I dunno if comparing the unipolar with bipolar can actually give some conclusions, so i'd rather skip that fishy part.
> Are there common stepper motors out there that have a good torque range and micro-stepping but
> just aren't very well suited to RepRaps because of their electrical characteristics?
Yes, wront type are high inductance ones, and generally means thin wiring + extra turns, so also are a kind of a high coil resistance. For example if the coil resistance is 30 ohms. Or voltage written on the label is 12V, neither are good, in spite of the fact we will actually use it at 12v. Both need to be lower, ideally. From the link of mr Nophead here in the tables at the bottom you can see that second motor with 35ohms, 14v, and 44mH is of the wrong kind. As a side note anyway, motors dont have microstepping, but drivers do.
> Obviously my new motors are within the range of the Vref pot on the driver, but in a slightly higher voltage range.
"The ROSC terminal has three settings:
▪ROSC tied to VDD — off-time internally set to 30 μs, decay
mode is automatic Mixed decay except when in full step where
decay mode is set to Slow decay
▪ROSC tied directly to ground — off-time internally set to
30 μs, current decay is set to Mixed decay for both increasing
and decreasing currents for all step modes.
▪ROSC through a resistor to ground — off-time is determined
by the following formula, the decay mode is automatic Mixed
decay for all step modes. tOFF ≈ROSC⁄825, Where tOFFis in μs."
> Should I favor the old motors on the basis that they're (a) quieter, (b) require less current,
> and (c) have plenty of unipolar torque? On the other hand the new motors are a bit prettier than the old ones.
If i were you i would choose to stay with bipolar ones, yes, and specs like 2.6v ~1.6A ~1.6ohms looks ok.
> Are there common stepper motors out there that have a good torque range and micro-stepping but
> just aren't very well suited to RepRaps because of their electrical characteristics?
Yes, wront type are high inductance ones, and generally means thin wiring + extra turns, so also are a kind of a high coil resistance. For example if the coil resistance is 30 ohms. Or voltage written on the label is 12V, neither are good, in spite of the fact we will actually use it at 12v. Both need to be lower, ideally. From the link of mr Nophead here in the tables at the bottom you can see that second motor with 35ohms, 14v, and 44mH is of the wrong kind. As a side note anyway, motors dont have microstepping, but drivers do.
> Obviously my new motors are within the range of the Vref pot on the driver, but in a slightly higher voltage range.
"The ROSC terminal has three settings:
▪ROSC tied to VDD — off-time internally set to 30 μs, decay
mode is automatic Mixed decay except when in full step where
decay mode is set to Slow decay
▪ROSC tied directly to ground — off-time internally set to
30 μs, current decay is set to Mixed decay for both increasing
and decreasing currents for all step modes.
▪ROSC through a resistor to ground — off-time is determined
by the following formula, the decay mode is automatic Mixed
decay for all step modes. tOFF ≈ROSC⁄825, Where tOFFis in μs."
> Should I favor the old motors on the basis that they're (a) quieter, (b) require less current,
> and (c) have plenty of unipolar torque? On the other hand the new motors are a bit prettier than the old ones.
If i were you i would choose to stay with bipolar ones, yes, and specs like 2.6v ~1.6A ~1.6ohms looks ok.