U Axis Stepper Motor Driver Installation

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On April 24 I completed the physical and electrical installation of an additional stepper motor driver in the laser. This type of device sits between the Ruida laser controller and the actual stepper motor that mechanically drives the various axes of the machinery. The new one adds support for the U axis, in addition to the existing X, Y, and Z axes.

The idea is that this will better support the use of rotary adapters with Lightburn software. This theory has yet to be proven.

Here is what the new Leadshine 3DM583 stepper motor driver look like on the inside. It’s more complex than I expected. It’s the current version of the 3ND583 driver that is used in the existing X and Y axes.

And here is a view of the electronics inside the laser, before the addition of the new driver. The off-white box on the left is the Ruida laser controller. The three black boxes in the middle are the existing stepper drivers, for the X, Y, and Z axes. The shiny perforated-metal box on the right edge is one of several power supplies. The new driver will be squeezed in above the Z axis driver.

The biggest challenge mechanically was creating this 16mm hole in the chassis to mount the connector for attaching either of our two rotary adapters to the new driver. This was a fine excuse to acquire a new tool, so I picked up a set of annular cutters. There’s just room to use one of these with a small battery-powered hand drill, and it did a fine job of making a hole in the heavy sheet steel of the laser chassis. To the left of the hole there’s a magnet, which I used to help keep the tiny chips of metal from going all over the place. The light green material is a metal cutting fluid called Anchorlube.

And here’s what the room looked like after an afternoon and evening of messing around. The electronics area is accessed through the doors on the right side, next to the orange wall. There isn’t a lot of extra room around the laser for service! Both of the rotary adapters can be seen on the laser’s bed. On the desk is a mix of tools that belong in the laser room, tools I brought from home, and tools I scrounged from other parts of Colab.

I performed only preliminary basic tests to confirm the installation. I’m able to rotate either rotary adapter using the U+ and U- buttons on the controller keypad, which proves that the electrical connections are basically working. However, it didn’t behave the way I expected. All the other axis motion buttons cause the corresponding motor to run while the button is held down. The new U axis, however, continues to move after the button is released, and only stops when another button is pressed. I expect there’s a setting for that, but I didn’t find it before quitting for the day.

Laser Classes Update

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Sessions of the Basic Operation and Safety class for the laser are continuing at an accelerated pace: 4 sessions in March, 6 in April. I’ll try to keep this up as long as there is demand.

For now we are going to try to stick to a schedule for scheduling new classes. Specifically, new classes will be added once per calendar month, sometime during the last week of the preceding month. Classes might still be added or changed at any time, but most new classes will be posted in a single batch during the last week of the month before they occur. The purpose of this schedule is to limit the number of volunteer hours needed just to maintain the schedule.

I’ve always preferred that the BOS classes be free, because they’re essential to the use of the laser and we do want people to use the laser. However, we’ve found that the number of people who sign up for the free class and then fail to show up is unacceptably high, given the high demand for the BOS class. So for the moment we’re charging a nominal fee of $10 per student, in the hope that this will discourage people from skipping out on a class reservation. If this doesn’t work, we’ll have to resort to drastic measures, like making people pinky-swear that they will show up for class.

Rotary Adapter Workshop

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On April 12 we had a scheduled workshop session in the laser room with the goal of setting up and calibrating the two rotary adapters for use with the laser in its “new” configuration, and creating a set of simple procedures for laser users to follow in order to use one of the rotary adapters. I was joined by Kip, Guy, Renee, and Sriram, who were all very helpful in trying to figure things out.

A rotary adapter replaces the Y-axis motion of the gantry with rotary motion of the work piece, enabling the laser to work on a cylindrical or conical object. This has always meant unplugging the gantry and plugging in the rotary adapter in the same place. That’s what the original laser controller expected, and it worked fine. Enabling the rotary adapter with the old software just meant a different setting for calibrating the Y axis.

As best we could figure out at the workshop, this doesn’t work as expected with the new controller. If we enable the rotary adapter, the job can’t be started by pressing the Start button, as is our standard procedure. If we instead used the Send button and then started the job from the laser’s control panel, the job would try to run, but there would be no motion on the rotary axis. This despite the fact that jogging the position manually in the Y axis did correctly cause the rotary adapter to spin. We only figured out that much by reading forum posts online.

We were able to get a rotary job to run with both axes, but only by turning off the switch in Lightburn that enables the rotary adapter. So, as far as Lightburn and the Ruida controller were concerned, it was just running a normal flat job on the bed. Of course, the Y axis calibration was used instead of any rotary axis calibration. If we wanted to use this as the standard procedure for rotary jobs, we’d have to ask the user to change the calibration setting, and then remember to change it back after the rotary job is completed. This seems inconvenient and error-prone, and risks exposing a beginner laser user to extra complexity needed only by users of the rotary adapter. This would probably be unacceptable, especially given that we’ve gotten by this long without the rotary adapters being commonly used.

Our best guess is that we need to connect the rotary adapter to the Ruida controller’s “U” axis, which is currently unconnected. In order to do that, we’ll need to install a fourth stepper motor controller (in addition to the existing X, Y, and Z axis controllers). I have that stepper motor controller on order.

It’s also possible that there are controller settings and/or Lightburn software settings that need to be adjusted in order to make it work with the old method (unplugging the gantry and plugging the rotary adapter into the Y axis controller). If so, I’d think we would have learned about those settings from the forum threads we read, but we did not.

The five of us will get together for a followup workshop once the new controller has arrived.

Progress on Camera Installation

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Work is underway to add a camera to our laser. The camera will be installed on the underside of the laser’s lid, looking down onto the bed. After you’ve placed your material on the work bed of the laser, you’ll click the camera icon. This will take a snapshot of the bed with the material placed, and make that snapshot the background in the drawing area of the Lightburn software. It will then be easy to draw your design right on the image of your material, without having to fiddle around with aligning your material with your drawing. This has proven to be a nice convenience on newer model lasers that come equipped with a camera, so we can expect it to be helpful when added to our laser, which is now almost twelve years old.

For this to work well, the camera has to be in the exact same 3-dimensional position every time it’s used as when it was installed and calibrated. Our laser’s lid wasn’t originally designed with this requirement in mind, so I’ve made some modifications. Our laser already has an upgraded hinge, because the original hinges kept breaking. I replaced the four tiny cast aluminum (!) hinges with a beefy steel piano hinge running the full width of the lid. This hinge has very little mechanical play, so the camera’s X axis is well defined, as is the distance from the hinge pin to the camera. That just leaves the angle of tilt of the lid when it’s open.

The lid has pneumatic lifters, one on each side. These make it much easier to lift the heavy lid, and they keep the lid up after you’ve lifted it. However, the lifters get tired over months and years of use, and the open angle of the lid begins to droop. My idea for coping with this problem is to add cables, one on each side of the lid, that constrain exactly how high the lid can be opened. The pneumatic lifters will push against the cables to reach the same maximum height every time.

The cables are made out of eighth-inch stainless steel wire rope, with standard hardware, including a turnbuckle to allow each cable to be adjusted in length. Because the wire rope has sharp ends in multiple places, I’ve encased the wire rope and most of its hardware in a protective plastic sheath. A carabiner at each cable end then clips to a screw eye installed in the lid or chassis. Here’s what that looks like today:

Camera installation and calibration will be the next step.

Laser Classes Update

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We’ve held 15 sessions of the Laser Basic Operations and Safety class over the last six months. These classes were announced only to people already on the waiting list, and they filled up rapidly. We will continue to hold classes at a similar accelerated pace as long as they continue to fill up.

Go to the class signup page on the Colab web site here and check for class availability. If you don’t see any classes available and want to attend a class anytime soon, I recommend you sign up for the waiting list. We will continue to notify people on the waiting list by email before we open the classes for everybody.

If you took the laser class before we moved to the current Colab location on Mission Gorge Place, you learned to use the Full Spectrum Laser with its original Retina Engrave 3D electronics and software. Since then, we have upgraded to a Ruida laser controller and LightBurn software, and operation of this new configuration is somewhat different. You’re free to sign up for the updated basic class, in which you will learn the differences and refresh your memory of everything else, including safety rules. Or, you can wait for us to put together a shorter refresher course that concentrates on just the differences.

CoLab Student Project: Aquaponics, but Fish-Proof

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This is the first in a series of posts about how we’re using the newly commissioned 180W laser at CoLab! Follow along as we chronicle our creative and artistic adventures!

I’ve been trying out different aquaculture designs for a few years now, with some success. But the fish keep digging up the plants, and the turtles keep eating their leaves…so I’m sending the plants to plant jail!

I needed to cut some holes in acrylic sheet for the project, and selected this process because there’s almost no risk of chipping or cracking. It worked really well! This design should keep fish away from roots, and turtles away from foliage…hopefully…

Laser Classes now on sdcolab.org

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Classes for the laser are now being scheduled on the sdcolab.org web site.

We have scheduled, and already filled up, six classes between September 16 and September 25. More classes are due to be scheduled on an ongoing basis after that. Visit that web site to sign up or be added to the waiting list.

I hope you’re as excited as I am to see regular laser classes and routine laser use begin again!

Laser Classes to Resume!

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Hello Colaser community! It has been awhile (since things shut down for Covid, and then we moved the laser (twice!) and converted it to use completely different electronics and software. Now we are finally ready to resume training classes and normal appointments to use the laser. I will be announcing new classes within the next day or two, to start holding classes as soon as next week. If you want to take the whole class again from the beginning, please email class@colaser.org and I will add you to the list to receive email notification about new classes scheduled. If you would prefer to take an abbreviated class intended for people already experienced on our old laser configuration, please email class@colaser.org and let me know your preference. Note that I don’t have the abbreviated class prepared yet, so there may be a longer wait for the shorter class.

Laser Update

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The laser seems to be working fine after its long holiday.

I’ve updated the Lightburn software on the laptop. We now have two versions of Lightburn installed: the latest and greatest from the stable 1.7.x series, and a release candidate version from the 2.0.0RC series. You can run either one you like, but make sure only one is running at a time. I recommend going straight to the 2.0.0RC version, even though it’s not officially released. It’s the future, and so far it seems well-behaved. If you run into any problems with 2.0, you can always fall back to the 1.7 version installed.

As of yesterday, you no longer need to worry about turning on the ventilation fan or the air assist compressor. The ventilation fan will automatically come on when you power up the laser, and remain on until you switch it off. The air assist compressor will automatically come on when the laser starts to run your job, and automatically switch off at the end of the job. Please listen for and be aware of both fans, though, in case the automation somehow fails. It’s still your responsibility to make sure both are enabled while you’re running a job.

I also have a plan to install a two-speed capability on the air assist. This will be controlled by the Air setting for each layer (color) in your Lightburn job. If Air is on, the air assist will run at full speed, as it always has. If Air is off, the air assist will run at a minimal speed, just enough to keep smoke and ash out of the lens cone. You’re free to experiment to see which setting works best for your job. As a rule of thumb, you’ll probably want full speed for cutting, and low speed for engraving.

You still have to turn on the water chiller manually before operating the laser. If the water chiller isn’t circulating water, or if the laser’s lid isn’t down, the machine will go through the motions of running your job, but it will not fire the laser tube.

I’m in the final stages of revising the training for the new laser setup. I hope to be scheduling new classes by mid-July. If you’ve ever written to class@colaser.org about a class, I’ll email you when classes are available to schedule. If you haven’t, or if your email address has changed, you can write to class@colaser.org to get on the list.

If you want to get a jump on the training, look online for Lightburn tutorials. I’d suggest starting with YouTube videos. Or, if you’re more a reader of manuals, the official Lightburn documentation is pretty good. Lightburn supports several different laser types; where there’s a fork in the road, choose the one for CO2 lasers of the “DSP” type, with a Ruida controller. You’ll find a lot more information online than I can possible include in the training course.