To create this machine, new software and a new mechanical set up is required. 3 more stepper motors, 3 more GT2 belts and a controller board that can utilize LinuxCNC as well as completely revamped corner brackets to hold the machine together. I have high hopes for this machine one day, but software needs to catch up first.
Saturday, May 24, 2014
MK-XH
The next iteration in the Mega Kossel X line down the road is the H version for Hexapod. This machine is extremely experimental, and considered to be bleeding edge. Instead of a standard Delta 3D printer with 3 columns and 3 carriages that use delta kinematics to keep the effector level for prints. The hexapod instead uses 6 columns and 6 carriages each one controlling one of the 6 diagonal rods attached to the effector. This allows for the effector to be be controlled by pitch,yaw and roll. This means that the effector and its attachment can now print at angles and over uneven surfaces.
Thursday, May 8, 2014
Pellet Bowden Extruder System for Delta printers
There hasn't been too much recent research in direct pellet Bowden drive and this may be a missed opportunity. Specifically for delta printers, I feel like we aren't maximizing the vertical space that deltas have which consumer Cartesian machines do not.
Cartesian machines typically use direct drive extruders while 99% of deltas use a Bowden system. Research in direct filament extruders from pellets have proven to be far too large, heavy and unwieldy to use with retraction issues.
To install a filament extruder to a Bowden system in a machine such as an ultimaker takes considerable modification above the system and is seemingly impossible to mount on the frame itself staying within frame dimensions.
However, I believe we can utilize the space above the effector and stay within reasonable dimensional constraints for larger delta machines.
The most common filament extruder today is the Lyman filament extruder which the designs can be found on thingiverse. It's large, heavy, and a horizontal extruder.
There was research done with makibox ramen pellet extruder last seen Q4 of 2012 loading pellets in a linear fashion, but nothing has come to fruition.
The current hot end design is well established and wide spread and thus keeping that in place for the Bowden Is essential for ease of adoption at this time.
With that being said, the focus of current filament extruders is speed to be spooled up. This mean very long auger screws are used to transport as many pellets to the heated orifice as possible. This requires very high torque from a windshield wiper usually.
I hope to replace this long auger screw with a much shorter one pushing less pellets through as we do not need filament delivered that quickly ( only a theory, research and experimentation required) or just a standard screw. This would imply less necessary torque, so that we can possibly use a geared stepper to drive the rotation. This is an important note that we are using this motor.
Using a stepper motor allows us to directly integrate control to already established controller boards as a second extruder. However with this current design theory, retraction is not possible as pellets are continually fed down to the heating end of the filament extruder. This means our current standard extruder will probably be necessary to control retraction and extrusion to the printing hot end. With the filament extruder motor being seen as a second extruder. I theorize that we may be able to synchronize both extruders. One to stop filament production and the other for retraction.
Hopper -> screw driven by stepper motor -> Heating element -> 1.75mm diameter die -> Extrusion (cooled?) -> filament detector via mechanical endstop switch -> Main extruder -> bowden tube -> hotend
More research and experimentation is necessary in:
-If stepper motor is a viable replacement to the windshield motor
-Temp of plastic extrusion and how soft/ solid the plastic immediately after pellet to filament extrusion point
-Whether or not cooling is necessary prior to main extruder to retain rigid shape, if so, how much cooling? Direct fan cooling, tube directed blower fan across the the extruded filament
-Temp of hot end required to print the fresh filament as the filament will be soft/warm/hot?
This could very well lead to developments in directing masterbatch pellets to allow for full color printing. As I continue my research and development, this may very well fail or not, but I would really like just to facilitate discussion about this topic.
Cartesian machines typically use direct drive extruders while 99% of deltas use a Bowden system. Research in direct filament extruders from pellets have proven to be far too large, heavy and unwieldy to use with retraction issues.
To install a filament extruder to a Bowden system in a machine such as an ultimaker takes considerable modification above the system and is seemingly impossible to mount on the frame itself staying within frame dimensions.
However, I believe we can utilize the space above the effector and stay within reasonable dimensional constraints for larger delta machines.
The most common filament extruder today is the Lyman filament extruder which the designs can be found on thingiverse. It's large, heavy, and a horizontal extruder.
There was research done with makibox ramen pellet extruder last seen Q4 of 2012 loading pellets in a linear fashion, but nothing has come to fruition.
The current hot end design is well established and wide spread and thus keeping that in place for the Bowden Is essential for ease of adoption at this time.
With that being said, the focus of current filament extruders is speed to be spooled up. This mean very long auger screws are used to transport as many pellets to the heated orifice as possible. This requires very high torque from a windshield wiper usually.
I hope to replace this long auger screw with a much shorter one pushing less pellets through as we do not need filament delivered that quickly ( only a theory, research and experimentation required) or just a standard screw. This would imply less necessary torque, so that we can possibly use a geared stepper to drive the rotation. This is an important note that we are using this motor.
Using a stepper motor allows us to directly integrate control to already established controller boards as a second extruder. However with this current design theory, retraction is not possible as pellets are continually fed down to the heating end of the filament extruder. This means our current standard extruder will probably be necessary to control retraction and extrusion to the printing hot end. With the filament extruder motor being seen as a second extruder. I theorize that we may be able to synchronize both extruders. One to stop filament production and the other for retraction.
Hopper -> screw driven by stepper motor -> Heating element -> 1.75mm diameter die -> Extrusion (cooled?) -> filament detector via mechanical endstop switch -> Main extruder -> bowden tube -> hotend
More research and experimentation is necessary in:
-If stepper motor is a viable replacement to the windshield motor
-Temp of plastic extrusion and how soft/ solid the plastic immediately after pellet to filament extrusion point
-Whether or not cooling is necessary prior to main extruder to retain rigid shape, if so, how much cooling? Direct fan cooling, tube directed blower fan across the the extruded filament
-Temp of hot end required to print the fresh filament as the filament will be soft/warm/hot?
This could very well lead to developments in directing masterbatch pellets to allow for full color printing. As I continue my research and development, this may very well fail or not, but I would really like just to facilitate discussion about this topic.
Wednesday, May 7, 2014
First Post
The very first post of my 3D printing research and experimentation blog. Here, I will further document my research and experiments for FFF (Fused Filament Fabrication) specializing in the alternate builds of 3D printer, mainly the Delta-style printer.
As for my delta printer, I am in the process of building my MK-X0 (Mega Kossel X Zero) derived from Johann Rochell's Kossel Mini design. How it differs from the basic design:
- 1000mm tall extrusions / 485mm horizontal 20/20 black anodized extrusions
- Wheel carriages (possibly rails)
- Custom effector
- Griffin 3D printer Diagonal Rods
- Automated Tool Changing via tool magnetic mounts on the effector
- Vertical cross bracing 500mm 20/20 black anodized extrusions
- Tool Mounts on the X-braces
- Multi-Cylindrical Tool (Pencil, Pen, X-acto Knife, Sharpie)
- Wood Burner tool
- PCB engraver
- Experimental: Pellet Bowden Tube Drive
- Heated Build Chamber
- Acrylic Enclosure (Experimental: adjustable oven bag only within print volume) [M X K branding on the acrylic enclosure]
- Out of filament detector
- Built-in Octopi
- NFC tag Octoprint
- Led lights mounted to the ceiling
- Extruder and filament roll built into top of printer
- FSR Bed Leveling
- Local and Remote on/off switch
- Astroyn Dampers
- 400mm Boroscillate Glass
- Cork/Acrylic heat insulation for the build plate
- Sound Insulation
- Magnetic Build plate
- 15MP Webcam to monitor prints via Octoprint / Photogrammetry on the effector
- Experimental: Using a turntable under the glass print bed and laser in conjunction with webcam for scanning capabilities built in.
Other Technical Specs:
- 16-tooth Pulley for Torque
- 1/16 Microstepping
- RAMPS 1.4 (Possibly Azteeg X5 in the future)
- GADGETS3D LCD screen
- 650 Watt ATX PSU
- NEMA17 86-oz. in holding Torque
- Extrusions are from Misumi
- MK-V J-Head .4mm
- 1.75 Filament
- 350mm x 435mm print area
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