Within the procurement community for encoder magnetic rings, sourcing personnel from around the world often spend a significant amount of time and effort working with suppliers. To purchase high-cost-performance magnetic rings, procurement personnel must ensure that the supplier has the matching magnetic ring molds and magnetizing coils (magnetizing fixtures) that meet their specific requirements. If the supplier does not have the necessary molds and magnetizing coils, the procurement cost will increase by $1,000 to $8,000, regardless of the order quantity, and these additional costs are unavoidable. Therefore, these procurement personnel need to inquire with each supplier individually, armed with describing their needs over and over again. Only by doing so can they maximize their cost savings.
The extra $1,000 to $8,000 we’re talking about covers the cost of making the mold for the magnetic ring and the special fixture used to magnetize it. The price can change based on the materials and how we make it. Here’s a quick video to show you how we magnetize these rings.
What are magnetic ring molds and magnetizing coils (magnetizing fixtures)?
Magnetic ring molds and magnetizing coils are essential equipment for the production of magnetic rings. A magnetic ring mold is a tool used to shape rare earth powder into magnetic rings. Different manufacturing processes for magnetic rings require different molds, and the cost of these molds varies accordingly. Magnetic rings produced using molds are initially non-magnetic. Typically, manufacturers magnetize these rings according to customer specifications. Magnetization involves applying a high voltage to the magnetic ring, and the magnetizing coil is responsible for this process. The magnetizing coil has a pre-set magnetization direction and polarity. The magnetization process is completed in an instant when the high voltage is applied to the magnetizing coil. Therefore, magnetic ring molds and magnetizing coils are essential costs in the manufacturing of magnetic rings.
How can I find a magnetic ring that meets my requirements without paying extra for molds and coils?
In the encoder magnet industry, there are numerous globally recognized brands, such as Renishaw from the UK, ic-haus and Bogen from Germany, Hutchinson from France, and CCmagnetics from China. One common trait among these brands is their willingness to share their Magnetic Encoder Ring Specification Data form, making it easier for customers to quickly find the encoder magnets they need.
However, unlike CCmagnetics, other international brands either have high minimum order quantities, high unit prices, or slow response times, and often ignore small and medium-sized R&D companies or teams.
For small and medium-sized magnetic encoder teams, spending an extra $1,000 to $8,000 to purchase a small quantity of magnetic rings is difficult to accept. If the purchase requirement is for a small quantity and does not require additional magnetic ring molds or magnetization coils (magnetization fixtures), CCmagnetics from China provides encoder magnets specifically for large, medium, and small companies, as well as research institutions. They have put forward the slogan: “Every (encoder magnets) size, under the sun.”
In CCmagnetics’ magnetic ring query tool, you only need to fill in 1-2 essential encoder magnet parameters to find the encoder ring specifications you want. After finding a specification that closely matches your needs, simply provide the SKU number to the sales representative, and they will provide you with a quote that does not require mold or magnetization coil fees.
If you find using the magnetic encoder ring query tool a bit cumbersome, you can also click this link to view them raw magnetic ring datasheet.
By publicly disclosing the specifications of magnetic ring molds and magnetization coils, ccmagnetics significantly reduce the time and effort required for encoder magnet procurement, and lower communication costs for both parties.
The following is an explanation of the parameters in this query tool/database:
- Dimensional Parameters:
- O.D (mm) represents the outer diameter, I.D (mm) represents the inner diameter, and Thickness represents the magnetic ring’s thickness or height. In the international encoder magnet ring industry, millimeters is the standard unit of measurement, with inches rarely used.
- Generally, if Thickness (mm) ≥ 15mm, it indicates that the magnetic ring is a special encoder magnet ring or is used in motors or other equipment.
- Magnetic Pole Notation:
- Master-track refers to the track with the larger number of magnetic poles in a radial or axial magnetic ring. Typically, in an axial magnetic ring, the Master-track is on the outermost side, while in a radial magnetic ring, it’s the track with the most magnetic poles. For the magnetic pole count of motor magnetic rings in the magnetic ring database, we also mark them on the Master-track.
- If the Nonius Track is not displayed, the magnetic ring must be a single-track magnetic ring, meaning it is not used for absolute magnetic encoders.
- Magnetic Material Classification:
- Magnetic encoder rings can be made of the following materials:
| Material Type | Typical Applications |
| Injection molded ferrite magnets | Commonly used in servo motor sensors, offering high precision and excellent shock resistance. |
| Bonded neodymium magnets | Often used in encoders with less than 50 poles or in motor magnets, providing a good balance of cost and performance. |
| Injection molded neodymium magnets | Widely used in servo motor sensors and motor magnets, offering better shock resistance compared to traditional sintered NdFeB magnets. |
| Ferrite magnets | Commonly found in Hall sensors. They offer the highest precision but have the weakest shock resistance, often requiring a metal carrier. |
| Neodymium magnets | If high surface magnetism is the primary goal, this is the preferred choice. |
| Copper metal ring/ injection molded neodymium magnets | Designed for improved concentricity and wear resistance. Often used in encoder magnets to ensure accurate positioning. |
| Copper metal ring/ injection molded ferrite magnets | Designed for improved concentricity and wear resistance. Often used in encoder magnets to ensure accurate positioning. |
| Sintered NdFeB magnets | Sintered NdFeB magnets are commonly used in motor magnets, offering very high surface magnetism. |
| Vulcanized rubber magnet material | This material is the most advanced for encoder magnets, offering high magnetic pole precision and excellent shock resistance, making it popular for robotic magnetic encoders. |
| NdFeB plastic coating | This coating improves the flexibility of NdFeB magnets. |
| Sintered neodymium magnets | If high surface magnetism is the primary goal, this is the preferred choice; however, it doesn’t perform as well as hot-pressed magnets. |
| Rubber magnets | These magnets are soft and have relatively low magnetic pole precision. |
4.Surface magnetic field
Surface magnetic field refers to the magnetic field on the surface of a magnetic ring. Typically, a hall sensor can detect a signal with a field strength of 100 gauss (or 10 millitesla) when placed 1 mm away from the magnetic ring. Of course, there are special applications that May require different parameters.
5.Magnetization method
6.Comments
The “Comments” section lists some typical applications for this encoder magnetic ring, but it’s not exhaustive. ccmagnetics is continually expanding its database. If this Q&A doesn’t fully address your needs, please don’t hesitate to contact ccmagnetics. Engineers are always ready to assist you.