Extruder wiring

I'm getting confused... several questions:

1) I don't see any build instructions on the "valve solenoid", but do see it on the single arduino wiring diagram [reprap.org]
Is this necessary (other than it keeps things neater)?


2) Referring to the last picture with the 4-wire ribbon [www.reprap.org] , do the nichrome wires go to the PWM driver board? And the thermister wires go to the Temperature sensor board? Then why are the 4-pin all connected together in the picture?

Is there any documentation on how to wire all the leads to/from the extruder?

Thanks for your help.

-Arthur

> 1) I don't see any build instructions on the "valve solenoid",
> but do see it on the single arduino wiring diagram

Earlier diagrams did not have the valve wiring. I think this experimental feature was added to the diagram but not the build instructions. I would ignore the "valve solenoid" wiring for now.

> 2) Why are the 4-pin all connected together in the picture?

The pin header at the end of the short piece of ribbon cable gives a way of disconnecting the extruder so it an be worked on. Any small four-pin connector should work.

Thanks John -- that's helpful.

This sounds obvious, but the nichrome wire goes to the PWM board? And the thermistor goes to the Temp sensor board still? Orientation doesn't matter.

2 of the 4-pins on the pin header are for the nichrome, and 2 will be for the thermistor in a config similar to this right? [www.allelectronics.com]

Yes. Two wires for he nichrome and two for the thermistor (or thermocouple). There's also two wires for a fan and two for the extruder motor. In future there may be several for the extruder motor shaft encoder and two for the anti-drip valve solenoid. Perhaps another two for a switch to sense when the plastic has run out.