2-wire stop switch vs. 3-pin connector on DuetWifi board

  • Hi all. I'm installing a DuetWifi as a replacement for a fried Melzi board on a Monoprice Maker Select v2 (Wanhao i3 Duplicator clone).

    The stop switches on the Wanhao use 2 wires, but the sockets on the DuetWifi board have three pins. I'm not sure what to do about it.

    My educated guess is that I would have to cut off the 2-wire connectors coming from the switches, and crimp on new pin thingies in a 3-pin connector using the outside two pins, and leave the center pin (3.3v) alone. Would that be correct?

    And what do you call the wire end thingies and the plastic male and female connectors that they mate with? I want to buy a set of crimpers to make this easier. Thus far I've had to swap a few connectors, and I've been crimping by folding the little tabs over with needlenose pliers, putting a tiny drop of flux onto the tabs/wire ends, and tinning that joint with a tiny amount of solder. I'd like this to go more smoothly and quickly, and less kludgey.

    So, can anyone explain the stop switch wiring to me?

  • For the endstops, use the outer two pins, the center 3.3vdc isn't used on two wire switches. See https://duet3d.com/wiki/Connecting_endstop_switches

    I use this crimper: https://www.amazon.com/gp/product/B00DHCRVSC

  • I usually use PA-09's

  • And the Connectors are Molex KK 2.54 pitch ones

  • administrators

    The HT225D crimper is inexpensive and widely available on eBay, Amazon etc.

  • Thanks guys! I'm going to run up to Fry's Electronics and see if they have a set of crimpers (too impatient to get this thing running to wait for Amazon at this point). If they don't have any I'll probably just make these ends using my kludgy needlenose pliers technique.

    What's funny is that the guy who convinced me to go with the DuetWifi said that all but two of his wires from his Wanhao i3 fit just fine on the DuetWifi board, and he only had to crimp two. In fact with my particular version of the Melzi board the connectors use are all different. I was able to get most of the 4-pin connectors to fit by just carving a little plastic off one side, but they aren't the correct connectors, and I'll get some more of the correct ones and convert them all over so they fit properly.

    I'll go ahead and cut off the 2-wire connectors from my end stop switches and put the 3-pin Molex connectors on, using just the outer two wires, and hopefully I'll have this thing up and running this evening.

  • I didn't think they used different connectors on a rebranded printer, sorry đŸ˜•

  • administrators

    Did you get a bag of connectors in with the DuetWifi? I know that does not help with the crimping, but there should be enough in it for all the connections

  • darookie, no worries at all, I completely acknowledge that 3D printing is still, in a lot of ways, in the "tinkerers" phase, where unless you are willing to spend thousands of dollars, some tinkering will be required. Having to change some connectors over isn't that big a deal, as long as I have the connectors and tools that make it easy. I just got home from Fry's with some crimpers, so this should go easier.

    T3P3Tony yes, the DuetWifi came with a bag of connectors, so I should have enough to get this done.

    I'll update again later tonight, hopefully with a report that it's all up and running and I've gotten my first prints with the i3 since the upgrade, and it was quiet and with high quality! fingers crossed…

  • Ok, I got everything connected up. It wasn't without its hiccups, but I worked through them. Somehow, magically, the wiring between my Z stop switch and the DuetWifi board went bad. I tested this with a multimeter and proved that it was the wires running from the printer in the main bundle of wiring. I spliced in a new length of wires between the Z stop switch and the board and now it works fine.

    I'm left with a single issue: I'm getting an error message from the bed heater. I've tried both orientations of the pins for the bed temp sensor, and the behavior is the same either way (I don't know enough about the temp sensor to know if there's a polarity or not.

    I'll post that in another thread so that it gets new eyes.

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