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Configuring a Ruida Controller

Info

A factory reset of a Ruida controller resets it to the stock configuration supplied by Ruida, not the configuration your laser's manufacturer applied to it. Because of this, a factory reset is not recommended. If you've already done it, this guide is here to help.

When you purchase a laser with a DSP controller installed, the manufacturer configures the laser controller to match the machine configuration.

This guide is here to help you if you need to do this configuration yourself, either because you are installing a new controller into a machine or because you did a factory reset of your controller.

Ruida Machine Settings in LightBurn

Tip

It's a good idea to use the Save to File button to back up your settings before making changes, so you can revert to what you had before if needed.

With the laser/controller connected to your computer and powered on, go to Edit → Machine Settings to open the Machine Settings window. LightBurn will automatically read the settings from the controller when this window is opened.

As you're making changes, the Read button will tell LightBurn to read the configuration from the controller, and Write will save the settings in LightBurn back to the controller. For more information on the Machine Settings window, see our page on Machine Settings.

The top section of the list is referred to as user settings – these are settings that are intended to be tunable by the user if necessary. The lower section, under Vendor Settings, are things usually configured for you by the factory and should only be changed if you have a good reason for doing so.

Click to expand the Vendor Settings section, and, after acknowledging the warning, you'll see the below settings.

The first section is general configuration, and then there are settings that are specific to each axis, followed by a Laser Settings section, for configuration specific to the laser type.

Homing, Directions, and Travel

A DSP laser will have homing switches – one on each axis. They might be physical lever-type micro switches, optical beam-break switches, or inductive proximity sensors. Locate the switch at the end of the X axis, and the one for the Y axis. Note that a Ruida controller homes using the X- and Y- limit switches.

When you power up the laser, the first thing it will do is move toward the corner it thinks those switches are at to home itself. If it's moving in in the wrong direction, you'll have to hit the ESC button on the controller itself to stop it.

To fix this, you'll need to go to the X Axis Settings and Y Axis Settings under Vendor Settings. Near the top of each will be three check boxes:

  • Invert Keypad Direction: Controls which way the arrow buttons move the laser.
  • Limiter Polarity: Tells the controller whether the limit switch triggers high (normally open) or low (normally closed) when contacted.
  • Direction Polarity: Controls which way the motor moves in general.

Step 1: Correct direction of travel

Before continuing onto other steps, make sure that the X axis and Y axis move properly when you power on the machine.

There are only 4 possible combinations of Limiter Polarity and Direction Polarity for each axis. Without access to your machine, we can't tell you the correct combination, but change those settings for the X axis until it moves properly and recognizes the homing switch when you power up the machine. Once the X axis is correct, do the same for the Y axis.

Step 2: Correct keypad controls

When the limiter and direction settings are correct, check that the keypad arrows on the machine are moving the laser in the correct direction. If not, toggle the Invert Keypad Direction button for whichever axis is wrong.

Step 3: Set Max travel

You will also need to set the Max Travel value for the X and Y Axes - these values dictate the length of each axis, and together define the size of the work area of the machine.

Step Length Calibration

The next part is figuring out how far the laser moves when you tell it to, and how far off it is. The controller needs to know how far a single step moves when it sends a step pulse to the motors so it can translate real measurements into the proper number of steps.

Rough Calibration

You'll need to start by doing rough adjustments to get close enough to the correct values to be able to calibrate the step length properly.

In LightBurn, set the Start From setting in the Laser Window to Absolute Coords. See Coordinates and Job Origin for help.

Draw a small rectangle at the origin. Start with 10 x 10 or 20 x 20 mm, like this:

Tip

Note that your origin corner might be in a different spot than shown here. You should set it in Device Settings to match the origin corner of the machine.

Now, use the Frame button and compare the size of the frame to the size of the rectangle.

  • If the laser is barely moving, your step size is too big – the controller thinks it's moving more than it actually is.
  • If the framing is much too large, the step size is too small – the controller thinks it needs to take more steps than are actually necessary.

Adjust the X Axis and Y Axis settings for Step Length based on what you saw with the framing. The changes are proportional to the difference between the size of the rectangle and the amount of travel:

  • If the laser moved twice as far as it should, double the step length value.
  • If the laser only moved half as far as it should, cut the step length in half.

Frame again and repeat the adjustment process until the size of the framing is reasonably close to the size of the rectangle you drew.

Final Calibration

Draw a box similar to the first box, but make it larger – 100 mm or 200 mm is generally a good size to work with. The larger box makes it easier to get precise enough measurements without specialized equipment.

Set the Min Power and Max Power values low, but high enough to make a mark. Run the job to engrave the rectangle on a piece of scrap material. Measure the result as accurately as you can.

This time, you'll need to do just a of math to calculate the with the step size:

  • New Step Size = (Current Step Size * Measured Length) / Requested Length

As you are dialing in the above settings, if the steppers skip or make buzzing sounds, you might need to reduce the Idle Acceleration or Idle Speed settings near the top. Those things will require tuning with some trial and error.

Fixing Skewed Engraving

An occasional problem with new setups, and sometimes even existing machines, is lines cutting correctly, but engravings coming out slanted or skewed, like this:

If your output looks like this, you likely have your motor pulse step polarity set incorrectly. On Ruida controllers, each axis has a setting called PWM Rising Edge Valid. This setting tells the controller whether the rising edge or falling edge of a step pulse is what the motor driver is looking for, and fixing it may correct skewed engraving.

To fix this problem, Find the PWM Rising Edge Valid setting on the X axis, and toggle the value – enable it if it's disabled, or disable if it's enabled. Do the same for the Y axis.

What is this setting and why does it matter?

A step pulse is a transition from low to high, or high to low. The controller will hold the line low, and pulse it high, or hold the line high, and pulse it low. The transition itself is what matters, and motor drivers will either look for a transition from low to high (rising edge) or high to low (falling edge) to accept as a Step.

If the laser controller believes that the motor driver is looking for the leading edge signal (when it transitions from low to high), it will pulse the line, and could change the direction line immediately after that. If the motor driver is waiting for the falling edge, it will see the direction change BEFORE the falling edge of the pulse, meaning that it will change direction one step too soon.

image

In the image above, the upper line of steps is interpreted as 4 steps in one direction, then two in the other. The lower line is interpreted as 3 and 3, and the only difference is which side of the step signal the driver is looking for.

Start and End Delay

This feature adds in a delay at the start or end of jobs. This is often used to give fants time to get to speed at the start of job or finish venting the air in the laser before stopping.

For more help using LightBurn, please visit our forum to talk with LightBurn staff and users, or email support.