Average laser diameter, or smallest dot that can be made.

[jontelling]

Does anyone have the laser diameter being used?

Has anyone from the peachy team tried to make any small spheres in the resin to see how small (depending on the laser power and time) a single point really is?
Just wanting to know so I can work out the realistic resolution.
Jon.

[quertz]

Hey jontelling,

as far as I know, you cannot really talk about resolution in that way. Here are some points you might want to know:

1. The PeachyPrinter allows you to put apertures on the laser to get your own laser diameter.
2. The Problem is that even if the point is small, the laser will scatter in the resin and cure more than it should.
   This can be reduced by using opaque, colored resin (as you use normally). The Peachy guys use only slightly colored resin to make the defects more visible.
3. More Power means broader walls as there is more light to be scattered.
4. Even if you have a "big point" you still can get a good resolution. The only difference is the minimal wall thickness.
   You can observe this at filament printers like RepRap, Ultimaker & Co. They do have a "print-stroke-size" of roughly > 1 millimeter and still can get better resolution, but no wall thinner than a millimeter.

So to conclude,
you only want a thin laser if you need thin details.
Else you usually want a compromise that allows you to print faster.

I hope this answers your question.

Hava a nice day,
quertz

[jontelling]

Hey jontelling,

as far as I know, you cannot really talk about resolution in that way. Here are some points you might want to know:

1. The PeachyPrinter allows you to put apertures on the laser to get your own laser diameter.
2. The Problem is that even if the point is small, the laser will scatter in the resin and cure more than it should.
   This can be reduced by using opaque, colored resin (as you use normally). The Peachy guys use only slightly colored resin to make the defects more visible.
3. More Power means broader walls as there is more light to be scattered.
4. Even if you have a "big point" you still can get a good resolution. The only difference is the minimal wall thickness.
   You can observe this at filament printers like RepRap, Ultimaker & Co. They do have a "print-stroke-size" of roughly > 1 millimeter and still can get better resolution, but no wall thinner than a millimeter.

So to conclude,
you only want a thin laser if you need thin details.
Else you usually want a compromise that allows you to print faster.

I hope this answers your question.

Hava a nice day,
quertz

Thank you posting this (I think I had already read this before in an old thread).
I understand that the resolution cannot be quantified in this manner. I was unclear with my original question. I know the cure area of the resin is going to be a function of time/laser area/intensity and UV propagation.

UV propagation is based on the resin (semi-static) and the focus will change depending on the level (hence the request for average), intensity at the moment is static. So that leaves us with time, cure time is proportionate to the cross section of the laser, which is back to the average.

I was originally going to ask ‘what is the diameter of the laser’.

I hope I’m making sense. To put it another way, if I was to keep the laser center during the whole build how thick would the cylinder be.

[Chayat]

I hope I’m making sense. To put it another way, if I was to keep the laser center during the whole build how thick would the cylinder be.

I think even in that very simple set-up your answer will have a lot to do with how fast your dripper is going and how much dye there is in your resin.

[jontelling]

I think even in that very simple set-up your answer will have a lot to do with how fast your dripper is going and how much dye there is in your resin.

OK, Last question.
What's the diameter of the laser leaving the diode. Nothing else. Just this.
EDIT: Or if you know the make/model of laser diode that will do

[rylangrayston]

ok off the top of my head here are some numbers for you:

- laser spot size focused at infinity is 2.5 mm with no aperture ( thats approximately.. its oval looking because the chip that emits the light is actually rectangular )
- we typically print with an aperture between 1mm and .3 mm diameter
- the thinnest wall we have printed is about .2 mm
- we typically print walls between .3 and .5 mm thick
- we typically focus the beam at infinity
- the thickest wall we have ever printed is about 2 mm wide.... actually perhaps ive done 5 mm wide, but that was before the campaign and it was very ugly.

-my intuition ( alto i haven't done this yet) is that if you were to take the basic kit with a .1mm aperture, and place the printer only 2 inches away from the resin
you could get was as thin as .1 mm.

if you leave the laser on in one spot and let the printer drip, you can get shafts that are .3mm in diameter.... the amazing thing is how tall you can make them
I have printed a .5 mm diameter shaft that is 5 inches tall, and it wouldnt be hard to go taller. Its also fundamentally the fastest thing you can print.

[oninoshiko]

ok off the top of my head here are some numbers for you:

- laser spot size focused at infinity is 2.5 mm with no aperture ( thats approximately.. its oval looking because the chip that emits the light is actually rectangular )
- we typically print with an aperture between 1mm and .3 mm diameter
- the thinnest wall we have printed is about .2 mm
- we typically print walls between .3 and .5 mm thick
- we typically focus the beam at infinity
- the thickest wall we have ever printed is about 2 mm wide.... actually perhaps ive done 5 mm wide, but that was before the campaign and it was very ugly.

-my intuition ( alto i haven't done this yet) is that if you were to take the basic kit with a .1mm aperture, and place the printer only 2 inches away from the resin
you could get was as thin as .1 mm.

if you leave the laser on in one spot and let the printer drip, you can get shafts that are .3mm in diameter.... the amazing thing is how tall you can make them
I have printed a .5 mm diameter shaft that is 5 inches tall, and it wouldnt be hard to go taller. Its also fundamentally the fastest thing you can print.

since 5mm was early in the campaign, do you think that it would be less ugly now, or would it be a better approach to just make something like a honeycomb structure if you needed something with more strength?

[jontelling]

ok off the top of my head here are some numbers for you:

- laser spot size focused at infinity is 2.5 mm with no aperture ( thats approximately.. its oval looking because the chip that emits the light is actually rectangular )
- we typically print with an aperture between 1mm and .3 mm diameter
- the thinnest wall we have printed is about .2 mm
- we typically print walls between .3 and .5 mm thick
- we typically focus the beam at infinity
- the thickest wall we have ever printed is about 2 mm wide.... actually perhaps ive done 5 mm wide, but that was before the campaign and it was very ugly.

-my intuition ( alto i haven't done this yet) is that if you were to take the basic kit with a .1mm aperture, and place the printer only 2 inches away from the resin
you could get was as thin as .1 mm.

if you leave the laser on in one spot and let the printer drip, you can get shafts that are .3mm in diameter.... the amazing thing is how tall you can make them
I have printed a .5 mm diameter shaft that is 5 inches tall, and it wouldnt be hard to go taller. Its also fundamentally the fastest thing you can print.

No wonder you’re eager to get the continual focusing sorted.
You’re wasting 98.6% of the laser power when using an aperture of 0.3mm
Just think, if the mirrors and z-axis can handle it you could print 70x faster (? I know, it’s the numbers not real like, ).

I’ll add be adding a focusing setup to my mod list (should be rather easy if I can deal with gear slack)

Thank you for providing the numbers, really helps.

[rylangrayston]

since 5mm was early in the campaign, do you think that it would be less ugly now, or would it be a better approach to just make something like a honeycomb structure if you needed something with more strength?

Yes I think the peachy printer can do things like honey comb infill now.