Multi material printer
Posted by leadinglights
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Multi material printer June 16, 2015 12:15PM |
For about a year I have been working on a multi-material printer. After several derailments I can begin to see the light at the end of the tunnel and the need to get my teeth into the software is becoming apparent. My general idea is to have the build stage moving in both X and Y thus making the mass of the extruders relatively unimportant.
The moving XY table can be seen at [www.youtube.com]
The general method of operation is that the active hotend is moved to a datum position while all unselected hotends are moved away from the datum and lifted (by about 1mm).
At present there are 5 hot-ends and extruders spaced 20mm apart along an axis parallel to the X axis. Two of the extruders are close coupled to their respective hot-ends while three are coupled by short bowden tubes of about 200mm length. Changing the hot end is accomplished by lifting the currently selected hot-end from the datum position and sliding the entire set of hot-ends until the newly selected one is at the datum position at which point the solenoid is de-energised lowering the hot-end into the printing position.
Carriage with 5 hot-ends, including two close coupled ones and the lift solenoid.
The control is intended to be by a separate microcontroller and 6 Pololu or Stepstick drivers along with a power transistor to drive the lift solenoid. Communication from the Atmega 2560/RAMPS board set will cause the hot-end change as detailed above and a signal will be sent back to the Atmega on successful completion of the change so that the XYZ motion can continue.
The drawing omits such things as the limit switches, heaters etc., for clarity.
The status to date is that the XY mechanism works well, 5 extruders and parts of the extruder carriage are made along with the watercooling system for the cold end of the hot-end. Still to be done is the Z carriage, the solenoid lift mechanism and a redesign of the heater part of the hot-end The hardware and particularly the software for the extruder controller and even the firmware on which to base the main controller are still undecided and undesigned.
I need to get a signal from the Atmega to an ancillary (PIC) PCB that a hot-end change is required, holding all XYZ motion until the change had been accomplished. Signals to run the extruder motors will probably be through the same communication link although a hardware kludge - diverting the step & direction signals from the RAMPS board with enable from the PIC board should also be possible.
The actual driving of the hot-ends is within my abilities - and I am looking forward to coding again after many years, preferably in PIC assembler in which I have written many stepper and brushless DC motor programs. The reason for my reluctance to enter into new high level languages is that I am no longer young - having missed WWII but only a few months.
Mike
The moving XY table can be seen at [www.youtube.com]
The general method of operation is that the active hotend is moved to a datum position while all unselected hotends are moved away from the datum and lifted (by about 1mm).
At present there are 5 hot-ends and extruders spaced 20mm apart along an axis parallel to the X axis. Two of the extruders are close coupled to their respective hot-ends while three are coupled by short bowden tubes of about 200mm length. Changing the hot end is accomplished by lifting the currently selected hot-end from the datum position and sliding the entire set of hot-ends until the newly selected one is at the datum position at which point the solenoid is de-energised lowering the hot-end into the printing position.
Carriage with 5 hot-ends, including two close coupled ones and the lift solenoid.
The control is intended to be by a separate microcontroller and 6 Pololu or Stepstick drivers along with a power transistor to drive the lift solenoid. Communication from the Atmega 2560/RAMPS board set will cause the hot-end change as detailed above and a signal will be sent back to the Atmega on successful completion of the change so that the XYZ motion can continue.
The drawing omits such things as the limit switches, heaters etc., for clarity.
The status to date is that the XY mechanism works well, 5 extruders and parts of the extruder carriage are made along with the watercooling system for the cold end of the hot-end. Still to be done is the Z carriage, the solenoid lift mechanism and a redesign of the heater part of the hot-end The hardware and particularly the software for the extruder controller and even the firmware on which to base the main controller are still undecided and undesigned.
I need to get a signal from the Atmega to an ancillary (PIC) PCB that a hot-end change is required, holding all XYZ motion until the change had been accomplished. Signals to run the extruder motors will probably be through the same communication link although a hardware kludge - diverting the step & direction signals from the RAMPS board with enable from the PIC board should also be possible.
The actual driving of the hot-ends is within my abilities - and I am looking forward to coding again after many years, preferably in PIC assembler in which I have written many stepper and brushless DC motor programs. The reason for my reluctance to enter into new high level languages is that I am no longer young - having missed WWII but only a few months.
Mike
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