⚠ STOP — READ BEFORE PROCEEDING

This procedure changes protected vendor-level laser settings, and the optional tuning in Part 2 can cause the tube to emit while the machine is idle.

An external pre-ignition value that is set too high will make the tube fire when it is not commanded to — commonly called laser leakage. You can no longer assume that an idle machine is not emitting. The lid/door interlocks and all other machine safety systems remain fully active and are not altered by this procedure, but the beam behavior at rest is.

By performing this procedure you acknowledge that you: (1) understand that you are editing vendor-level controller settings and have recorded the original values before writing new ones; (2) accept full responsibility for operating the machine in this state; (3) will notify every other operator with access to this machine; and (4) will not leave the machine in a state where laser leakage was observed — follow the restore section at the end of this article.

RF Tube Pre-Ignition Mode — Recommended Setting Change (ET-Series RF Tubes)

Overview

Based on recent R&D testing, Thunder Laser recommends changing the controller's pre-ignition mode on machines fitted with an ET-series RF laser tube. This is a preventative-maintenance change intended to improve the long-term stability and cutting performance of the tube.

The ET-series RF tube has its own built-in pre-ionization circuit with a pulse width of approximately 1.5%, so it does not need a pre-ignition signal from the controller. When the controller supplies an external pre-ignition pulse that is too narrow — the factory value is typically around 0.5% — it can interfere with the tube's own pre-ionization and reduce output stability.

The fix is to switch the controller's laser type from RF (with pre-ignition) to RF (no pre-ignition) so the machine relies on the tube's built-in pre-ionization instead.

Scope: This change applies only to ET-series RF tubes (ET-60 and ET-80). It is normally prescribed by Technical Support after diagnosing a specific symptom. Do not apply it to glass CO₂ tubes, fiber sources, or any non-ET RF tube. If you are not certain which tube your machine has, contact Technical Support before changing anything.

Before You Begin

• Confirm your tube type. This procedure is for ET-60 and ET-80 RF tubes only.
• Install and connect your laser software. LightBurn, RDWorks, or LaserMaker must be communicating with the machine before you can read or write controller settings. See the connection guides below.
• Read the current settings first. In every one of these tools you must click Read before you change anything, so the software is working from the machine's actual values instead of a blank form.
• Record the original values. Write down (or screenshot) the current laser mode and pre-ignition pulse value so you can put them back if needed.
• PPE: if you perform the optional tuning in Part 2, wear laser safety eyewear rated for 10.6µm and keep the lid closed any time the machine is powered and capable of firing.

Software Downloads and Connection Guides

Use whichever software you normally run with your machine. Not every package can make every change in this article — see the notes in Part 1 and Part 2.

Part 1 — Switch the Controller to RF (No Pre-Ignition)

Before making the change, confirm your laser software has successfully connected to the machine. Then follow the steps for the software you are using.

Use LightBurn or RDWorks for this step. LaserMaker does not currently offer a no-pre-ignition option for the RF laser mode, so it cannot make the Part 1 change. LaserMaker can still be used for the pre-ignition pulse tuning in Part 2.

Instruction	Reference Image & Video
LightBurn ① Go to Laser Tools > Machine Settings and click Read. (On older versions of LightBurn, Machine Settings is found under the Edit menu instead.) ② Under Vendor Settings, open Laser Settings. ③ Change RF (with pre-ignition) to RF (no pre-ignition). ④ Click Write to save the setting to the controller.	Video: Change pre-ignition mode in LightBurn
RDWorks ① Go to File > Vendor Settings and enter the password rd8888. ② Open the Laser tab and click Read. ③ Change RF Laser (Pre-ignition) to RF Laser (No Pre-ignition). ④ Click Write to save the setting to the controller.	Video: Change pre-ignition mode in RDWorks

Always click Read before you change a value, and change only the laser mode. Writing an incomplete or unread settings page back to the controller can overwrite unrelated machine parameters.

Verifying the Change

1. Click Read again and confirm the laser mode now shows the no-pre-ignition option.
2. Run a short test cut or engrave on scrap material and compare the result to what you were seeing before.
3. Look for the symptoms that prompted the change — inconsistent cut depth, broken engraving lines, or a missing start of a line — and confirm they are gone or reduced.

Part 2 (Optional) — If You Still See Interrupted or Delayed Laser Emission

After extended use, some tubes still show broken engraving lines or missing starting points even with the controller set to no pre-ignition. In that case you can re-enable the external pre-ignition signal and tune it up to a usable value.

Laser leakage risk — the tube can fire while the machine is idle.

Tuning the pre-ignition pulse upward deliberately walks the machine toward the point where the tube emits at rest. Keep the lid closed during every test, wear 10.6µm-rated laser safety eyewear, and never leave the machine unattended or in production while a leakage-producing value is loaded. Do not exceed 5% under any circumstances.

Target Values

• Starting value: 2% pre-ignition pulse width for ET-60 and ET-80 tubes.
• Adjustment step: reduce by 0.1% at a time.
• Goal: the highest pre-ignition pulse width that produces no laser leakage. In most cases this lands near 2%.
• Hard ceiling: never set the value above 5%.

The Leakage Test

1. Place a piece of thermal paper on the worktable at the machine's focal point.
2. Close the lid and leave the machine powered on and idle — do not run a job.
3. After a short dwell, open the lid and inspect the thermal paper. Any mark, scorch, or discoloration means the tube is leaking.
4. If leakage is present, lower the pre-ignition pulse value by 0.1%, write/upload the setting, and repeat the test.
5. Continue until the thermal paper comes out clean. That value — the highest one with no leakage — is your setting.

Setting the Pre-Ignition Pulse in RDWorks

Tutorial video: Set the Pre-ignition Pulse value in RDWorks

1. Go to File > Vendor Settings and enter the password rd8888.
2. Open the Laser tab and click Read.
3. Set the laser mode to RF Laser (Pre-ignition).
4. Set Pre-ignition Pulse to 2 and click Write.
5. Run the leakage test above. If leakage is observed, lower the value by 0.1, write it, and test again until the paper is clean.

Setting the Pre-Ignition Pulse in LaserMaker

Tutorial video: Set the Pre-ignition Pulse value in LaserMaker

1. Go to Settings > Vendor Setting and enter the password TL9501.
2. Open Laser Compensate and click Read.
3. Set Pre-ignition Pulse to 2 and click Upload.
4. Run the leakage test above. If leakage is observed, lower the value by 0.1, upload again, and re-test until the paper is clean.

LightBurn limitation: LightBurn currently accepts the pre-ignition pulse width only as a whole-number percentage (1%, 2%, and so on) — it will not take decimal values such as 1.5%. This has been reported to the LightBurn team and may be addressed in a future release. Until then, use RDWorks or LaserMaker when you need decimal precision. Part 1 of this article (switching the laser mode) works fine in LightBurn.

Reading the Results

• Success: engraving lines are continuous, line starts are present, and cut depth is consistent — with clean thermal paper at idle.
• Still unstable at 2%: the value may be raised further, but never above 5%, and only if the leakage test stays clean at each step.
• Leakage that will not clear: stop. Restore the setting to RF (no pre-ignition) and open a support ticket — persistent leakage points to a tube or RF power supply problem rather than a settings problem.

Restoring the Original Setting

1. Open the vendor settings page in LightBurn or RDWorks and click Read. The laser mode can only be changed from these two packages.
2. Set the laser mode back to the value you recorded before you started — or to RF (no pre-ignition) if you were tuning in Part 2 and could not clear the leakage.
3. Click Write, then click Read once more to confirm the controller accepted the change. (If you are only putting a pre-ignition pulse value back, LaserMaker can do that with Upload.)
4. Repeat the thermal-paper leakage test to confirm the machine is not emitting at idle before returning it to production.
5. Let any other operators know what was changed and what the machine is currently set to.