Cerealbot/Hardware
Contents
[hide]Hardware Configuration
Modified HBP
Heated Build Platform:
Wire sockets 2-3: 5.6 Ohm
Wire sockets 1-2 & 1-3: 2.8 Ohm
1-2 and 1-3 are in parallel, so their equivalent resistance is actually 1.4 Ohm.
V=IR -> I=V/R
24V @ 2.8 Ohm: I=8.6A, P=206W
24V @ 5.6 Ohm: I=4.3A, P=103W
24V @ 1.4 Ohm: I=17A, P=408W
12V @ 2.8 Ohm: I=4.3A, P=51W
12V @ 5.6 Ohm: I=2.2A, P=26W
12V @ 1.4 Ohm: I=8.6A, P=103W
My 24V PSU is rated to 14A. The 12V PSU is rated to 30A. I'm currently using the 408W connection, and haven't blown up the PSU... yet.
Dimensions:
PCB: 1.65mm by 200x200mm
Glass: 3.2mm by 200x200mm
Aluminum: 3.5mm by ~230x~165mm
Part Detachment
Pop-Bar
The pop-bar is a system which minimizes effort to ensure release of a part from the print bed. Currently in use.
Pivot-Plate
The pivot-plate is a simplified design compared to the pop-bar, but raises some difficult design and construction questions.
The system works on a very basic principle: flexing the build plate will detach a part. Since the build plate is aluminum and not feasible to flex, the plate will be divided in two and hinged, so that it will pivot to force the part off. I hope to design such that a standard servo can be used, otherwise a worm drive and stepper motor system will be investigated.
The design also needs to consider the heating plate mounted below, which means that the heater needs to be modified or the bed can only lift upwards.
Current
- Killswitch, both remote and local
Planned
Immediate:
- Detect use of emg stop button in arduino
- Pop-bar and channel
- servo structure
- Removal arm. Can also double as print surface cleaner?
- New GT2 belt mount for print bed
Later:
- Just melt failed prints from the printhead? Then clean with silicon sponge?
- Use accelerometer to detect grinding gears/belts?
- larger print surface to maximize hotplate use
- Longer steel rods
- more GT2 belt
- Print a GT2 belt clip? Zipties suck
- Better webcamera setup
- different embedded computer?
- Filament absence sensor
- Just look for the circuit completion when the extruder rollers connect?
- Birdsnest detection
- Print adhesion detection
- General failure detection
- Detect belt slipping?
- Use linear encoders? I mean, they really ought to be standard on a 3d printer.
- Heater dead-mans switch
- Ping the webpage?
- snoop on gcode over serial?
X-Y Axis Upgrade:
- The printer comes with 8mm rods for the x-y axis. 250mm and 268mm in length.
- Longer rods available on Amazon.
- Also available from CNCsuperstore
- 300mm shafts are ideal for the 12" plates available from Speedymetals.com
- Build plates for x-y upgrade:
