. I can’t wait to recover from this surgery and not have to worry about any tough surgeries for a while. I owe the hive a lot of time when I am on my feet again, the last 2 years have sucked!

Any updates on this?

Will was using the later last night and they were weird periods where the laser would stutter and loose cut. So something is still messed up.


Like weird periods with the x axis or y axis? Or not isolatable?

I’m coming in tonight to make some cuts. The small laser seemed to be working well last week, but I’m no further on understanding why the switches don’t work.

The large laser last night was experiencing some odd vibration when cutting straight lines. It was Semi-repeatable. I’m going to get the full report of what I was encountering to Lorin shortly.
The issue is likely related to some of the acceleration settings and because the material I was cutting was moving quickly at low power because I was specifically intending not to cut through the material. This is likely not present at slower speeds that are intended to cut through 1/4" acrylic, etc.

This is also a reminder that everyone will need to re-certify on the lasers. When I got re-certified, Dave wanted me to remind everyone that asked. He did say there was hopefully going to be a certification class coming soon for those not lucky enough to catch one of them when they were at the Hive and NOT BUSY working on the lasers.

Just curious, why do we need to get recertified?

I would say the main reason is the guys that are offering the time to maintain them say so. That’s the hard stop reason.

But there are several things which have changed with how the setups work. There are more things to check and confirm before you start the lasers and after you shut them down.

Brett - at least I’m guessing pipitoneb is Brett, what time will you be in tonight?

It was on both X and Y. Seemed to be after a curved cut, then straight, then bananas, then back to straight. Definitely some good lead in so I’m thinking it is some kind of setting.

Should have taken a pic.

We have pics and video.

I can’t be totally sure due to a stop I need to make in the way, but around 6:00.

Our rational for recertification was three things:
1. Changes that have driven new procedures
2. Preventing some of the problems, like head crashes, that have happened in the past
3. Some folks that were doing dangerous things, like leaving the laser running unattended overnight.

It should be quite easy for already certified folks.