Gen 3 wiring questions

I am looking at my gen 3 pcbs before I make them and I am trying to decide what connectors and cables I need to wire it up. I have motherboard v1.2, stepper driver v2.3r, extruder v2.2.

1)The stepper drivers have two 8p8c sockets for the endstops but I can use 3-pos 2.54 wire to board conenctors if I like can't I?

2)It seems you need to use 8p8c connector plus cables for the extruder though, is that right?

3)What is the 10pos quadrature on the extruder for? Do I connect anything to it?

4)I am guessing that I only have one wire from the motherboard to the extruder which will be RJ45 patch cord yes?

5)From the motherboard, to each stepper driver, I need one 10pos ribbon cable each yes?

6)I can't make these boards yet becuase I need to wait on a couple of parts to arrive, but can anyone tell me what lengths of cables I need so I can make these before I build my MENDEL? I need to know length for 3xendstops and 3xribbon cables and 1xRJ45 patch cable. Thats everything right? I will use an ATX for power.

7)Does anyone know what sort of thermistor I should purchase?

Please, if anyone knows the answer to any, let me know. I numbered them to make it easy to reply if you only know the answer to one question. Thanks a million

Gen 3 is obsolete and too old. The current firmwares use only one mcu. The extruder board 2.2 was more of a dc motor controller for dc motor extruder, but now we use steppers for extruder.

You could use only the motherboard 1.2 and have some temp sensor made and wired to one adc pin on mb1.2, but that would be tedious to make. Its way simpler to use an atmega board instead and if you want to make smth could make some stepper drivers, probably like those version 3.3. Or use ramps shield for atmega with pololu drivers.

You may want to look into gen3+ if you persist in building a Gen3. That replaces the extruder board and lets you run modern firmware. You would still be better off with RAMPS, Gen6 or Sanguinolu, but if you've invested money in gen3 it can be made to work. As for your questions:

1) Yes, any connector that fits the footprint will do. I soldered my cable at the endstop end though, one less connector to go wrong.

2) Again, you can use any connectors that fit the footprint on the board. The RJ45 footprints don't make it easy to find a substitute but you could use a pair of 2.54mm pin strips in a pinch. If you go for a Gen3+ you won't need an extruder board at all.

3) For connecting quadrature sensors, which some people experimented with back in the days when extruders had DC motors. Useless with a stepper - if its not skipping steps then you already know where it is, if it is skipping steps then you lose quality while you compensate, and you'd need a custom firmware to even try.

4) If you were running a DC motor extruder like the extruder controller was designed for, you could use one Rj45 cable. With a stepper extruder, you need some additonal wires to carry step and dir signals. Google will turn up details, Again, you can junk the extruder board in exchange for Gen3+.

5) Correct

6) Im sure google will turn up those lengths, but its best to cut to length as you wire up the machine.

7) 100K thermistors work well. 10k or lower don't give enough resolution at hot end temperatures. Your firmware should mention some part numbers along with its thermistor tables on in its configuration files.