Mercotac rotary connectors use a unique design principle, different from the brush sliding contact of a slip ring. The connection is made through a pool of liquid metal molecularly bonded to the contact, which provides a stable, low-resistance connection.

When there is rotation, the fluid maintains the electrical connection between the contacts without any wear. Below are some of the many reasons why Mercotac connectors are superior to slip rings.

First, unlike a slip ring, Mercotac connectors produce almost zero electrical noise due to their unique design. Second, the resistance across the rotary contact is less than one milliohm, which is much lower than the resistance of a slip ring.

Third, Mercotac connectors do not degrade the signal over time, which happens with slip rings. Fourth, slip rings require maintenance, and Mercotac connectors are maintenance-free. Fifth, Mercotac connectors are more compact and cost much less than slip rings of equal capacity.

Yes. The Mercotac connector is robustly constructed using a sealed ball bearing in a black anodized aluminum body. The electrical connections are made of brass or silver-plated copper for low resistance.

The white mounting bushing at both ends of the larger Mercotac connectors is made of insulating plastic potted with epoxy. Mercotac connectors are very durable and compact.

Yes. In addition to normal current and voltage uses, Mercotac connectors are ideal for low voltage/low amperage signal and current transmission. Unlike standard brush slip rings, Mercotac connectors use liquid metal as a conductor. This produces an extremely low noise signal transmission similar to the signal transmitted through a solid wire.

This makes Mercotac connectors superior to brush slip rings for signal and data transmission. The signal quality does not degrade, and no maintenance of the Mercotac connector is required.

The number of conductors, voltage, amperage, and RPM will determine which Mercotac connector model will be needed. First, decide on the number of conductors needed. Then, refer to the specifications page to determine whether a coaxial or modular unit will meet your amperage, voltage, and RPM requirements. Note: Although the larger Mercotac connectors are rated for 30 amperes, they work equally well for signal applications.

Mercotac rotary connectors are designed for mounting on the end of the rotating shaft in a vertical or horizontal attitude. The mounting method depends on the Mercotac model.

The larger Mercotac connectors are typically mounted in a hollow shaft or collar at the end of the rotating device by the plastic bushing or body. The Mercotac connector can be secured with a set screw or a split clamp system.

The smaller Mercotac connectors connect to the electrical receptacle and use this as both mounting and electrical connection. These receptacles are knurled and designed to be press-fit into a hole in the end of the rotating device.

The mounting eccentricity should be less than .005″ TIR (total indicated runout). The preferable method of mounting the Mercotac connector is with the black body rotating. Both ends of the Mercotac should not be rigidly mounted; one end needs to float freely.

If necessary, a floating torque arm can be used to prevent the stationary end from rotating. Note that Mercotac connectors are not designed to support any load.

No, Mercotac connectors have a top and a bottom. An arrow on the side of each unit specifies the top. A vertical mounting would position the Mercotac with the arrow pointing up.

Mercotac connectors can be mounted vertically or at any angle between vertical and 90 degrees horizontal. This allows for virtually any mounting attitude that would be needed. However, they cannot be mounted with the arrow pointing down horizontally or upside down.

All larger Mercotac connectors with lead connections are supplied with push-on disconnects. The smaller Mercotac Coaxial connectors use plugs available separately for each model to which the customer’s wires can be soldered.

When connecting wires to the stationary floating end of the Mercotac connector, allow sufficient length so as not to pull on the connector. Do not attempt to weld wires directly to Mercotac terminals. This will damage the internal parts, causing the connector to fail and void the warranty.

No. Attempting to weld wires directly to a Mercotac connector will overheat and damage the internal parts, causing connector failure, and void the warranty. Proper disconnects are available for Mercotac connectors and should always be used.

The eight-conductor Mercotac model is currently the largest connector available. There are two options if more than eight conductors are needed. First, if there is access to both ends of the rotating shaft, two Mercotac connectors can be used. This would increase the number of available conductors to a maximum of sixteen.

If this is not possible, a Mercotac connector can be combined with a standard slip ring that has a hole in the center. The Mercotac connector would be used for the sensitive signal connections and the slip ring for any power connections.

It depends on how wet or corrosive the environment is. Although Mercotac connectors are constructed with corrosion-resistant materials, they may not be suitable for all applications depending on the corrosives to which they are exposed.

They are also not suitable for use in “wet” environments without protection. Mercotac connectors are available with stainless steel ball bearings for use in wet or corrosive environments.

We also recommend using the “Boot Kit” accessory for additional protection with larger models. This increases the IP protection rating of the Mercotac to IP51.

All Mercotac connectors are guaranteed for a full year from delivery. Life expectancy depends on several application-specific factors such as vibration, temperature, RPM, mounting eccentricity, etc., and therefore cannot be accurately predicted for all applications.

However, without vibration and all other specifications within tolerances, Mercotac connectors typically provide years of trouble-free service. Under controlled test conditions, they typically last over a billion revolutions. Obviously, Mercotac connectors are completely maintenance-free.

Vibrations or sudden movements can significantly reduce the life of the Mercotac connector or even cause failures. Vibration moves the liquid metal conductor away from the contact area, which can cause open or shorted channels. If there is vibration in the application, a vibration-isolated mounting should be used to mount the Mercotac connector.

At the moment, we do not offer models with a through-hole in the center. Mercotac connectors are designed to be compact for mounting on the end of the rotating shaft, which makes them less expensive and more durable.

Indeed, either end can be connected to the rotating device. However, it is preferable to mount the Mercotac so that the body rotates. The body and the lower bushing are pressed together as a single unit. The upper bushing (identified by the “UP” arrow on the body) is mounted on a ball bearing and rotates independently of the body.

Please see the rotating model on the left which shows the body and lower bushing rotating with the upper bushing stationary. If a unit needs to be mounted vertically, below the rotating device, mounting the Mercotac by the upper bushing with the body floating stationary is acceptable.

No. Mercotac connectors contain elemental mercury, which is regulated by the European Union’s Restriction of Hazardous Substances (RoHS) directive. However, this directive does not prohibit the import and sale of industrial parts because it only covers consumer electrical and electronic products. Therefore, Mercotac connectors can still be legally purchased and sold in Europe and other parts of the world for non-consumer applications.