I think we have to reliably enable hobby-class machines first. Now, some people take hobby pretty far and I'm not trying to cap this off too small, I just don't want to boil the oceans. I'd say if we can do a bit more than what CRAMPS can do today, we should.
Personally, I'd want to at least be able to handle the larger 3D printers, smaller CNC mills and some pick-and-place machines. Looking around for some open source ones where the controller could be swapped: * Aleph Objects LulzBot Tax Pro * SeeMeCNC Rostock Max v3 * PocketNC V2 * Charmhigh CHM-T36VA (not open source, but affordable and hackable) * Lasersaur The desire for the above is mostly to be a vehicle for demonstrating motion control in a familiar way. Something CRAMPS-like could largely serve the above, though would need to be done regarding the price to make it sufficiently attractive, perhaps bundling as a kit. Getting to the standard DB25 seems like a required thing to be widely usable in the community, no? This all said, I think handling BLDC motors or even small AC motors with encoders and adding software motor control functions would be fantastic and would give some important examples to the community. What I need to try to understand the requirements are examples like the above. Then we can add up all the I/Os, required currents/voltages, look at the encoder protocols, etc. and arrive at a sane set of compromises. If I go look around a place like https://openbuildspartstore.com/openbuilds-c-beam-machine/, it seems all their machines use steppers. Looking around https://odriverobotics.com/, perhaps this stuff just hasn't become popular with hobbyists yet? Can we get a sane set of requirements on what motors we need to drive and encoders we need to support? Are hobby motors like https://hobbyking.com/en_us/9235-100kv-turnigy-multistar-brushless-multi-rotor-motor.html really available in a steady supply (I've had issues with this in my quadcopters)? If there was a solution for 48V BLDC motors w/ encoders, would people start building something or am I just missing where all these machines are already? (Help me find them.) Would it use something like http://www.machinekit.io/docs/man/man9/bldc_hall3v2/ or something else? /me reads https://www.reddit.com/r/AskEngineers/comments/4qx9b0/why_arent_brushless_dc_motors_more_commonly_used/ Man, I think I'm about to step in an ants nest wondering about BLDC vs. why not just control AC servo motors, but why not? Looking around for some decision factors on motor type support, I found an add for the ClearPath motors that clarified some things for me: https://www.youtube.com/watch?v=zUy89MT_Rkk. Looking around a bit more, I found on this discussion form a message where Rick Mann got those ClearPath motors working with his BeagleBone. Anyway, I'd expect there to be a sweet spot for a motor power range and amount of integration suitable to be covered, though perhaps we are talking about needing 2-3 cape designs to be available based on how different some requirements are? Is there real value in providing just the DB25? Once I can gather a bit more feedback, I'll come up with a good mechanism for a survey. I'm really looking for those open hardware examples sitting at higher power than the examples I gave that are nicely handled by steppers. On Tue, Mar 17, 2020 at 11:31 PM Charles Steinkuehler < char...@steinkuehler.net> wrote: > This depends a lot on what sort of machine you're trying to drive. A > "standard" CNC machine with step/dir typically needs a DB25 (aka: > parallel port) with buffered signals you can connect to external stepper > drivers. A 3D printer would more typically have low-powered "Pololu" > style drivers either on-board or via sockets along with some high power > outputs for the extruder and bed heaters. A more advanced system might > provide a control signal (+/- 10V, or perhaps PWM) to drive a motor > driver and provide for encoder feedback to close the servo loop. > > ...so it really depends on what sort of system(s) you want to support, > and how much you want to try to be a "one size fits all" solution. > > On 3/12/2020 8:38 AM, Jason Kridner wrote: > > Seeed is looking to not only build a Machinekit-focused Cape for > BeagleBone > > Black and BeagleBone AI, but to: > > * Take in features and feedback from the community > > * Contribute the design to open source and certify it as such > > * Manufacture the design under the BeagleBoard.org name to support the > > BeagleBoard.org Foundation and community > > * Help assemble and provide software images configured for an open source > > 3D printer and CNC machine (with BeagleBoard.org and community guidance > and > > support) > > * Offer a collection of additional accessories which might commonly be > > needed > > > > I am very excited about this because I know Seeed cares about open > hardware > > and also knows how to deliver solutions reliably and cost effectively. > > > > So, what are your ideas about where to start on such a cape? > > > > -- > Charles Steinkuehler > char...@steinkuehler.net > -- https://beagleboard.org/about -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. 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