With knowing zero about if such suggestions are reasonable or possible with the number of IO pins and such...
Perhaps go both ways. Two are series wired and two that are parallel wired (or share a common header between the two different ways)
Reduce different part count and increase flexibility. Make all 3 20A. Just because they are all 20A rated doesn't mean they have to be ran at that current or be capable of providing 60A total.
I'd like to see more low-current options. Even with my printer now I have a hot end cooling fan, bed fan, and LED lighting. Other people have a larger whole bed fan to help with cooling a part after the job is finished. With multiple hot ends you might have a need for independently controlling more fans.
Probably enough. But I can't help but think someone, somewhere is going to think of a need for just one more endstop|thermistor|probe...but you'll probably have that no matter how many you have. Not sure if the 4-pin connector is just for the z-probe switch or also a servo, but if not at least 1 servo port would be nice. You have that mentioned further done with the expansion connector, but it'd be nice if all the necessary pins were together for power and control of the servo.
A couple of other things that I've thought about or I've seen asked is:
* ATX power supply connector in addition to dedicated screw terminals. Makes hookup super easy. Maybe just an optional connector or empty headers if cost is a concern?
* Headers for any indicator LEDs for remote locating somewhere else on the device. Could just be a header pin hole and the end user adds the header or wire if needed.
* Screw terminals in addition to headers for any connection including steppers and fans. Or option for screw terminals again to keep cost down
* A few headers for Vin, 12v, and 5v for powering "other things" that comes up down the road.
* PS_ON pin for turning on/off power supply...would also require being able to minimally power the microcontroller via 5VSB
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dc42
* Two Z motor connectors to make it easy to connect two motors in series.
Perhaps go both ways. Two are series wired and two that are parallel wired (or share a common header between the two different ways)
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* One heated bed output, rated at 20A.
* Two hot end heater outputs rated at 10A.
Reduce different part count and increase flexibility. Make all 3 20A. Just because they are all 20A rated doesn't mean they have to be ran at that current or be capable of providing 60A total.
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Two outputs for 12V fans etc., one with PWM, the other without.
I'd like to see more low-current options. Even with my printer now I have a hot end cooling fan, bed fan, and LED lighting. Other people have a larger whole bed fan to help with cooling a part after the job is finished. With multiple hot ends you might have a need for independently controlling more fans.
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* Three endstop inputs
* Three thermistor inputs
* A 4-pin connector for supporting several different kinds of Z probe.
Probably enough. But I can't help but think someone, somewhere is going to think of a need for just one more endstop|thermistor|probe...but you'll probably have that no matter how many you have. Not sure if the 4-pin connector is just for the z-probe switch or also a servo, but if not at least 1 servo port would be nice. You have that mentioned further done with the expansion connector, but it'd be nice if all the necessary pins were together for power and control of the servo.
A couple of other things that I've thought about or I've seen asked is:
* ATX power supply connector in addition to dedicated screw terminals. Makes hookup super easy. Maybe just an optional connector or empty headers if cost is a concern?
* Headers for any indicator LEDs for remote locating somewhere else on the device. Could just be a header pin hole and the end user adds the header or wire if needed.
* Screw terminals in addition to headers for any connection including steppers and fans. Or option for screw terminals again to keep cost down
* A few headers for Vin, 12v, and 5v for powering "other things" that comes up down the road.
* PS_ON pin for turning on/off power supply...would also require being able to minimally power the microcontroller via 5VSB