New Z Stepper

[innkeeper]

So I have one of the old versions of the Z-stepper - one of the ~30 ohm models, that I felt needed to be upgraded.
I went on the search for a good replament, and also read the research ED had done on the stepper in his printer, but didn't care for the physical size he used as his solution.
so here is what I found. Busheng 17hd40005-300N and seems to be pretty widely available from many offshore suppliers its made by busheng motor in china.
its about 10mm taller then the current stepper. (measures out at 41.5mm) and uses the same jst connector so it should be plug and play
got mine shipped to me in 6 days from china.
(note: not plug and play, pins 3 and 4 are swapped)

will install it soon....

Specs:
2 phase
Screw : M8
Diameter: 8mm
Screw length : 300MM
Model: 17HD40005-300N
Step angle: 1.8°
Rated voltage: 2.4V
Rated current: 1.5A
Phase resistance: 1.5Ω
Rotor inertia: 57g.cm2
Holding torque: ≥420mN.m
Height of motor: 4.2cm
Winding inductance: 3.2mH

stepper.JPG

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[insta]

Watch out for the windings, just because the plug fits doesn't mean the wiring is the same.

[innkeeper]

thanks insta, i'll check that out now.

[innkeeper]

insta: sure enough... B and C wires are swapped, (pins 3 and 4) - good call! saved me time scratching my head for sure! Thanks

[innkeeper]

I did have to swap pins 3 and 4 on the connector, thanks insta, aside from that, the Z-stepper went in without a hitch, running at 1.35A and no were near as hot.
i feel a lot better about this stepper over the old one while running auto tramming because of all the constant micro-stepping.

[ednisley]

because of all the constant micro-stepping.

Turns out that stepper motors are constant-power devices: they dissipate essentially the same amount of power standing still as at full speed. The controller adjusts the winding current to put the rotor at the desired (micro)step and holds it there for as long as the motor stays in that position.

That said, the old Z-axis motor really wasn't intended for microstepping: good riddance!

Some controllers can (optionally) decrease the winding current after a preset time to reduce the idle power dissipation, which wreaks havoc with CNC machines that must maintain a fixed position against cutting forces.