Author Topic: T2 Laser help with greyscale  (Read 121 times)

lxpeery

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T2 Laser help with greyscale
« on: January 19, 2019, 04:33:44 PM »
Total noob here, so forgive me for asking a dumb question.

I have a cheap Chinese 2.5W laser (eleksmaker). I've been trying to get greyscale figured out running T2 Laser. I can't seem to get more than two or three shades down. On this run of one of the shading wheels I found on this forum, I can see about three different shades. 5%-15% looks about the same, then about 20%-50% is about the same, then from there on up is pretty much one shade. Maybe a little darker at the top. I certainly can't get good distinction between the individual power levels. This was done with the full power range, 700 speed, diagonal printing, and using the greyscale setting with no acceleration. The laser is a PWM module, so I feel like it should be able to get a little better than this.

What settings do I need to start playing with? Only thing I've done much with is changing the speed, but that just seems to make the entire "shade wheel" darker, without improving contrast.

On an unrelated topic, is there a method other than acceleration for reducing the time spent moving over dead space? It feels like most of the time the program is running the laser is off and moving over space where the laser is off. On bigger jobs, that can add up to hours of time where the laser is just moving to the next space where it actually burns something. If I remember right, the stock program that came with the Eleksmaker was a little better about avoiding dead space. For example, the laser would knock out one chunk of the image being burned and then move on to the next. That program was very limited in features and T2 is obviously better, but that was one nice feature.

Thanks for the help!


ggallant571

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Re: T2 Laser help with greyscale
« Reply #1 on: January 19, 2019, 05:36:21 PM »
Did you stain or otherwise prepare the wood? Shading is very much medium dependent.

I don't understand 0 acceleration. Is it a grbl feature to not do the acceleration profile?
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lxpeery

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Re: T2 Laser help with greyscale
« Reply #2 on: January 19, 2019, 10:24:27 PM »
This particular piece was stained, it's a scrap I had laying around from another project. However, I've noticed no difference between raw and treated material, and other mediums have similar results.

Zax

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Re: T2 Laser help with greyscale
« Reply #3 on: January 20, 2019, 03:51:11 AM »
I actually think that looks pretty good given the medium. Is that with my firmware?

What laser do you have? If it's one of the EleksMaker blue anodized TTL lasers you should get better results, the black aluminum lasers (PWM) are older tech and don't produce many shades.

Dithered and Velocity Mode can both produce (pseudo) grey scale on materials that won't produce shading or with non-TTL lasers.

Rapid Skip Blank (Settings / Image Options) may be what you are looking for.

lxpeery

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Re: T2 Laser help with greyscale
« Reply #4 on: January 20, 2019, 12:41:38 PM »
I actually think that looks pretty good given the medium. Is that with my firmware?

What laser do you have? If it's one of the EleksMaker blue anodized TTL lasers you should get better results, the black aluminum lasers (PWM) are older tech and don't produce many shades.

Dithered and Velocity Mode can both produce (pseudo) grey scale on materials that won't produce shading or with non-TTL lasers.

Rapid Skip Blank (Settings / Image Options) may be what you are looking for.

Thanks for the response Zax, this is your firmware and has always worked great. I'll look into that skip blank setting too, that sounds exactly like what I'm looking for.

This is the blue anodized laser, I bought it fairly recently so I would hope that it would be the updated model.

So if this is a good result for the medium, what wood can be used to get better results? I know this is a cheap laser, but I've seen people get pretty impressive grayscale images with the same module, so if there's something that I can change to improve my results, I'd like to do so.

Thanks!

ggallant571

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Re: T2 Laser help with greyscale
« Reply #5 on: January 20, 2019, 01:42:47 PM »
I have had good results with 1/32 birch plywood available at Michaels and other craft stores. The lower power setting have little effect but the middle has more. Stainng or applying a pre-stain reduces the effective range. You also have to play with the burn speed.
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Zax

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Re: T2 Laser help with greyscale
« Reply #6 on: January 20, 2019, 02:32:35 PM »
I use birch ply, it seems to provide the best resolution and shading.

I've heard of equally good results with alder but haven't found a good source for it locally.