nanoDLP

mutsched

Member

Registered: 2018-10-27

Posts: 6

Need help with my diy LCD 15.6" 4K Printer

Hello to all my name is mutsched and i am 38 years old and from Austria. I build an LCD 460nm Resin printer for my exam in master for mechatronic. The frame is build, the electronic is ready and i try since 2 month to print any good result on my Printer. Software is nanodlp with nextion touch,Nema 23 with Ustepper encoder, 16x5m ballscrew,  15.6 4k Display and 200watt 460nm  led with 70 degree lenses on it and so on... (use daylight resin)

So my problem... When i make calibration print with new nanodlp software and i spread curing time from 2 to 10 seconds each 50ym layer i get fitting sizes from cube (STL and printed model) at time of 2.5 seconds each layer.

             So is that my perfect cure time ?

When i print another stl file like the benchy ship or the rook tower nothing works. Sometimse the model is broken in the middle or the half is in the printbed, or only the base layers are on the build plate.
Surface from the failed prints looks terrible. I will say it looks like wavy or something like else.

But calibration with those time settings looks great.

I use 3 base layers between 70 and 100ym and the 50ym layer between 2.5 and 3 seconds.

my moving speed is

Layers under 30: M650 D5 S1
Layers over 30: M650 D3 S5

Is S1 / 1mm/s to fast for peel move on Fet, flex vat?

So can anyone please help me to get my printer running ?? On 25 of februar i have exam and there i must show a printer that works. And i dont wont to show only calibration print...

A last question about calibration plate, is it right to meassure the cubes and when size fits thats the correct expose time for resin ?? Or is that wrong? or how i have to read calibration plate from nanodlp.
Could it be that the difference from base layer (70sec curing) to normal Layer(2.5sec) is to big ??

Sorry for so much questions at once but i am slowly desperate and my time to exam is running very fast.

Maybe anyone will be so nice and help me to fix my problem.
Thanks for all and best regards mutsched

Last edited by mutsched (2019-02-05 21:37:32)

mystamo

Member

Registered: 2019-01-23

Posts: 22

Re: Need help with my diy LCD 15.6" 4K Printer

Hey,

I'll quickly summarize what I did to get my new printer to start printing. Key points below.

1. Make sure your FEP is well stretched onto the Vat. It should sound like a very tingy drum. (Tingy - High frequency)
2. Run a few tests to find a good layer cure time and a good print adhesion layer time.
2a. Using a piece of FEP. put it flat against the LCD. pour a little bit of resin onto the surface and try to make it flat. Expose a layer. Something simple like a circular disk. My exposure times for a layer is about 10 seconds. Anything less and the layer comes off in bits and parts. Anything more and the layer gets stiff and thick. This is your normal layer exposure time. Remove layers using a tweezer until you find the optimal time.
2b. Using the FEP vat. Pour some resin and lower the build surface. The build surface should be calibrated prior with a sheet of paper. The paper should barely slip out from under the screen and build plate. Once you put your vat. The thickness of the FEP sheet will cover the distance between the LCD and build plate. Lower the build plate and expose a layer for 90-200s. The layer cycle the build plate up then down. 4mm lift is what I do. LISTEN TO THE SOUND. it will POP off the vat surface and hopefully stick to your build plate. When you find the optimal time. You will have good adhesion to the build plate. Nice stiff first layers and it will come off the vat easily. I use 2 base layers for my setup at 140s each exposure. Frequently raise the bed up  tests and look to ensure the layers have properly come off the vat surface. They should be on the plate.
3. Execute a print with your new settings.
4. The first 2 layers should stick no problem. The normal layer build layers should make a small pop sound as well. Sounds are very important when printing. Listen to the pop sound inbetween every layer. Also watch how the resin raises then suddenly falls as the surface tension releases from the vat surface lifting up while trying to remove the exposed layer.
5. Lastly. Layer heights. If your model is starting out ok. Then falling apart. Check your Z calibration for steps. Then check your layer heights. Exposure vs layer height are related. So if you make bigger layers. You need to expose for longer. I expose both normal and first layers at 50um. I suggest you try the same.

Mine :

2 Layers 140s
Remaining layers at 10s.
Slow speeds on first 2mm of print. (VERY SLOW).
50um layers

Again the key take aways are. Proper bed calibration. Then timing calibration . Then test prints. I would stay stick with printing the Maker Rook for a while till you get a print.

Mo

mutsched

Member

Registered: 2018-10-27

Posts: 6

Re: Need help with my diy LCD 15.6" 4K Printer

Thanks
In the meantime i found other problems to solve...

I have my backlight LED controlled over GPIO12 ( with shutter controll command) on RPI and motor control over arduino.

So now after move is complete my led turns on ( because of shutter open before each layer) and then the image is shown.
I want some time so that the resin can settle down for about 5 seconds.
When i add "wait before print" time the only thing that changes is that the image will show after 5 sec BUT the led(shutter control) turns on after move is complete.

So thats wasting energy and my comple vat hardens slowly during print..

Is there any possibility to change that ?? Is there any command in Gbox to control GPIO on rpi ?? Or how cn i fix my problem. ??

maybe someone knows a solution...

oliveenchine

Member

Registered: 2016-03-11

Posts: 26

Re: Need help with my diy LCD 15.6" 4K Printer

I had same issue,

the solution is to use GpioHigh xx/ GpioLow xx in you Gcode box instead of using the shutter function.

Thanks
In the meantime i found other problems to solve...

I have my backlight LED controlled over GPIO12 ( with shutter controll command) on RPI and motor control over arduino.

So now after move is complete my led turns on ( because of shutter open before each layer) and then the image is shown.
I want some time so that the resin can settle down for about 5 seconds.
When i add "wait before print" time the only thing that changes is that the image will show after 5 sec BUT the led(shutter control) turns on after move is complete.

So thats wasting energy and my comple vat hardens slowly during print..

Is there any possibility to change that ?? Is there any command in Gbox to control GPIO on rpi ?? Or how cn i fix my problem. ??

maybe someone knows a solution...

mutsched

Member

Registered: 2018-10-27

Posts: 6

Re: Need help with my diy LCD 15.6" 4K Printer

Hello oliveenchine
thanks for your answer.

I search the internet about your recommendation but i found no solution.

Here is my gcode before each layer:

M650 D{([[LayerNumber]]<50)*2+5} S{0.6-(([[LayerNumber]]<70)*0.3)}
M651
G4 P5000
G1 Z[[LayerPosition]]
[[WaitForDoneMessage]]
M114
[[PositionSet [[LayerPosition]]]]

Code after each layer:
[[PositionChange [[ZLiftDistance]]]]

The cde boxes for shutter open and shutter closed are empty.
And my shutter is controlled from the Shutter GPIO setting in the machine setup page.

The command is : Physical 7, BCM 4 (Pin for shutter on outputpins from raspberry)

The movement and the endtop icntrolled over serial communication to Taurino with prototyp shield and the on ustepper boards n my stepper.

So my question: Where i have to put what command to make it work

I want that the Build plate moves up, build plate wait, build plate moves down to next layer, WAIT 5 SEC TO OPEN SHUTTER, turn on Shutter( in y case led array) and show the image at same time like shutter open. ?

Maybe you can show me your settings ??

Thanks and best regards