MOST Delta end effector for nylon: Difference between revisions

Print only in hood or well ventilated area.

BOM

• Lulzbot hexagon hotend $70 https://www.lulzbot.com/products/lulzbot-hexagon-hot-end
• 24V/4-5A power supply
• 3mm id x 6mm od PTFE tubing 630mm long
• 2x M6 x 0.8mm hex nut
• 3mm print effector
• 3mm extruder drive body
• ~1m 18ga speaker wire
• 2x ~1m 28ga twisted pair
• Heat shrink tubing

OpenSCAD design

• End effector - download latest version of Athena SCAD files and SCAD libraries. Change the Bowden dimensions in athena.scad. Render the end effector and print.
• Extruder drive - download latest version of extruder drive SCAD files (requires the SCAD library, as above). Change the filament dimensions in extruder_drive_renderer.scad. Render the extruder drive body and print.

Build Instructions

Testing with Athena RepRap 3D printer

10/22/15 - Test 0

Conditions

• Filament: Maxpower 333605 Residential Grade Round .105-Inch Trimmer Line 690-Foot Length from Amazon for $24.35/3 pounds (1.3kg $18.73/kg)
• End effector: 3mm Athena print effector
• Hot end: Lulzbot Hexagon, 3mm x 0.35mm
• Extruder drive: 3mm Phidias extruder drive
• Firmware: Franklin (latest)
• Temperature: 260 C
• Print speed: Variable (testing capabilities)
• Slicing: Cura 15.04 set to 3mm filament, 1 multiplier, 0.2mm layer height, print speed 70mm/s, 25% infill, 30mm/s initial layer speed
• Bed: Mirror with glue stick

Notes

1. Using a 12V fan on the end effector with pwm. Fan speed too high, end effector would not reach target temperature. Occluded lower half of fan with masking tape.
2. First layer too close to glass requiring decrease in speed.
3. Adjusted speed from 30% (21mm/s) to 140% (98mm/s) in 10% increments (70mm/s speed set in slicing) while printing first ~100 layers.
4. Lower layers exhibited poor interlayer bonding.
5. Print is flexible, but makes cracking noise when strained due to poor interlayer bonding.
6. Bridging performance improved when speed lowered to ~30mm/s
7. Experienced minor respiratory irritation during test. Future tests will be conducted under a hood.

10/23/15 - Test 1

Conditions

• Filament: Maxpower 333605 Residential Grade Round .105-Inch Trimmer Line 690-Foot Length from Amazon for $24.35/3 pounds (1.3kg $18.73/kg)
• End effector: 3mm Athena print effector
• Hot end: Lulzbot Hexagon, 3mm x 0.35mm
• Extruder drive: 3mm Phidias extruder drive
• Firmware: Franklin (latest)
• Temperature: 260 C
• Print speed: 70mm/s
• Slicing: Cura 15.04 set to 3mm filament, 1 multiplier, 0.2mm layer height, print speed 70mm/s, 25% infill, 30mm/s initial layer speed
• Bed: Mirror with glue stick

Notes

1. Using a 12V fan on the end effector with pwm. Fan speed too high, end effector would not reach target temperature. Occluded lower half of fan with masking tape.
2. Adjusted switch position (smaller) still some skipping on first layer
3. Bridging performance is abysmal. Cura doesn't help it.
4. Interlayer bonding improved.

10/23/15 - Test 2 ABORTED plugged nozzle

Conditions

• Filament: Maxpower 333605 Residential Grade Round .105-Inch Trimmer Line 690-Foot Length from Amazon for $24.35/3 pounds (1.3kg $18.73/kg)
• End effector: 3mm Athena print effector
• Hot end: Lulzbot Hexagon, 3mm x 0.35mm
• Extruder drive: 3mm Phidias extruder drive
• Firmware: Franklin (latest)
• Temperature: 265 C
• Print speed: 70mm/s
• Slicing: Slic3r 1.2.9, 2.667mm filament, 1 multiplier, 0.2mm layer height, print/infill.perimeter speed 70mm/s, bridge speed 30mm/s, 25% infill, 30mm/s initial layer speed
• Bed: Mirror with glue stick

Notes

1. Using a 12V fan on the end effector with pwm. Fan speed too high, end effector would not reach target temperature. Occluded lower half of fan with masking tape.

10/27/15 - Test 3

Conditions

• Filament: Maxpower 333605 Residential Grade Round .105-Inch Trimmer Line 690-Foot Length from Amazon for $24.35/3 pounds (1.3kg $18.73/kg)
• End effector: 3mm Athena print effector
• Hot end: Lulzbot Hexagon, 3mm x 0.35mm
• Extruder drive: 3mm Phidias extruder drive
• Firmware: Franklin (latest)
• Model: raptor_reloaded_gauntlet_supported.stl
• Temperature: 265 C
• Print speed: 70mm/s
• Slicing: Cura 15.04, 2.667mm filament, 1 multiplier, 0.2mm layer height, print/infill.perimeter speed 70mm/s, bridge speed 30mm/s, 10% infill, 30mm/s initial layer speed
• Bed: Mirror with glue stick

Notes

1. First print with 24V fan. Too much cooling, occluded fan with tape.
2. Part of print warped off of the bed.
3. Reduced print speed to 50% (35 mm/s max)
4. Reduced acceleration to 1000 mm.s^2
5. Reduced max speed to 100 mm/s

• Above done to counter end effector being dislodged during printing, which occurred on two previous attempts.

1. Print was brittle and broke easily at sides.

10/27/15 - Test 4

Conditions

• Filament: Maxpower 333605 Residential Grade Round .105-Inch Trimmer Line 690-Foot Length from Amazon for $24.35/3 pounds (1.3kg $18.73/kg)
• End effector: 3mm Athena print effector
• Hot end: Lulzbot Hexagon, 3mm x 0.35mm
• Extruder drive: 3mm Phidias extruder drive
• Firmware: Franklin (latest)
• Model: raptor_reloaded_gauntlet_supported.stl
• Temperature: 265 C
• Print speed: 45mm/s
• Slicing: Cura 15.04, 2.667mm filament, 1 multiplier, 0.2mm layer height, print/infill.perimeter speed 70mm/s, bridge speed 30mm/s, 10% infill, 30mm/s initial layer speed, raft with 0 air gap, support: touching build plate
• Bed: Mirror with glue stick

Notes

1. Printed with a raft having no air gap so print is fused to raft attempting to counter warping.
2. The mirror was cracked at startup and developed two more cracks during this print. The long crack through the center was also displaced in shear (see photo, above).
3. The raft tore off despite no air gap.
4. Overhang support was more difficult to remove. It was fused well to the underside of the print. Needle nose pliers were required to pull it off.

See also

• Weed wacker line as 3D printing filament
• MOST Delta end effector for polypropylene