I need help setting up this machine

[donwatson]

@ggallant571, could I reduce the uncertainty by purchasing better/costlier components ?? I was hoping to (one day) cut 5mm (1/4") plywood, would this be feasible ? Is there a laser to fit this machine that will cut 5mm ply ?? So many questions I don't really know where to start.

@ThothLoki, I was burning at 0.2. I shall do a burn at 0.1 and report back.

Thanks for the help chaps.

Don W

[donwatson]

I have burned Tweety at 0.1 and this is how he turned out. A little darker, a bit more solid looking. This is the first time I have managed 2  burns without the pattern shifting. Is there any simple raster burns that will give me some idea of what is going wrong when it does go wrong ??

[ggallant571]

You have already done the power. Wait till something completely dies or you really want some feature. BTW - I only etch at 0.1mm (it is all my host application does!!!). I also set  images to 254dpi so what I see is sometimes what I get.

[Zax]

It's looking much better, sounds like your power supply was the problem.

Most lasers are 0.12 to 0.16 spot size, using smaller values results in over burning and larger values in gaps.

To improve speed I usually de-focus the laser slightly (not the smallest possible beam) and use 0.16~0.18, this only works if you have enough power.

[donwatson]

Thanks for this information chaps, it takes me a while to get it working.
I burned some samples last night of the grayscale and this was the result. Try 1 and 2 was at the size on the Samples page and Try_3 was at twice the size. There was some serious black dust when doing these and I tried with a vacuum cleaner to clear both smoke and dust as they were burning. The grayscale is a bit disappointing but it may get better when I learn what I am doing wrong.
take care
Don W

 

[Zax]

Do you have a TTL (3 wire) laser?

If so, yes that's not very good. It does depend on the material, but I would expect better graduation.

If it's a non-TTL laser you need to use Velocity or Dithered modes.

[donwatson]

Thanks Zax,
What is a TTL 3 wire) laser??
I can take a photograph if it helps ??

Don W

[ggallant571]

The cable between the controller and the laser module. Often labeled Vcc, GND, PWM, The alternative is a 2-wire.

[donwatson]

Thanks ggallant571,
I have attached a pic. of what I have. Does this help ?
Don W

[Zax]

That is most likely not a TTL laser as it only has 2 wires going to the laser module.

You should try Dithered and Velocity Modes, they will significantly improve your grey scale results.

[donwatson]

Thanks Zax,
I will have a go at trying that in the morning

Don W

[donwatson]

I have attached a couple of pictures of yesterday's work. There is a big difference between the start and end pictures although that may not show too well in the pics. There seems to be quite a bit of adjustment needed when setting up an engraving with greyscale, feed rate, dithered etc. and a lot depends on the material. It looks as if it needs a lot of practice with actual objects/materials rather than practicing on scales.

[Zax]

You are correct, all materials act differently and some just don't work at all. It is certainly trial and error, each laser is different too.

Dithered is usually the easiest to use as it only uses full power on/off pulses, Velocity can be the hardest to setup but for the best graduated grey scale it's usually the best result.