I’m designing/building a custom 3D printer (just for fun) and this topic has far and away been the most frustrating to dig into. I’m a mechanical engineer by trade so I’m reasonably comfortable with the mechanical aspects of the printer but I’m weak on the electronics side of things and my only printer-building experience prior to this was buying a Prusa i3 mk2s kit earlier this year and installing the components on a frame/layout of my own design.
I’ve been unable to find a good online resource (or a few) to get educated on control boards and this frustrates me to no end. Information seems to be all over the place and in some cases is contradictory. There are very few reviews of “higher end” boards and those that exist are far from scientific/unbiased. I’ve also been unable to find good technical resources that explain the tech specs of the board in a useful way for a non electrical engineer. If any of these things aren’t true please educate me so I can educate myself!
I’m using Wantai NEMA17 steppers that are 2.4A and 0.9 degrees/step (part number is 42BYGHM810 and I’ve already purchased them). I want to implement some level of microstepping but in the end the capability of the motors I’ve selected combined with the machine design/layout/masses may limit the amount of microstepping I can do. I also expect to push the motors pretty hard with respect to RPM. Given both of these things and the fact that I’m using 400 steps/rot motors I’ve decided to go with a 32-bit ARM processor based board. I’ve found references to a bunch of different boards but I’d say the four most common boards I’ve seen mentioned are Smoothieboard, Duet, Beaglebone, and the Azteeg X5.
I should also note I have a single extruder (but want to have the capability to add a second one later), and have three steppers for X, Y, and Z motion. I also have a 1200W 110VAC heated bed that I want to drive “external” to the controller via a solid state relay (so the board has to actuate the relay but does not have to pass the power). I’m using a 24VDC general bus for my hotend, fans, and steppers. My current thoughts/impressions of these boards:
Azteeg X5 GT - I’m a little confused that this seems to be a board forked from the smoothie project that runs on smoothieware but either way, the online reviews are mixed (like all the boards). It seems to have nearly the same capability as the smoothieboard but the fact that I can get it bundled with 5x Bigfoot BSD2660 drivers (based on TMC2660) caught my eye. It also seems like it’ll be a little cheaper than the smoothieboard. Currently I think this is my #1 choice but again, I have no idea what I’m doing.
Smoothieboard - same deal as above, lots of lovers and lots of haters on the internet. My impression is the board is solidly made and the firmware has come a long way over the last year or so but it’s expensive and still lacks some of the safety and “nice to have” features found in other firmware packages like Marlin. It also seems like I will have to go with external stepper drivers since getting the most out of my motors will drive current over the 2A max for the built-in drivers. The only thing more convoluted and confusing to research on the internet than 3D printer control boards is stepper drivers and/or stepper controllers. The external driver/controller recommended in the smoothieboard documentation is like $40 USD a piece so it seems ridiculous to spend $150+ on the board and then another $160 on external stepper drivers when the Azteeg seems to give me the same functionality for almost half the price. Does this make any sense at all? I also couldn’t possibly tell you the difference between all the different drivers/chips/controllers or why a cheap one is cheap and an expensive one is expensive. I will say, however, that the cost isn’t important as long as the hardware is reliable, quiet, and performs extremely well.
More so than the two boards above it seems like the Duet and Beaglebone boards aren’t as popular and the websites feel a little gimmicky to me personally. I want to get the best possible mainstream board not a niche board from a company that only guarantees it’ll work properly if you buy all the secondary hardware/accessories from them and they decided to reinvent the wheel on the firmware/software front.
Can someone set me straight on this stuff?