Tobben's quick first comments:
- 1 day
This is then the major hurdle to overcome. It is clear and measurable, and we do it for economical reasons, so I like it.
- Auto bed level
Increases usability tremendously. Off the shelf solutions exist.
- OSHWA compliant, Respects Your Freedom certified
OSHWA compliant is no problems. Respects Your Freedom-certification might require us to apply and might take some time? Would help win the confidence of like-minded potential contributors. Process of getting verification described here: libreplanet
- $500 in parts for single head
We will trade away "cheapness" for more "reliability" and "ease of build", so I think 500 a good limit.
- Wireless to allow for freeing up computer
Freeing up computer is best done like this: upload gcode to SD card. Initiate SD print. Wireless connection to printer frees user from having to use a cable when uploading file and initiating print.
Requiring SD capability would be reasonable. There are off the shelf solutions available both for wireless and SD.
- Rubber print capable, without head exchange (critical for OSE gaskets, rubber washers and o-rings in low and high pressure hydraulics and pneumatics)
This would mean a no-Bowden filament feed. I agree.
- Multiple print head addable, up to 4 for practical considerations
- Addable clear enclosure
These are two upgrades/add-ons. Implies that the printer should be easily upgradable. All RepRaps I've seen have been upgraded by their owners, sometimes in really unpredictable ways, so preparing for this is clearly the way to go. Designing for add ons also helps keeping workshop short.
Would designing the clear enclosure and the quadruple print head mount be included in Master's work? Maybe it will be better to formulate add-ons as goals. Also, we will have much more information about what add-ons participants want after the first workshop. Asking them what add-ons they find interesting would be a nice way to involve them.
- Meets or exceeds reliability of Lulzbot
Reliability is of course important and as an engineer you have a "feel" for it. How would we go about measuring it?
- XY-fixed build platform
This will increase price, build time and printer volume because the printer will be top heavy and require a rigid frame. I suggest we limit build volume to < 8000 cm3 or use a stronger Y-motor instead of requiring XY-fixed build platform. (The third option, to limit Y-speed, would definitely frustrate owners.)
Insisting on XY-fixed build platform will drive us towards one of the following basic designs: http://smartfriendz.com/en/home/54-smartrapcore-alu-2597462281828.html http://www.morgan3dp.com/store/#!/Morgan-Mega/p/50319237/category=0 http://www.appropedia.org/Athena_Build_Overview
- Unheated build platform
Helps keep workshop short.
- Self-harvesting for mass production part capacity
This needs to be more specific. 3d printed parts should be used where its reasonable. Stepper motors, electronics, bearings, screws and nuts probably won't be self harvested.
Designing from flat sheets of material (wood, mdf, steel, aluminium) is way more frequent in 3d printer designs, since cutting is so much faster and easier than FFF printing. If we give the printer a laser cutter tool head upgrade, it will increase its ability to effectively self-harvest. If we make the printer strong enough, we can also give it CNC tool head upgrade.
I think "ease of part sourcing" and "produce-able with OSHW machines" are both more achievable and more relevant than "self replication".
- Future: works.with irregular-dimension filament?
Would be a significant contribution to the RepRap community. Filament diameter sensors and versions of Marlin (firmware) that works with them have already been made (no open source though)
- CC-BY-NC by flipper CC-BY-NC-SA by imitation idea stage. Discussions with optics researcher at the physics institution has led me to believe that the optical web cam sensor approach would be a good first try (cheap, non-invasive, accurate enough).
- Functional Logic and design rationale is fully documented
- conductive metal print capable for Cordless Tool Construction Set
Maybe an upgrade for later? Printing conductive metal will be too much work for including in Master's.