The stepper motor is the “heart” of the carving machine. If selected correctly, the carving machine can work quickly and steadily; Choosing the wrong one, either throw away useless steps or suffer from resonance noise. So, how to choose the stepper motor for the engraving machine? This article will provide you with a complete practical guide from core parameters, common misconceptions, to selection steps.
| Motor Type | Step angle | Features | Applicable Scenarios |
| 2phase | 1.8° | Low cost, large low-speed vibration, and fast torque attenuation at high speeds | In situations where high speed and low precision are not required |
| 3phase | 1.2° | Less vibration, high-speed performance 30%~50% higher than two-phase | In situations where high speed, precision, and stability are required |
A fatal weakness of stepper motors is that the torque rapidly decays with increasing speed. It is generally recommended to control the actual working speed below 600rpm; When the torque exceeds 600rpm, there is a significant decrease. When it exceeds 1500rpm, closed-loop stepper or servo motors should be considered.
Many people are struggling with which control method to choose. Based on the actual working conditions of the engraving machine, clear suggestions are given here
| Motor Type | Преимущества | shortcoming | Applicability of carving machine |
| Open-loop stepping | Cheap and easy to control | Losing steps without realizing it can easily accumulate errors | Entry level, light load, not concerned about occasional waste |
| Closed loop stepper (with encoder) | Low speed torque is large, step loss can be corrected | High speed is still inferior to servo | The first choice for carving machines – balancing cost and reliability |
| AC servo | High speed, high precision, fast response | Expensive and complex debugging | Professional industrial carving machine, mass production |
For most small and medium-sized engraving machine users, closed-loop stepper motors are currently the most cost-effective choice – they retain the advantages of low-speed and high torque stepper motors, while solving the pain point of step loss through encoder feedback
Step 1: Calculate the load torque
Calculate the required thrust based on the transmission method of the engraving machine (usually ball screw), and then convert it into motor torque. Formula reference:
Thrust=(2 x π x motor torque x transmission efficiency)/lead screw
Step 2: Compare the speed torque curve
It is necessary to check the “torque frequency curve chart” provided by the manufacturer to confirm that the motor can still output sufficient torque at the set operating speed. Relying solely on static torque selection is the most common mistake made by beginners.。
Step 3: Select the machine base number
Corresponding relationship between common carving machine stepper motor base numbers:
42 stepper motor (NEMA17): small desktop engraving machine, light load
57 stepper motor (NEMA23): the most mainstream choice, suitable for most small and medium-sized engraving machines
86 stepper motor (NEMA34): large engraving machine, heavy-duty
In terms of driving voltage: 57 motors are recommended to have DC 24V~36V, 86 motors are recommended to have DC 46V or above, and 110 motors are recommended to have DC 80V or above to achieve good high-speed performance
Step 4: Determine the driver and subdivision number
Avoid using full step mode (with high vibration), and set up subdivision drive
When operating at low speeds, choose a larger fraction to ensure smooth operation, reduce vibration and noise
The current of the driver used should be greater than the working current of the motor
Misconception 1: The greater the torque, the better
Blindly pursuing high torque not only increases costs, but may also lead to overload vibration or efficiency decline. What is suitable is the best.
Misconception 2: Neglecting heat dissipation issues
The continuous operation of stepper motors generates a large amount of heat, and the appropriate driving current should be selected according to the load and operating conditions, while considering the heat dissipation design
Misconception 3: Open loop stepping “fits together”
If the equipment has certain value, it is recommended to spend a little more cost on closed-loop stepping – the cost of tool damage or workpiece scrap caused by one step loss may far exceed the price difference of the motor。
Ordinary DIY carving machine: 57 two-phase open-loop stepper+fine fraction 8-16 subdivision driver → lowest cost
Stable desktop engraving machine required: 57 closed-loop stepper+adaptive closed-loop driver → Highly recommended
Heavy duty or industrial engraving machine: 86 or 110 three-phase stepper/servo+high-voltage driver → configured as needed
When selecting, remember to first calculate the load demand, then look at the torque frequency curve, and finally determine the machine seat number – after completing these three steps, you will have chosen the right stepper motor for your engraving machine.。
