The laser won't fire on my TTC-450 + 20 W Laser Module

I have a TTC-450 CNC and use it for carving. I purchased the 20W laser module and installed it. The laser will fire if I manually use the TTC450’s touchscreen to turn on the “spindle” (now wired to power the laser) and the X/Y/Z movement works as normal.

I’m using a MacBook Pro running the latest OSX 14.

I am running the latest LightBurn. Lightburn will move the CNC head with the laser no problem, but won’t fire the laser.

I get this console output:
Starting stream
Layer COO
[MSG:M4 requires laser mode or a reversable spindle]
error:20
Unsupported or invalid g-code command found in block.
On or near line 2:
Stream completed in 0:00
ok ok ok ok ok
[MSG:Program End]
ok

After browsing this forum, I did make sure rotary mode is OFF and laser mode is ON, with S-value max set to 1000.

Here is the G-code of the simple square I’m using as a test object:
; LightBurn 1.4.03
; GRBL device profile, absolute coords
; Bounds: X27 Y22 to X66 Y61
G00 G17 G40 G21 G54
G90
M4
; Cut @ 6000 mm/min, 20% power
M8
G0 X27Y22
; Layer C00
G1 Y61S200F6000
G1 X66
G1 Y22
G1 X27
M9
G1 S0
M5
G90
; return to user-defined finish pos
G0 X0 Y0
M2

Could someone please recommend settings that will allow LightBurn to fire the laser? Thank you so much for your help!

The problem is your firmware has $32 set to zero
You need to see what is the firmware default but $32=1 should be default

if not it will error out

do $$ in console and post here the output?

Thank you. $32 is already set to 1

Here is the $$ output:
$$
$0=10
$1=25
$2=0
$3=7
$4=0
$5=1
$6=1
$10=1
$11=0.010
$12=0.002
$13=0
$20=0
$21=1
$22=1
$23=3
$24=300.000
$25=500.000
$26=250.000
$27=1.000
$28=1920.000
$30=10000.000
$31=0.000
$50=5.000
$49=19.500
$32=1
$38=0
$40=1
$100=800.000
$101=800.000
$102=800.000
$103=100.000
$104=100.000
$105=100.000
$110=750.000
$111=750.000
$112=750.000
$113=1000.000
$114=1000.000
$115=1000.000
$120=400.000
$121=400.000
$122=400.000
$123=200.000
$124=200.000
$125=200.000
$130=450.000
$131=450.000
$132=80.000
$133=300.000
$134=300.000
$135=300.000
ok

this is a very wonky output

Question. are you on latest firmware?
Are you using GRBL in the devices? make sure is not GRBL M3 or GRBL LPC by mistake

Svalue Max should be 1000 not 10000
I would $RST=* in console to set all to defaults
Try to update firmware if any available
And then also reconfirm your lightburn profile

(I have also set $32=1 manually for good measure, and tried Svalue max = 1000 and 10000, laser power at 10%, 20%, and 50%, all without any firing, even though the head moves properly).

Thank you for your help!

Thank you-- I will try to do a firmware update for the CNC and will report back.

Make sure to recheck the profile too
Is odd that LCD can fire and the command cannot, so it seems firmware/Profile related

Thank you. The profile of the Device is set to GRBL, which was the device setting naturally discovered. The Mac is connected to the TTC-450 via USB cable.

Can you type $I in console and paste results?

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Here is the $I output:

$I
ok
[ORIGIN:China]
[PRODUCER:MKS_DLC32]
[DATE:20220905]
[VER:1.1h.2023070302:]
[OPT:VPHSW,15,256]
Target buffer size found
[MSG:Machine Name:MKS DLC32]
[MSG:Mode=STA:SSID=Ether:Status=Connected:IP=10.0.7.194:MAC=
C4-DE-E2-0B-D5-DC]
ok

The firmware appears to be newer than the one provided with the machine on its micro-SD card, so I don’t think firmware updating will help.

Svalue Max needs to be equal to the $30 value.

Do you have a voltmeter?

:smile_cat:

point was Firmware is not on defaults

Guess I don’t follow you…

:smile_cat:

Considering Max Svalue is by default 1000
And it was altered, i assumed that the whole firmware had to be reset
And or. something wonky was happening at the the firmware $$ level

so that would be first step, to firmware reset/Update

Is Lightburn default setting… My grbl firmware defaulted to $30 = 255

The two just need to be equal. The 1000 value is probably best for a 16/32bit machine.


I don’t upgrade firmware unless there is a clear and compelling reason to do so…

Good luck

:smile_cat:

Only GRBL m3 defaults to 255
GRBL is 1000

Point was, something was really outside the expected values, be it 255 or 1000
10000 is default to nothing :smiley:

After researching YouTube and reading a bunch of outdated and non-English information, I finally hypothesized that the firmware of the CNC either supports CNC spindle mode or laser mode but not both. In other words, there are two parallel firmware streams for the TTC-450, one for spindle work and one for laser work.

Once I realized this, I reflashed the firmware with the laser firmware and now LightBurn has no problem turning on the laser.

But now two new problems have been created:

  1. Oddly the Y axis is inverted now so it grows in value as the head approaches the front of the unit. As if the 0,0 origin is in the rear left instead of the front left corner. This isn’t a huge deal, just an annoyance given what I’m used to.

  2. A bigger issue is the scaling is way off now, so an object that is supposed to be 200 mm is burned at a size of about 30 mm. I assume this is fixable somehow, but what’s the most elegant way to do so? I would rather not simply upscale my artwork beyond the borders of the document knowing that the laser will scale them down.

Thank you!

Did you $RST=* after firmware update
EPROM values persist firmware update (most times)

Do a $$ dump, then $RST=* in console
$$ again, compare values

This said, TT should really provide a update firmware that made machine just work
Get to them see what they say

As a side note, from their website: this shoudl be the firmware defaults

$0=10
$1=25
$2=0
$3=7
$4=0
$5=1
$6=1
$10=1
$11=0.010
$12=0.002
$13=0
$20=0
$21=1
$22=1
$23=3
$24=300.000
$25=800.000
$26=250.000
$27=1.000
$28=1920.000
$30=10000.000
$31=0.000
$32=0
$38=1
$40=1
$100=800.000
$101=800.000
$102=800.000
$103=100.000
$104=100.000
$105=100.000
$110=800.000
$111=800.000
$112=800.000
$113=1000.000
$114=1000.000
$115=1000.000
$120=400.000
$121=400.000
$122=400.000
$123=200.000
$124=200.000
$125=200.000
$130=450.000
$131=450.000
$132=80.000
$133=300.000
$134=300.000
$135=300.000

All 8-bit Arduino GRBL firmware will also default to 255.

There are some boards that do dual-duty as CNC and laser that are configured for 10,000.

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