Alternatives to Moog slip rings and rotary joints

In short:Capsule, through-bore, Ethernet, high-current, fibre optic and marine slip rings from other makers can replace many Moog parts, but equivalence depends on matching circuit count and ratings, data bandwidth, speed, bore, sealing, contact technology, life and any approvals, not just the outline drawing.

What Moog makes in rotary transmission

Moog Inc. is a US motion control company serving aerospace and defence, industrial and medical markets. Its slip ring and rotary products range is broad, running from miniature capsules to large-diameter rings for CT scanners. Moog is a trademark of its owner.

The commercial and industrial line includes compact slip rings, Ethernet slip rings, high-speed capsules (Moog quotes up to 10,000 rpm with fibre brush contacts), large-diameter slip rings and through-bore designs using Moog’s fibre brush technology. Alongside these sit fibre optic rotary joints, rotary unions, multiplexers and media converters, plus marine, wind, medical CT and defence products such as turret, helicopter and electro-optic slip rings. Typical uses include camera systems, robotics, packaging, medical equipment, radar and subsea vehicles.

Why engineers look for a Moog alternative

• Lead time. Slip rings are often built to order, and a long lead time on one part can delay a whole machine.
• Second source for production security, especially on a part with a custom circuit list.
• Budget, where a standard catalogue part can meet the specification.
• Legacy parts. Moog keeps a legacy products section for end-of-life parts not intended for new projects. If your part is there, our find a replacement service can check options.
• A different form, such as a flatter pancake design, a larger bore or integrated Ethernet.

What to check so a slip ring is genuinely equivalent

1. Circuit list. Number of rings, current and voltage per ring, and which rings can be paralleled.
2. Signals and data. Analogue, encoder, fieldbus, Ethernet speed, video or RF, with noise or bit error targets.
3. Speed. Maximum and continuous rpm, and whether rotation is continuous or oscillating.
4. Mechanics. Bore or shaft size, outer diameter, length, flange, anti-rotation tab and lead exits or connectors.
5. Contacts. Fibre brush, gold-on-gold or carbon brush, which affects torque, noise, life and maintenance.
6. Environment. IP rating, temperature, humidity, shock and vibration, and pressure for subsea.
7. Life. Rated revolutions, and any maintenance interval.
8. Approvals. Medical, marine, hazardous area or defence qualification where they apply.

See our guides on how to select a slip ring, how to specify a slip ring and Ethernet through slip rings.

Slip ring alternatives in our supply network

• AR/BR/CR capsule slip rings: gold-to-gold contacts, up to 76 circuits in a small body. See capsule slip rings.
• ER Series through-bore slip ring: standard bores from 12.7 to 100 mm for power, signal and fieldbus. See through-bore slip rings.
• Ethernet slip ring: 100M or Gigabit channels with power and signal, in shaft or through-bore form.
• FR Series fibre optic rotary joint and the fibre optic integrated electrical slip ring for optical data.
• BHR carbon-brush slip ring: up to 500 A per circuit for heavy plant. See high-current slip rings.
• High speed slip ring: built for 800 to 15,000 rpm on test rigs.
• Waterproof slip ring (IP64 to IP68) and large size slip ring with through holes quoted to 1,000 mm.

How the comparison is made

The table under this text lists each Moog series we hold data for with the closest product from our supply network, compared on published figures only. “Equivalent” means a product that meets the stated specification for your application, confirmed by an engineer, not an identical part. Specify Motion is not affiliated with, authorised by or endorsed by Moog Inc., and no logos are used. Names are used only to identify products.

Many slip rings are custom. If yours is, send the drawing and circuit list and we will tell you whether a standard part meets it or a build-to-print is the better route.