High-speed slip ringsLegacy
Moog PH Series high-speed slip ring
Through-bore high-speed slip ring rated to 20,000 rpm with 8 or 12 circuits; now an end-of-life legacy product.
Need this part, a replacement or a complete package? Our experienced UK engineering team helps you select, source and obtain the right products, with pricing, delivery coordination and after-sales support.
Moog lists this series as legacy. We can help with spares for installed machines, a migration to the replacement, or an alternative. Find a replacement.
Pricing and availability
Get pricing, sourcing and replacement support
Need Moog parts, a replacement or a suitable alternative? Send us a part number, or tell us what the machine needs to do. Our UK engineers will come back with the right product, pricing, lead time and delivery, whether that is the original part, a checked alternative or a complete axis.
- Original parts or a checked alternative
- Pricing, lead time and delivery in one reply
- Components, complete axes and ongoing support
No obligation. Add what you know and an engineer will help with the rest. Prefer to configure it? Build a specification.
Spec builder
Specify what you need instead of PH Series
Select every part you need and answer the questions an applications engineer would ask. Our engineers use your specification to come back with the right products, pricing and lead times. You see your summary before we ask for any details.
Already know the part number? Send it to us directly.
- 1Products
- 2Performance
- 3Environment
- 4Volumes
- 5Your spec
What are you specifying?
Select everything you need. A motor, drive and gearbox can be specified together as one axis.
Key specifications
| Circuits (max) | 12 |
|---|---|
| Current per circuit (max) | 2 A |
| Voltage (max) | 50 V |
| Speed (max) | 20,000 rpm |
| Bore | 38.6–38.6 mm |
Summarised in our own words from Moog Inc.'s published data; series maxima, individual models vary. Last checked 2026-10-29. Source 1 · Source 2 · Source 3
Notes on this data
Dimensions converted from published inches. Catalogue part numbers 80042-950 / 80043-950.
Specify Motion is not affiliated with Moog Inc.. Moog and PH Series are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Engineer support
Speak to our engineers about your project
Our experienced engineers are on hand, ready to help with your project. Whether you need the Moog PH Series itself, help sourcing it, or a modified or custom design built around your load, speed and space, tell us what the machine has to do and we'll come back with the right option.
- Help sourcing PH Series and spares for installed machines
- Modified and custom designs when a catalogue part doesn't fit
- Complete axis: motor, drive, gearing and feedback matched together
Typical applications
What a high-speed slip ring is
A high-speed slip ring is a rotary joint built to run at speeds well above general industrial units, typically from a few thousand to over ten thousand rpm. To manage heat and wear, designers keep ring diameters small, use precisely balanced rotors and high-precision bearings, and select brush materials and contact forces for the higher surface speed. Some designs use liquid or forced-air cooling. Most high-speed units carry low-level signals such as strain gauges and thermocouples, with limited power circuits.
When engineers choose a high-speed slip ring
Choose a high-speed design for test rigs, spindles, centrifuges, turbines and tyre or wheel testing where the rotating sensors spin far faster than a normal slip ring allows. The trade-offs are circuit count, current and life: speed limits how big the rings can be, and brush wear rises with surface speed, so service intervals may be shorter. For very high data rates at speed, telemetry or contactless transfer may be an alternative. Balance and runout of the mounting shaft are critical.
How to specify the Moog PH Series
Send these with your enquiry and an engineer can confirm the right PH Series variant or an equivalent:
- Maximum and continuous speed (rpm)
- Duty: continuous running or short test runs
- Number and type of signal circuits, such as strain gauge, thermocouple or encoder
- Acceptable electrical noise (mΩ or µV)
- Power circuits and current (A)
- Shaft or bore interface and permissible runout (mm)
- Cooling, lubrication and expected service interval (h)
Common mistakes to avoid
- Mounting on a shaft with runout that the slip ring bearings cannot tolerate at speed
- Quoting peak test speed but not how long the rig runs there
- Using standard thermocouple wire through the rings and creating junction errors
- Forgetting the slip ring's own drag torque and inertia in rig calculations
Moog PH Series: frequently asked questions
Can you help replace Moog PH Series or source the original?
Send the full model code, quantity and required date. Our engineers can check original-part availability and assess suitable alternatives, including supply-network options where appropriate. We confirm compatibility and any changes needed before recommending a replacement.
What is the Moog PH Series?
Through-bore high-speed slip ring rated to 20,000 rpm with 8 or 12 circuits; now an end-of-life legacy product. Published series figures include circuits 12, current per circuit 2 A, voltage 50 V, speed 20,000 rpm. It is made by Moog Inc.; Specify Motion can help source it or propose an equivalent.
Who makes the Moog PH Series?
The Moog PH Series is made by Moog (Moog Inc.) and is listed here for engineers comparing options. Specify Motion is not affiliated with Moog Inc.; brand names are used only to identify the product.
What is the circuits of the Moog PH Series?
The published series maximum circuits is 12. Individual models and sizes in the PH Series range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is the Moog PH Series still available?
Moog lists the PH Series as legacy. We can help with spares for installed machines, a migration, or an equivalent from our supply network that meets the same published figures.
How fast can a slip ring rotate?
General industrial slip rings are typically rated to a few hundred rpm, while dedicated high-speed designs commonly reach several thousand to over ten thousand rpm. The practical limit depends on ring diameter, because surface speed sets brush wear and heat. Small-diameter capsules reach the highest speeds, while large-bore units are rated lower. Always check both maximum speed and continuous rating.
Can strain gauge signals pass through a slip ring cleanly?
Yes, when the rings use low-noise precious-metal contacts and the circuits are allocated well. Use dedicated rings for each bridge connection, keep them away from power, and consider amplifying or digitising on the rotor where noise is critical. Contact resistance variation is the main noise source, so state the acceptable level and the expected speed.
Further reading: How to select a slip ring · How to specify a slip ring · Slip rings
Other high-speed slip rings series
Engineer support
Our engineers are ready to help with your project
Tell us about your project and how you use the Moog PH Series: the load, speed, duty and environment. An experienced engineer will review it and reply, normally within one working day.
- Reviewed by an engineer, not an autoresponder
- Like-for-like and better-fit alternatives
- Standard, modified and custom options
Prefer to configure it? Use the spec builder.
How it works
From enquiry to delivery
Send a part number or describe the application. Our engineers take it from there: the right product, a clear quotation, and delivery and support arranged.
- 01Tell us what you needSend a part number, or configure the application, quantities and timing.
- 02An engineer reviews itWe check the specification and find the original part, a checked equivalent or a complete axis.
- 03Receive your quotationProducts, pricing, lead time and compatibility notes in one reply.
- 04Order and deliveryWhen you are happy, the order is placed and delivery and after-sales support are arranged.