2018年9月15日星期六

Common Discussions About Peculiarities of Step Motors

Help'. This is a common word during discussions involving peculiarities of step motors, which can have 4, 5, 6, and 8 wires. But today, I can say that this type of engine is no longer such a difficult challenge, as they are starting to get more and more standardized.

Step 1: Most Common Engines

Step 1: Most Common Engines

Here, we will talk about the most common china stepping motors: of 4, 5, 6, and 8 wires, which can be unipolar or bipolar. The best known of these is the bipolar, 4-wire, which is what we use, for example, with several drives, such as the TB6600, with the printer driver Router 4988, and with the DRV8825, among others. The 5-wire motors are unipolar. In 6-wire and 8-wire, these are rated as unipolar or bipolar depending on how the driver is connected.

Step 2: Coils


Most of the up-to-date stepper motors that I have are with eight windings. It is not because only two coils appear on the schematic that is just that.
So, as we're talking about this, I’m going to answer a question from a follower, Natan Bittencourt, and explain this better: "Fernando, I did not quite understand the issue of stepper motor resolution. Does it have to do with the amount of coils inside the engine?

 Can I vary the amount of steps within a complete rotation just by
varying the intensity of the electric current in the coils?”
The question essentially is this: if there were more coils in the engine, would it have more resolution? The answer is no. What causes resolution in the stepper motor is the number of phases with the number of teeth. It's almost always that. So when you search the web, you will find these diagrams with north pole with south pole.
This has the good and bad side. It serves synthetically, it has its utility, but it is bad to make a parallel with the stepper motor in the direction of the teeth, because when you play the sequence on the coil, you are millimetrically grinding your teeth. So beware of this kind of representation.

But another thing I want to address today is the waves.
In this image, we have the single step wave, the half step wave, and the micro step wave of 1/8. So the more you increase the micro pitch, 1/8, 1/16 (used frequently by 3D printers), 1/32, the drivers tend to throw a sine wave over the coils. However, I don’t see this in practice. This is because most of the drivers we buy are cheaper ones. Even the 17HS19-1684S-PG100, and 34HS38-4004D-SG13 are of the more simplified type and cheaper as a result. I have to say, however, that they are intelligent, do a lot of things, control micro-steps, but they don’t go as far as the last consequence of generating a sine wave at the output.

2018年9月11日星期二

Best Planetary Gear Unipolar Stepper Motor 9.6V 0.4A

9.6V, 0.4A, Planetary Gear Unipolar Stepper Motor 

9.6V, 0.4A, Planetary Gear Unipolar Stepper Motor


Unipolar Geared Stepper Motor
Rated Voltage: 9.6V
Current / Phase: 0.4A
Resistance / Phase: 24 Ohms
Inductance / Phase: 15 mH
Reduction Ratio:172:1
Max Rated Torque: 150 Kg.cm
Short Permissible Torque: 450 Kg.cm
Shaft: D-Shaped
Back Shaft for Encoder

The 9.6V, 0.4A, Planetary Gear Unipolar Stepper Motor is a unipolar stepper motor with 172:1 planetary gearing. The gearbox is rated for a maximum of 150 kg-cm despite the motor and gear ratio being able to provide 275.2 kg-cm.
Specifications

Planetary Gearbox:
Ring Material: Metal
Bearing at output: Ball bearings
Max. Radial load (10mm from flange): ≤80N
Max. Shaft axial load: ≤30N
Radial play of shaft (near to flange): ≤0.06 mm
Axial play of shaft: ≤0.3mm
Backlash at no-load: ≤1.5°

42STH Hybrid Stepping Motor
Rated Voltage (V): 9.6
Current /Phase (A): 0.4
Resistance /Phase: 24
Inductance /Phase(mH): 15
Holding Torque (kg.cm): 1.6
No of Leads: 6
Rotor Inertia (g-m2): 35
Weight (kg)0.22
Length L1(mm): 34
Max. Gear Ratio: ≤1:264

42JX150K Planetary Gearbox
Reduction ratio: 172
Number of gear trains: 4
Length(L2) mm: 52.6
Max. rated torque (kg.cm): 150
Short time permissible torque(kg.cm): 450
Efficiency: 66%
Weight: 620

Dimensions
 Size: 42H x 42W x 86.6L mm
 Weight: 840 g
 Shaft Diameter: 10 mm
Shaft Length: 19 mm

A Basic Guide on Encoder Devices Operating