JAP LCD Printer (Improved)

WORK IN PROGRESS Update 2019-05-05: Added 'Variants' section, filled 'BOM' section

Summary ====================

LCD printers become more and more popular as provide incredible printing quality and getting more and more affordable. LCD printer is a type of photo polymer printer - it cures resin with UV light layer by layer. UV light is masked with regular LCD matrix - black pixels displayed on LCD prevent resin above the pixels to cure.

One day I found JAP LCD 5.5 printer on internet. It looks pretty simple to build and set up. Studying its drawings and BOM I realized I already had number of parts, but they were slightly different from ones suggested by author. Additionally I was not happy with some of the technical decisions. So I decided to make an improved clone.

Basically this printer is a DIY analog of mass produced printers such as Wanhao Duplicator D7 or KLD-LCD1260, providing basically the same capabilities:

LCD resolution - 2560x1440
X-Y dot size - 47um
print area - 120x68mm
Z resolution - 10um

Differences with original JAP printer ====================

You can find original articles (Russian only, try using google translate) here:

Overall I tried to preserve original dimensions, as well as printed parts. Here is a brief list of my improvements:

Box and mechanics
- The only way to get the electronics compartment in the original design was a big hole at the bottom. I added a door instead
- Added a bottom plane with plenty of mounting holes
- Used MGN9 rails instead of 12mm shafts. Though shafts support is preserved, you can use either of them
Electronics
- Using Raspberry Pi instead of connecting printer to a computer via HDMI
- Used CNC Shield v4 + Arduino Nano instead of CNC Shield v3 and Arduino Uno
- Alternatively it is possible to use a Raspberry Pi shield specifically designed for LCD 3D printers.
- Added 16x2 LCD screen
- Using powerful MOSFET to drive LED instead of relay (which caused significant electical interferences)
Software
- Targeting to nanodlp software
- Use own arduino and nanodlp shield software

Variants ==================== I am still experimenting with various setups for a better print quality and printer stability.

Thus, initially I was using MGN9 rails for Z-axis because I had ones. Once I noticed that back side of the wooden carriage (the plate where MGN carriages are screwed to) is not super rigid. This caused some bending of the Z-carriage when moving up during printing. Although this did not impact printing quality I decided to try using 12mm shafts and flange linear bearings instead. I have not tested this new set up yet, so please stay tuned for an update.

Also I was using an arduino + cnc shield to drive the motor. This setup was somewhat buggy, arduino-raspberry communication failed randomly, it has a lot of wires and poor connections between components, and a few other issues. So I decided to develop my own nanodlp shield for RaspberryPi. See details here.

Perhaps Arduino-based setup could be tuned for a better stability, and wiring issues are also could be fixed with a cable management. But I just wanted to practice in developing RaspberryPI shields :) In any case I am describing both setups in this thing

Bill Of Materials ==================== Below is the list of materials and components that are currently used on my set up,

Materials:

Laset cut 6mm plywood (see DWG files in Files section)
PLA for printed parts
Some acrylic or glass-fiber laminate
aluninium self adhesive tape (it is just thin and non-transparent)
various thin and thick wires, e.g. awg26 for signal wires, 2x1.5mm2 or 3x1.5mm2 (or even 2.5mm2) wires for power lines and LED.

Harware stuff:

2 pcs 300mm MGN9 rails + 2 pcs MGN9H carriages
OR 2pcs 350mm 12mm shaft + 2 pcs LMK12LUU flange linear bearings
8mm diameter 300mm length 4mm pitch lead screw
2 nuts for the lead screw (I used POM nuts)
2 pcs 608zz bearings
60 pcs square M3 nuts for box assembly
60 pcs M3x15 screws
30+ pcs M3 locknuts + 30+ pcs M3 washers
30 more pcs M3 locknuts + 30 more pcs M3 washers if using MGN9 rails
30+ pcs M3x12 screws for mounting electronics (depends on how may stuff you want to mount)
20+ pcs M3x20, and 20+ pcs M3x25 screws (not really sure how many of them I used)
8 pcs M4x15 screws, 6 pcs M4x20 screws
2 pcs M4x70
2 pcs M4 wing nuts
10 pcs M4 locknuts
1 pcs M5x30, 2 pcs M5x50
A few M5 nuts and locknuts
2 pcs M5 wing nuts
1pcs M6x70, and 1 pcs M6x80 screws
a few M6 nuts and locknuts

Electronics:

Raspberry PI 3B+ or newer (Actually performance does not matter during printing, but important when you slice models using onboard slicer)
LS055R1SX04 5.5 inch 2560*1440 2K LCD Screen
HDMI controller for LCD screen (usually available in the same lot)
Protector glass for LCD screen
HDMI cable (There are different angled connectors available )
100W UV 405mn LED and a heatsink with a lens
150W Step-Up converter (pay attention it must have 'CC' or 'constant current' in its description, otherwise it is not suitable for driving LEDs)
12V 20A power supply
Populu Stepper Motor Driver (I used 'silent' TMC2100)
200mm Fan and 200mm fan grill
2 pcs 80mm fans
2x16 symbols LCD with I2C adapter
I2C level converter for the display
2 pcs 16mm push buttons (I used nice looing buttons with color LEDs inside)
An Up-Down button
Power socket

For an Arduino based setup you will also need:

Arduino Nano
CNC Shield V4
USB-MicroUSB cable
10-15A MOSFET module (I soldered my own with IRL2203 transistor)

Box assembly ====================

The box is made from laser cut 6mm plywood. In addition I sanded the surface with 400-800 grit paper and coated with couple layers of varnish. For parts assembly I used M3 screws and square nuts as well PVA glue.

Box assembly is pretty straightforward:

mount top, middle and bottom plates to side walls
mount front and back plates
there are 2 parts supporting bearings glued below top and middle plates

Carriage assembly:

Glue top and bottom horizontal plates
screw/glue vertical panels
screw/glue back panel
Screw linear bearings if you use shaft version

It is a good time to assembly anti-wobbling parts to the carriage as it will be quite tricky to do this later:

Print top and bottom anti-wobbling parts
Screw them with M3 screws
Install T8 nut - POM nut at the top, and brass one at the bottom.
Use 4 M3 screws for each nut. Check T8 lead screw moves freely, but without backlash, tighten screws if needed

TODOs ====================

The work is in progress. There are number of items to do.

Here is a reminder for myself:

upload final STLs and DXFs when ready
upload detail parts and assemblies pictures
describe assembly steps
Describe software set up

Let me know if you would like to join the project. Current work in progress sources are located at https://cad.onshape.com/documents/e9d65b07c23a08b13072c45e/w/5bea1c47c1cb98c3704fd181/e/c33ec5266769ab47ec768ee5

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