This project is an attempt to build a unique experimental 3D printer with these specific goals:
- it should be compact. Large bed with long printing time 24++ hr is really not practical (for DIY) and bigger mechanic leads to a harder tuning process.
- it should focus on PLA / PVA dual non bowden extruder. The pressure and hysteresis in the bowden tube is hard to predict and this project aim to avoid that headache. PLA/PVA is the only way for FDM printer to produce literally any geometry
- it should uses no custom CNC parts to build the printer. Anyone with access to 3D printer should be able to build this printer. As a result there will be a lot of Openbuilds parts....
[6/30/17] - Y Z and X partially assembled, missing one more Z tower
[7/13/17] - finished overall assembly
This section saved for Y axis development:
Prusa i3 arguably has the most common 3D printing bed size. well I find that I actually very rarely print at that size. most of my print actually fit in my palm size. So, the C-Beam Gantry Plate - XLarge seem to be the perfect fit and thus this Y bed is design around this plate.
I also want the bed to be removable for those low print that could be difficult to remove. the use of double XLarge allow the top plate to be removed by M5x8 screw there are 4 M5 tapped holes on the plate.
The recommended print surface is Zebra skin from Printinz. This has been tested for durability and I like it very much. Blue painter tape is too easy to rip.
See yup this is big enough
This section saved for X axis development:
The x carriage will be moving fast and rapid in an overhang arm. So, weight will be a factor. I have tried bowden and had some success but my conclusion is avoid if possible. I know adding direct motor to the x carriage will have severe impact on X travel speed so I came up with a way to separate the Motor from hotend but still in the same axis; it's a parallel X arm connected to the same Z carriage
Here's my initial sketch:
Followed by rendering
Belt x axis length 780mm give or take. path shown below
This section saved for Z axis development:
The z tower uses the stock openbuilds nema 17 lead screw actuator as base design. I modified the motor placement to the side to save space so it doesn't protrude beyond the top of the printer. This is a good opportunity to use reduction pulley. I have chosen to use 40teeth and 20teeth reduction. With a regular 1.8deg motor, this will increase the Z resolution of Tr8*8 lead screw to a factor of 0.02mm per full step so the optimal z layer height for printing would be in a factor of 20 micron
I don't recommend the use of 0.9deg to drive the Z axis. the overhang arm carrying all that X component perhaps would be too heavy given that generally 0.9deg will have a lower torque than 1.8deg. Plus there really isn't any practical benefit of the increase in resolution 0.9deg motor can offer since we already get good resolution with combination of 1.8deg and pulley reduction
This arrangement yield printable volume of 125 x 125 x 150mm
3D printer with 7 drivers, compact, dual extruder, no CNC part. All Openbuilds and 3D printed part. This is purely experimental.
- Build License:
- CC - Attribution NonCommercial - Share Alike - CC BY NC SA
Reason for this Buildto have fun
Inspired byIndie I2, Bukito and all other crane style 3d printer that I don't remember the name