Dr4ωb@c_k_ (tem, nikl, jakob)

Alternative Names

• Drawback
• Pencil Punk
• HacksyDraw

Requirements

• size for painting a3 paper
• capstan drive
• h bot for movement
• easily to assemble / disassemble
  • removable thread of the capstan drive

Roadmap

Syntax: 1, 2, 1.1
- task 1 and 2 are independent from each other
- task 1.1 can only be executed after task 1

• 1 cad & assemble all parts
• 1.1 print parts (until friday ev)
• 2 power electronics
  • 2.1 user interface (svg to motor control code)
• 3 toolpath planning: svg in -> toolpath out
• 100 make video

availability friday

• matthias 9 bis 14.30, ab 18.00
• niklas 15.00 bis ...
• jakob ab 10.00

next steps

• friday 12.00: all single parts modeled
• friday 15.00: all parts assembled (the other person does driver)

References

• https://github.com/SeanP2001/Urumbu_USB_Stepper_Motor
• cable carriers 3d printable
• urumbu further work
• sampo
• OSAP web framework for talking with usb-driven hardware modules (e.g. motors), shoving everything you would make on pcbs onto the desktop for rapid prototyping. overkill for our project.
• capston drive

Mechanical Design

• TODO insert niclas' sketches

BOM

take 3d models from urumbot

model in cad or find 3d models from somewher else, e.g. from here

probabably easy to get

1. v-bearing (5x)
2. capstan (2x) (take from urumbot)
3. idler (2x) (take from urumbot) 7.1) extrusion vertical (1x) 7.2) extrusion horizontal (1x)
4. stepper motor (2x)
5. wire (1x)

probably model ourselfs

3. extrusion cap (1x)
4. sledge + assemble it (2x)
5. extrusion cap head (1x)

do not model

5. motor enclosure right (1x) (DEPRECATED)
6. motor enclosure left (1x) (DEPRECATED)
7. sledge case (1x) (DEPRECATED)

todo

• redraw
  • extrusion cap + v bearing
  • sledge with + v bearing
  • motors

todo (jakob)

• capstan drive urumbot durchlesen

design changes

• removing 9 to place v bearings on same level as vertical extrusion
• to do that we have to put v bearings at the end of the extrusion caps
• do not use motor end caps but use metal or 3d printed plastic caps. ask ferdi, maybe also acrylic

Motor Driver

• https://www.digikey.com/en/products/detail/texas-instruments/DRV8428PWPR/13563046
• not in the lab. ordered
• alternative: hbot firmware together with ramps
• we fonud those at the 3d printer in the hackspace: https://www.allegromicro.com/~/media/Files/Datasheets/A4988-Datasheet.ashx
• can you use different stepper drivers in one project?

Toolpaths

• gcode to motor action
• urumbu uses https://github.com/SeanP2001/Urumbu_USB_Stepper_Motor
• if urumbu is used, use sampo stuff: https://gitlab.com/fab-lab-oulu/sampo