LCD Based 3D Printer - Introduction

This is the place to discuss DLP projectors, UV Lasers, Galvanometers, LCD screens and similar display devices. Also discussed are optics in general.
AndersonTa
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Location: Houston, TX
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Re: New Builder - LCD Based 3D Printer - Introduction

Postby AndersonTa » Tue May 13, 2014 1:51 am

Woah, that LED array is not the solution I was hoping for.

You are def going bigger than I was hoping for, 8" square was the MAX for my wants/needs.

I was also thinking of incorporating the tilt/release mechanism around the LCD.
@AndersonHTa

Oneminde
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Re: New Builder - LCD Based 3D Printer - Introduction

Postby Oneminde » Tue May 13, 2014 3:40 am

Phife wrote:This is the LED array, 320 pcs of 3w 410nm LED's, and 6 degree collimation optics. Custom Metal core PCB and it gets attached to a large heatsink for cooling as this thing gets hot!
I made it modular and scalable so it can be made larger or smaller to suit different size LCD's.

Nice. I will build a top-down printer with a one z-axis configuration and some of the things you mention in regards to UV and how it impacts the crystals bear merit. Will you use a diffusion layer between your LED array and the LCD panel ?

Phife
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Re: New Builder - LCD Based 3D Printer - Introduction

Postby Phife » Tue May 13, 2014 9:47 am

AndersonTa wrote:Woah, that LED array is not the solution I was hoping for.

You are def going bigger than I was hoping for, 8" square was the MAX for my wants/needs.

I was also thinking of incorporating the tilt/release mechanism around the LCD.



Lol, that array is actually 4 smaller array stuck side by side.. each smaller array holds 80 LED's and is about 200mm x 160mm, should work well for a 8" panel. Im using a 21" panel.

Im using a special release method.. actually I am able to do many different types of release. I have the Dual Z so I can do a Muve style tilt release, I also have a FEP Film that is directly over the LCD's surface. Its currently just hanging over it and the weight of the resin pushes it down over the LCD, the film can move to help peel. I can pump air or fluid in the space between the FEP and LCD to help release if needed.

Phife
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Re: New Builder - LCD Based 3D Printer - Introduction

Postby Phife » Tue May 13, 2014 9:49 am

Oneminde wrote:
Phife wrote:This is the LED array, 320 pcs of 3w 410nm LED's, and 6 degree collimation optics. Custom Metal core PCB and it gets attached to a large heatsink for cooling as this thing gets hot!
I made it modular and scalable so it can be made larger or smaller to suit different size LCD's.

Nice. I will build a top-down printer with a one z-axis configuration and some of the things you mention in regards to UV and how it impacts the crystals bear merit. Will you use a diffusion layer between your LED array and the LCD panel ?



I dont think I will be using a diffusion layer, I want to maintain a nicely collimated beam of light, the diffusion layer will just scatter the light and I think it will just cause issues. The lenses Ive chosen are very uniform in their output. When I have the PCB's I'll know more about how even it really is.

Oneminde
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Re: New Builder - LCD Based 3D Printer - Introduction

Postby Oneminde » Tue May 13, 2014 10:26 am

Phife wrote:I dont think I will be using a diffusion layer, I want to maintain a nicely collimated beam of light, the diffusion layer will just scatter the light and I think it will just cause issues. The lenses Ive chosen are very uniform in their output. When I have the PCB's I'll know more about how even it really is.

Right, you have a point there in regards to the diffusion.

I have a somewhat different approach to the resin and LCD interaction. As I see it, with limited knowledge at hand, the closer the masking is to the working surface, the finer the result will be. Aka, less scattering of the photons that are suppose to do the work on the photomonomer. Scattering in this case is a bad thing, it makes the edges and so on "fuzzy". We like sharp and clean edges as well as Voxel surfaces (continuous operation). So with my top-down, I will add a resin pressure solution.

VAT - Resin (1-2 mm) - Thin glass or Plexi / Lexan sheet (1-2mm) - LCD. - In this manor I can mechanically limit the distance between the VAT and LCD surface to under 5 mm. If you look at Envisiontec Ultra, they use a similar solution. If you have a closed compartment, sealing the VAT and resin and have the resin level higher than at the absolute VAT & glass section, outside of the working area, pressure is created between the VAT & Glass section. Less diffusion is then allowed to occur and the mechanical distance will always be the same since the growth per layer is calibrated to the Z axis speed = the same. The sett up is then less likely to be sensitive to vibration that can alter the photomonomer interaction with the projected image, in relationship to sloshing and other types of vibrations that can happen since the action or force of that is taking place in the non pressurised "overflow" area were excess photomonomer exist.

I am not a huge fan of bottom-up printers, like the Form1 due to the fact that there will probably be and probably is a mass and weight limit. Using gravity as in the top-down solution, one can print infinitely deep, not that, that is the goal... lol, but you catch my drift here or so I will presume :D - One can always change the depth mechanically.

As a group and working with open source, the target should be; High quality, large working area at an affordable price. That is why I as you and a few others here figured out that if a solution for using LCD/TN/TFT panels can be used, with a good PPI and resolution as well as large panel size, the work achieved here can set a new record in terms of financial investment per inch manufactured. The machine alone with a printing surface similar to the 24" monitor you use is in the $100K area and dominated by a few company's, so in affect, we have at the moment a monopoly and that is never good when it comes to evolution of technology.

But that is how I see it. And, the challenge besides the printer itself is monomers, different types, should also come at an affordable price. Spot-A have 4 and working on more materials (visible light cured) that comes at an affordable price, so far. I think it is about $90,- / kg

Monomers or photopolymers is something I just started looking at and boy o boy is there much too learn.

My 2 cents so far ;)

Oneminde
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Re: New Builder - LCD Based 3D Printer - Introduction

Postby Oneminde » Tue May 13, 2014 5:09 pm

I just realised all the model kits I will be able to construct and print with this machine :D

Oneminde
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Re: New Builder - LCD Based 3D Printer - Introduction

Postby Oneminde » Sat May 17, 2014 9:19 am

So, were did everyone go and is there any news.. any. Something would be great :D

Oneminde
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Re: New Builder - LCD Based 3D Printer - Introduction

Postby Oneminde » Wed May 21, 2014 5:58 am

I just read in a science book that the human eye cannot see finer details than 0.1 mm or 100 microns. Worth knowing so that we don't overdo things.

Finhead
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Re: New Builder - LCD Based 3D Printer - Introduction

Postby Finhead » Wed May 21, 2014 10:51 am

Oneminde wrote:I just read in a science book that the human eye cannot see finer details than 0.1 mm or 100 microns. Worth knowing so that we don't overdo things.


I dunno what book you read that in but certainly not the case at all. I can for sure see a difference (the layers) going from 100 to 75 and to 50 microns, clear as day. Maybe they needed glasses. lol :lol:

Oneminde
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Re: New Builder - LCD Based 3D Printer - Introduction

Postby Oneminde » Wed May 21, 2014 12:42 pm

Finhead wrote:
Oneminde wrote:I just read in a science book that the human eye cannot see finer details than 0.1 mm or 100 microns. Worth knowing so that we don't overdo things.

I dunno what book you read that in but certainly not the case at all. I can for sure see a difference (the layers) going from 100 to 75 and to 50 microns, clear as day. Maybe they needed glasses. lol :lol:

That might be true and I will get an opportunity when I calibrate my machine to discover that also. I do not own a printer atm, so the LCD-SLA will be my first.

Its good that people are back in this tread, the best on the planet atm :D