NEMA17 and NEMA23 Motors in Stock

I’ve just added three NEMA17 motors to the store: one 0.9° per step, and two 1.8° per step (the most powerful I could find, and a lighter one).  I also added a 0.9° NEMA23 motor (small for a NEMA23, but twice as powerful as the NEMA17), but that’s not in stock yet.

I also added a very nice 24 V 5 A power supply.  It’s a laptop-type power supply: a completely enclosed brick, with no vents or fans — a plus if you’re producing dust and chips.

5 thoughts on “NEMA17 and NEMA23 Motors in Stock

  1. Quick note after some research: watch out with 24v to pololu drivers, it can blow them up! You ideally want 18 volts supplied to the stepper shield, with the pololu pots turned down as far as possible, then slowly increased until the steppers make a smooth humm and there’s no skipping when load is applied.
    Also, 12V PC PSU’s work very well too, but you’ll likely have to turn the drivers to maximum power.
    Catalin, is there an indication when the shield kits are back in stock?

    • In my experience, it’s hard to fry a Pololu driver, if you have 47μF capacitors on VMOT and if you don’t connect or disconnect the motor while power is on (the latter is almost guaranteed to fry them, especially at 24 V). If your connections are secure, there’s nothing to worry about. Having played with 12 V, 18 V and 24 V, I can say that 12 V is too little and I could never get the acceleration and speed I wanted. 18 V is acceptable, but 24 V is better. I haven’t carried out a formal experiment, but it seems that the drivers don’t heat up more with the higher supply voltage. The motors are certainly quieter and can accelerate more. In any actual use scenario, you need active cooling, regardless of the supply voltage. A fan blowing from the side, so that there’s airflow both over and especially under the drivers, is ideal. Heatsinks help too, but not as much as you’d expect: the chips are designed to conduct heat through their bottom into the PCB.

      In any case, the motor current does not depend on the motor supply voltage, so don’t turn the pots up just because your supply is 12 V. What the higher supply voltage buys you is the ability to reach the desired current quicker with each step, meaning less loss of torque as the speed increases.

      As for the shields: I kinda dropped the ball on that one and forgot to order some of the parts. They should be back on Monday.

      • Thanks for the insight, i base my experience from 3d printer controllers which are a bit different i suppose.
        I read the fan tip on the shapeoko website, conveniently also posted by you 🙂

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