T2 Questions

[caperry88]

So I have started trying to work on some projects, the first being a circle with different shades of gray and a portion of white.   for some reason they all looked the same, whether I used black and white, dither, or grayscale.

[caperry88]

In addition I am having to flip the image in order for it to come out right on the wood.

[Zax]

Interesting. The result would make sense for "black and white" where the threshold value would change the point of transition but in dithered you should see the pattern and greyscale would be a variable power result.

You should see this on-screen and in the viewer, as shown on attached examples. (Note: I used a very small box zoomed in, so the dithering shows up)

The S values in G-Code would also reflect these settings, can you verify those are changing correctly?

I also can't explain the flip, are you using the default T2Laser parameters for Grbl?

It's easy to correct by changing Grbl parameters but I am unsure why it would be necessary.

- Zax

[caperry88]

So the flip is fixed simply by swapping the plugs.

As far as the grayscale, I need more investigation.  Do you have a small pic with settings to use in t2 that I could engrave and compare with one you have done zax?

[Zax]

The attached is what I used for above examples. If you see the same thing on-screen, and in the G-Code viewer then the issue is not in T2Laser but something with your system.

If it doesn't look like my example above then likely your power settings are wrong, check they are 0 to 255.

If it looks correct but doesn't work, then it suggests you aren't getting PWM laser control. Does your system have the L2 board?

I have not personally confirmed PWM capability on L2 but was planning to do so when I had time. Maybe someone else can confirm. J-Tech Grbl is 1kHz frequency, the LaserInk uses standard Grbl PWM frequency of 7.8kHz, so perhaps give that firmware a try? The higher frequency may work better.

- Zax

[caperry88]

If it doesn't look like my example above then likely your power settings are wrong, check they are 0 to 255.

I changed laser power to 0 to 150 and same result, to me it has to be that the PWM is not engaged.

If it looks correct but doesn't work, then it suggests you aren't getting PWM laser control. Does your system have the L2 board?

I will need to find the post in the forum explaining the differences and get back to you on that.

I have not personally confirmed PWM capability on L2 but was planning to do so when I had time. Maybe someone else can confirm. J-Tech Grbl is 1kHz frequency, the LaserInk uses standard Grbl PWM frequency of 7.8kHz, so perhaps give that firmware a try? The higher frequency may work better.

I will try this also and post an answer tonight or tomorrow, hopefully.

[caperry88]

So after further research it appears I have an L2 card.

I will Flash the laser ink  firmware to see if that will allow pwm, are there other things that I would need to test to see if pwm is available on the L2 card as I have already moved the jumper underneath the Nano card which allowed the jtech to be ran

[caperry88]

I performed an engraving of the shaded boxes below after flashing the LaserInk.hex

You can see not much difference in the shades.

[caperry88]

Next, I decided to re-flash the J-tech software and got the result below

Settings:

Feed Speed - 4000
Power - 0-250
Resolution - .1
Size: 30 (w) x 11.8 (h)
Threshold - .55

[caperry88]

The results above lead me to believe that I may have not had the J-tech flash properly or had another .hex instead. 

Observation:  The edges get extra dark from the laser start and restart occurring so close together and in the same spot.

Any ideas on the settings, I may try to use different settings with a slightly smaller pic to see exactly how much a difference some of them affect the output.


I did the attachment next and have come to the realization that the more contrast in shading the better off you would be.

[Zax]

Next, I decided to re-flash the J-tech software and got the result below
Settings:
Feed Speed - 4000
Power - 0-250
Resolution - .1
Size: 30 (w) x 11.8 (h)
Threshold - .55

That's starting to look really good, with different grain in the wood this is about the best you can achieve.

Just a note, your speed seems really high. Based on the dark outline you may need to bump up the acceleration and reduce the max speed value. In the code I do travel slightly beyond the outside to try and reduce this start/stop effect but if acceleration is low then it will still happen - to get a consistent shade you need an even speed.

Threshold is only applicable for black/white, it's the switch over grey point from white to black.

- Zax

[Zax]

I may have not had the J-tech flash properly or had another .hex instead.

Are you manually flashing the firmware?

How about the settings, are you using my defaults or your own?

I just want to understand if I should change anything in T2Laser, obviously I based everything on a sample of one (my system) and perhaps I need to fine tune it.

- Zax

[caperry88]

you may need to bump up the acceleration and reduce the max speed value

Where is the acceleration setting?

Threshold is only applicable for black/white, it's the switch over grey point from white to black.

Ok that makes sense that it doesn't do anything in the greyscale, it make for 1 less variable to work with.


I think I am going to take the shaded block and vary the shades more and make it small to run different settings and tests.

[Zax]

Where is the acceleration setting?

Currently T2Laser doesn't have an option to adjust the Grbl parameters, it can only download defaults. It's on the list for future improvements, along with axis swap.

You will need to change the $120 and $121 settings with a terminal program (UGS, Arduino IDE, CoolTerm etc.).

My default is 200, so if that's what you are using then perhaps up that to 300.

- Zax

[caperry88]

Are you manually flashing the firmware?

Yes, I am using the XLoader to flash the .hex files

How about the settings, are you using my defaults or your own?

Not sure what you are referring to, are you talking about flashing within the T2 Program?