Topics created by binterryan76

@binterryan76 ok, thanks for explanation, I confused it with polar because I don't see your second rotary axis in the image. And I already commented on this construction in the other thread 😉 It's a long time ago, I forgot about it...

Comparing it with the printer dual-disc on hackaday, I would say they're different: the hackaday second rotary is mounted on the first rotary one.

Your one, if it's the violet stepper in the middle is fixed in XY position (only moving in Z) as well as the lower plate, so it's not Scara.

IMHO: if you place the nozzle to 0,0, in my understanding you can reach all positions (maybe 0,0 excluded), but the kinematics is not available (yet) in RRF, because it is of type three independent axes with respect to XY, but two of them rotary. The idea is interesting, because the steppers are on non-moving (only the middle slow Z-moving). In my opinion added gears may be necessary to get precision.

I hate it to say *), but robot kinematics will support this kinematics perfectly. But this kinematics is in the middle of a major redesign and not ready to use it.
https://docs.duet3d.com/User_manual/Machine_configuration/Configuring_RepRapFirmware_for_a_Robot_printer

*) because it sets me under time pressure. It will take a few weeks until I have a new RRF build. Most of those 2 to 7 axis constructions will be supported.

Yes that's possible. There is a wiki page about adding external drivers. You can connect the control terminals of an SSR between +3.3V and one of the extra heater signals on the expansion bus. The signal level is 3.3V, which is enough for most commercial SSRs but might not be enough for the cheap ones on AliExpress etc. unless you reduce the value of a resistor on the SSR.

You will need to connect a 4K7 resistor between the thermistor input and the VREF pin on the expansion bus.