Duet 3 VH stepper connector wire size options

  • Slowly working through my build with a Duet 3, and while I do have one nema 23 motor, the rest are 17's and have the usual little JST-PH (I think) 6 pin plugs. What is the best option for wiring into the giant JST VH pins?
    Solder on some 20 gauge extensions?
    Attempt to crimp the usual 24-26 gauge stepper motor wiring and a tiiiny bit of solder?
    Buy male JST-PH male pins/connectors and force them to crimp onto 20 gauge (which is too large, as far as I can tell) to make my own complete wiring with RGB 4 wire cable?

  • I had no trouble crimping "regular motor wires" into the larger connectors. Just squeeze hard!

  • And if you find that the 'pull test' is not passed then double up the BARE wire at the larger connector of the Duet. Solder on the wiring is bad juju!

  • @jens55 said in Duet 3 VH stepper connector wire size options:

    Solder on the wiring is bad juju!

    ...to follow on from that if you do find yourself soldering in looms stress relief is essential. Agree though, a headache (/future gotcha) worth avoiding. As we are advised against unplugging steppers while the board is live for fear of killing a driver I'm guessing there is a chance a bust motor cable (eg failed solder joint) also risks cooking a driver.

  • Splicing two wires together, if done PROPERLY, is fine. The problem is that most people don't do it properly, so the only strength of the joint is the solder itself.

    That being said, it's completely unnecessary for the VH connectors. See the previous replies suggesting that the bare wire be doubled (or even tripled) for a good crimp.

  • Gave a really long strip and doubling over a shot and it seems good enough. I can still yank it out with a little force on test crimps only on the inner-crimp but at least I can be confident it's an acceptable electrical connection.


  • I did all my 13 steppers (so 52 wires) by stripping back twice as much insulation as needed then doubling it back on itself. Then I shortened the wings that wrap around the insulation by about 50% so they were only half as long. That technique worked fine for me.

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