So, I found out two things yesterday.

First, the Fire HDX LCD is really easy to remove the backing sheet, allowing for UV backlighting! This is going to be a much easier path forward than using the iPad screen, even though it's more expensive. Now I just need to find my UV LEDs that I bought.

Second, I found the 4K LCD from the Dell XPS 13 on Aliexpress (12.5" diagonal, ~72 micron X/Y). Same pinout as the 15.6" 4K screen that I already have, meaning the adapter board will work fine, so...

Must. Not. Purchase......

I may need to purchase new bottles of resin. They are almost a year old by now, and have been in freezing temperatures at least a few times. That can't be good for them. At least I can get Wanhao and Monocure resin from Amazon now.

I'm really hoping to get some time to work on the LCD mount this weekend.

 

I have a design for the top plate worked out. I'm trying desperately to print it as one piece, but it's proving difficult. Even though I bought MIC-6 cast tool plate for the print bed on my C-Beam printer, it looks like the shearing process when the metal house cut the plate caused the front right corner of my build plate to sit a little lower than the rest of the plate. Having not printed anything nearly as big as this (293mmx293mm on a 300mmx300m build area), I hadn't found the problem until now (MIC-6 tool plate is ground flat after it's cast, which is why I wanted to used it). I have to tweak the plate tonight to see if I can get it a little flatter.

 

xGoogle and LGD developed a 1443 PPI 4.3" 120Hz VR AMOLED display | OLED-Info

Drooooooool. Just make an LCD version please

(theoretical 17.4 micron X/Y resolution in case you were interested)

 

I LOVE CARBON FIBER FILAMENT!!!

It prints sooooo nicely, and all I had to do was increase the nozzle temperature by 10C. I've been printing with it all weekend and it's great (other than the nozzle wear issues). Parts look so much cleaner with them being in flat gray. The parts feel light and stiff too.

So, while I was hoping to be able to print the top plate in one part, the poor flatness of my build platform prevented that. As a result, I chopped it into 4 parts and printed them separately. Took a lot longer, but they came out looking great. Hoping to glue them together tonight.

Also should have the new vat sitting on the printer waiting for me once I get home.


After some digging around in the garage yesterday, I found the belt reduction kits that I got way back when. Thinking of installing one on the Z-axis to increase resolution, but still wondering if it's worth the effort if the lead screw and plastic anti-backlash nut won't allow for movement that small. Just gonna have to try and see I guess.

 

I'm glad to be back at it too! It's nice to have a workspace in the house now, so my kids are more likely to come see what I'm up to. My 5yo daughter has taken an interest in the 3D printer, so she's always asking "Daddy, can we print something?" Really hoping to instill the curiosity and desire to build and tinker in her and her brother (he's only 3, so early days yet). Anyway...

I'm looking forward to the first print. Hoping to be able to do that in a few weeks. I have to order some power supplies to run everything, and an LED driver for the UV backlight. I have everything else I need, providing I can find the roll of FEP film that's somewhere in the garage!

I have some pictures of the new parts that I printed, but I'm looking for a Photobucket alternative to host the pictures now that they have decided to be greedy Any suggestions?

 

So, Imgur will have to do for now. Anyway, progress!



Here is the top plate. Ended up having to split it into 4 due to the poor flatness of my print bed (that is in the process of being remedied). Lap joints everywhere for strength of course. I may re-print this later once I get a flatter print bed (there are a few minor tweaks I want to make, but weren't needed to get started)

The LCD is resting in there for the moment. The bottom of the screen has the ribbon cables, and as a result is a tiny bit thicker than the rest. I need to shave the support under that side (closest to the Z-axis) so that it sits flat front to back. The idea I have in my head is to leave the LCD proud of the top plate by a few tenths of a millimeter so that the FEP film on the vat is tensioned even more and guarantees that it's as close to the LCD as possible once the vat is tightened down.


Top side of the vat



Bottom side. The reduced thickness part is where the FEP film will be taped to. All corners are rounded to reduce the chance of tearing. This also slots in the guide on the top plate.



This carbon fiber filament prints so nicely!



Vat in place! The inside is larger than the LCD. This is so I can tension the FEP film, as mentioned earlier, and so that I can guarantee that the print area is as large as possible.

Currently working on the build platform mount. Should have the design finished on that in a few days, and printed this weekend.

 

LED mockup

 

The Sharp 4k screen would be fun, but I really need to get at least one of these built before thinking about getting that LCD

No diffuser for me. I'll be using a reflector similar to the way the Wanhao D7 is set up. I'll run one 30w led lor now, but I think two will be needed. The reflector will be made from thin aluminum flashing (cheap, easy to cut and form) and painted flat white. Flat white paint is a great specular diffuser and will help make the light dispersion more even than a polished or mirrored surface.

A large array of smaller LEDs would be better, but far more costly in comparison. I've been getting 30w 395nm LEDs for $14.

 

What resin are you using? What LED driver? Has the LCD been modified to allow light to pass through from the back?

 

Justintime is right. The volume that we would be dealing with for a group buy probably wouldn't get us much of a discount. Anything is possible though, but we would need to secure a good number of people to buy in to make it worthwhile. I've organized group buys in the past for LEDs and such, and it's no fun. The price of LCDs at this point are so low though.

If we were going to go after a bulk buy of LCDs, then a high resolution monochrome screen would be what to go after, but those are very expensive, even in volume.

As for what to look for, you want the highest resolution possible for the screen size. 1080p is too low of a resolution for all but the smallest screens for fine detail.

You can use this calculator to get a rough idea of the dot pitch for a screen. Smaller the dot pitch, finer the detail.

DPI Calculator / PPI Calculator

2k resolution screens are very common from 5" to about 10". Beyond that size you need to look for 4k screens to maintain detail.

 

That's a variant of the same LCD I bought last year. I ended up with the LP156UD1-SPA2.

There are a few 4k screens smaller than that, but the 15.6" screens are more common and will still offer pretty good print resolution.

 

Well, a brighter backlight will help a little, but relying on the LCD backlight limits you to daylight curable resins (resins that cure with blue light, not UV). This will severely limit your selection, and cure times will be much slower.

Ideally you want to modify the LCD so that you remove the aluminum back shell and any reflective sheets (usually white) so that you can shine high power UV LEDs through the screen. UV resins are much more readily available, and you will be able to use clear resins (daylight resins need the pigment to cure).

I have a suspicion that you may not have read through this thread in it's entirety. Most of the things that we have been discussing now has been gone over already. Not that I mind answering your questions, but I may have answered some questions that you didn't know you were going to ask

 

Lol, it's cool man. It is a lot to go through, and you're right, it's not always the most focused. There is a lot of useful information in this thread though, especially when it comes to the LCDs. I don't have a "here, buy this" list, as we are still figuring stuff out as we go, but it's getting there.

And the house is going well. Waiting for the weather to improve a little so we can start doing more work. I have a little workspace in the basement, so I'm happy

 

You're not wrong. That's how the technology got it's start, but it has evolved so much beyond that now. LCD is Liquid Crystal Display. Basically, there are cells in the screen that can change their opacity with the application of current. Same concept holds true for basic calculator screens and high resolution TV's, laptops, and phones. There's obviously a little more to it than that, but you get the idea.

As for flooding, I fortunately don't have to worry about that. We do have a river going through the back of the subdivision, but it's small and we are on a decent elevation. The previous owners had a French drain put in to mitigate any water penetration, so I shouldn't have to worry too greatly. We've had a few heavy rains since moving in, and it's dry as a bone. I do have to get a battery backup for the sump pump though.

 

Looks fun. Ideally, this is the way to go. Looks like 5050 size UV LEDs are getting cheaper, so that array should be fairly affordable. Might be time to look into making an array. Pcbs are dirt cheap.

 

I've been planning on using FEP film all along.

That vat could work for you if you don't mind it not being the same size as your screen. It could work for a 5.5" LCD, but it would be too small in all directions for an 8.9".

If you don't want to build a vat, look into the flex vat. They have a few different sizes. But again, it's not going to be a perfect fit for an LCD.