Re: [diy_3d_printing_and_fabrication] Re: LCD Based Printer; Photopolymer Samples
- Hi Nick!
Thanks for replying to my post, I was hoping you might.
It's great to hear from a fellow Canadian! I'm in Toronto (East), how about you?
I think it's awesome that you're planning to release a DIY kit for this sort of project. Also self replication is a good idea. If you're working on software, does that mean the mechanical/optical/chemical parts of the printer are working well now?
If you have a minute, I have a few questions for you:
What exactly was wrong with a color LCD, were the blue color filters and red/green pixels just blocking too much of the useful light?
How did you manage to solve the issue of diffusion of light leaving the LCD Panel? Was it enough to simply use the LCD panel itself as the vat bottom? Does the light from the MH lamp need to be collimated?
What kinds of cure times do you get?
I read a lot about metal-halide and mercury vapour bulbs over the last few days, and I had looked into some MH lamps made for aquariums - They seem to have the types of spectral output you mentioned. A custom lamp must have been pretty expensive! Similarly with the Monochrome LCD panels - the only place I can find them is on eBay, and they are very expensive - $700 to $1000. I was hoping to get going with a plain color LCD which can be gutted from a photoframe for ~$50. I assume you've found a way to get monochrome LCDs for cheap, if you plan a DIY kit?
I'm certainly looking forward to when you have a chance to write about everything you've learned through the testing process. I think I'll start experimenting too, I just finished building a CNC router and I'm looking for a new project to use it for :p
AliOn Thu, Feb 21, 2013 at 10:53 PM, phife54@... <phife54@...> wrote:
A fellow Canadian, where abouts are you?
I have been developing an LCD based 3d printer for the last 6 months, While my thread has been quiet for some time, rest assured ive been plugging away at it.. Its not been a simple matter. Ive done a lot of testing with different resins, LCD's, Light sources, Lenses, and Electronics.
I am hoping to release a DIY kit for others to build their own LCD 3D printer. Im working with Chris Marion and we are developing a great machine, I will be using a custom version of Chris's software.
Dont waste your time with color LCD, you will need a monochrome LCD no matter what.
My current setup is using a custom 400w MH bulb on a digital ballast, this bulb has a small arc and a very high output in the 390-420nm range and has a large spike at 450nm and not much of the spectrum after that, its a very nice purple/blue color. Optics are very important, and dealing with the heat of the 400w MH bulb must also be address.
I havent had much success with any other bulbs, I was testing with a 150w MH and a regular 400w MH but they didnt work out.
The nice thing about the LCD printer is the large build area, I hope to be able to print the entire structure of the printer with the prototype in a reprap style. Print panels, add hardware and electronics and you got a printer. Ive been designing printable panels but there is much to deal with before I even begin printing other machines.
You will have to deal with all the issues youve listed and more, and its a big task. I encourage you to experiment and try. To start off save you money and dont bother with color LCD's get a monochrome or greyscale LCD used for medical purposes, x-ray imaging.
If you wait a couple more months I hope to have a working printer and I can spend some time getting a DIY kit out there and write up all that ive learned from my testing ao rhat others can make their own.
I wish you luck!