With an outer diameter of 105 mm, and a 21 mm axial height, the LSI 105-21 provides 1.2 N-m of continuous torque output, yet only weighs 414 grams

The latest LS Series motor set uses a fiber-wound technique to bolster magnet retention of the rotor assembly 

Camarillo, CA (May 31, 2024) – ThinGap continues to build out its LS Series of slotless motor kits with the latest release, the LSI 105-21. The new part has an outer diameter (OD) of 105 mm, and an axial height of 21 mm. With a maximum operating speed of 3,000 RPM, the LSI 105-21 has a 1-second peak torque output of 13.5 N-m, and a continuous one of 1.2 N-m.

Designed from the ground up, the LSI 105-21 was developed for use in space-based gimbals, such as Coarse Pointing Assemblies (CPAs) that perform critical laser-based satellite communications. All types of multi-axial gimbal systems can leverage the benefits of high-performance cogless motors, such as ThinGap’s LS Series, to directly drive movement and maintain position, while offering a large aperture and significant Size, Weight, and Power (SWaP) savings.

The LSI 105-21 marks the first time that an LS Series motor kit comes standard with a fiber-wound rotor. For high-speed and fail-safe applications, ThinGap deploys a thin, but strong filament of epoxy-coated fiberglass over the magnets in building the rotor assembly. This enhanced rotor provides an additional safety margin called out by some customers.

ThinGap’s LS Series of slotless motor kits range in size from 25 to 267 mm diameter, and torque from 0.1 to 12 N-m continuous and voltages from 24-400 volts. Most LS motors are available with an optional space-rating that includes the use of low outgassing materials, leaded-circuit boards and a Materials and Processes (M&P) list that conforms to NASA’s standards.

While the majority of ThinGap’s motors are bound for space or airborne gimbal applications, we have been proud to support Motocrane with their new advanced cinema gimbal system, Titan. Motocrane has integrated ThinGap’s LS Series of zero-cogging slotless motor kits into Titan, enabling smooth, high precision motion with even the heaviest camera systems. To learn more about Titan, see Motocrane’s video below.

While a majority of ThinGap’s motor kits are destined for airborne or spaceborne applications, the same attributes that help serve aerospace customers also are desirable for many medical applications. Smooth, zero-cogging, high precision motor kits, such as ThinGap’s are ideal for not only surgical robotics, but diagnostic and imaging equipment as well.

Modern surgical robotics systems require precise, exacting movement with no chance for mechanical disturbances to ensure the highest level of patient care. Zero-cogging motor kits are the ideal solution for true and accurate operator haptic feedback, as well as precision actuation. ThinGap’s TG Series motor kits have been used for haptic feedback for a surgical robotic system, due to the lack of both hysteretic drag afforded by the ironless motor architecture, enabling true force feedback without any disruptions.

ThinGap’s LS Series has seen integration in high-precision robotics due to the motor architecture’s extremely smooth, highly precise motion. Additionally, low profile motion solutions with a large internal aperture are desired for the ability to route optics or cabling through the center as part of deep system integration.

ThinGap’s motor kits have near zero Eddy-current, low or zero hysteretic drag, and a harmonic distortion of less than 1%, so torque output is directly proportional to current throughout the operating range, as well as providing smooth, zero-cogging motion. Additionally, ThinGap has maintained a long-standing relationship with a leading surgical robotics manufacturer supplying motors, and regularly works with other medical industry OEMs to produce tailor-made solutions that meet regulatory approval.

In recognition of Earth Day, ThinGap is excited to share NASA’s public release of data from the recent PACE Mission.

Image Credit: NASA

Launched in February, PACE is a mission to study the Earth’s oceans and atmosphere, and marks the first time ThinGap motors have received NASA flight certification. ThinGap supplied its LS Series motors that drive the satellite’s main instrument, the Ocean Color Instrument (OCI).

Read the full blog here

As a recent example of its custom motor capabilities, ThinGap recently shipped an assembly in support of a defense project that utilizes structural carbon fiber composite components to increase performance. While the company is no stranger to working with composites, with many current off-the-shelf products utilizing them, this project marks the first time these components have been sourced from a commercial vendor.

What is commonly referred to as “carbon fiber” in reality Carbon Fiber Reinforced Polymer (CFRP), a composite material typically composed of an epoxy-impregnated sheet of woven carbon-filament cloth that is layered, formed into a mold, and then cured in a kiln under vacuum conditions. The components made of the material that results from this process are extremely lightweight, and incredibly stiff with an excellent strength-to-weight ratio.

The individual fibers in modern carbon fiber are mostly composed of petroleum byproducts, with the development of pure, crystalline carbon fibers being how the material matured and was later industrialized. First synthesized throughout the late 19^th and early 20^th centuries, including by Thomas Edison for use as light filaments, these early attempts were unsuccessful as they were of low purity. It wasn’t until the early 1960s when Japanese and American chemists were able to produce fibers of the appropriate purity to be used as reinforcement in composites.

After substantial investment by the Royal Aircraft Establishment, a part of the British Ministry of Defense, the first industrially-produced carbon composite components came with the integration of a carbon composite compressor fan assembly in the Rolls-Royce Conway and RB-211 jet engines in the late 1960s. Through the 1970s, the material further matured with improvements in the quality of the filaments and adhesives, and by the early 1980s motorsports became another testbed for carbon composite materials.

The Rolls Royce Conway jet engine was designed for the Vickers VC-10 Airliner

Introduced for the 1981 Formula 1 championship, the McLaren MP4/1 was an early racing car with a fully carbon composite chassis. Similar to the high-performance nature of aerospace, motorsports benefitted from composites by enabling weight reduction without sacrificing strength and rigidity, ensuring McLaren a competitive edge, and before long carbon composites were prevalent in all forms of racing.

By the 1990s, production of even larger carbon composite pieces became possible, helping to reduce weight in the new Boeing airliner, the 777. The 777 was critical in introducing large composite pieces to aerospace, with the plane being 9% carbon composites by weight, being used in the rear fuselage, engine cowlings, control surfaces, and floor beams. In addition to saving weight, these new composite components were corrosion and fatigue resistant, which helped save on maintenance over the old industry-standard aluminum.

In 2007, Boeing introduced the revolutionary 787 Dreamliner which saw a massive increase the use of composites, now up to 50% by weight. Due to Boeing’s ability to produce large carbon composite pieces, the fuselage of the 787 is composed of three large single-laid sections that are then mated during assembly. Additionally, the wings of the 787 are primarily composed of carbon composites, with the materials ductility lending to the plane’s iconic wing flex.

With these desirable characteristics in mind, it was only a matter of time before an application came up that required carbon composites. To minimize unit weight and maximize rotor inertia in the new TGD 129-114 generator unit, ThinGap’s new assembly uses carbon composite for both the inner and outer sleeves that retrain the rotor’s magnets and are joined together by a purposely designed metallic top cap with fan blades that forces airflow across the stator. To learn more about ThinGap’s custom and modified capabilities, click here.

Showcasing ThinGap’s highly adaptable technology, the TGD 129-114 introduces carbon fiber components for the most extreme TG Series part set ever made.

Designed for the high-power and high-speed required in UAV and other Airborne applications.

ThinGap has completed its latest high-power motor-generator prototype, the TGD 129-114, in support of a Government-funded defense program. In generator mode, the new assembly is designed for a steady 10 kW of power output at 7,000 RPM and is capable of 45 kW at 20,000 RPM. Mechanically, the TGD 129-114 has an outer diameter (OD) of 134 mm (5.28 in.), and an axial height of 124 mm (4.91 in.), making it about the same size as a coffee can.

Developed for use by the United States Army in airborne applications, namely Class II unmanned aerial vehicles (UAVs), the TGD 129-114 is the most radical evolution of the ThinGap TG Series to date. Designed for the extremely high continuous speed requirements typical in airborne generator applications, as well as being strength and weight optimized. Previous TG Series part sets have been used as starter-generators in other UAV platforms.

To minimize unit weight and maximize rotor inertia, the new assembly uses carbon fiber reinforced polymer (CFRP) for both the inner and outer sleeves that retrain the rotor’s magnets and are joined together by a purposely designed metallic top cap with fan blades that forces airflow across the stator. First developed in the late 1950s, CFRPs have become ubiquitous in demanding, high-performance applications such as aerospace and motorsports to reduce weight while not sacrificing strength.

The TGD 129-114 demonstrates ThinGap’s ability to deliver tailor-made high-power solutions. With more than two decades of experience in the design and production of slotless motor kits, ThinGap leverages its proven designs and analytical modeling that results in highly accurate transitions from predicted performance to real world operation. Furthermore, the process steps needed to produce motors of all sizes are highly scalable, and ThinGap has shipped large class motors with up to 400 kW of output power.

Designed for Reaction Wheel Assemblies (RWA) and Flywheel Applications

Optimized for maximum inertia, giving the greatest momentum for the least amount of mass

Specifically built for use in vacuum, making it space compatible by design 

ThinGap has delivered to a commercial customer its latest purpose-built reaction wheel motor kit, the TGR 60-30. This newest motor kit has an outer diameter (OD) of 60 mm and an axial height of just 29.6 mm, providing a continuous in-vacuum torque output of 0.08 N-m, and a peak torque of 1.61 N-m. A complete datasheet is available on ThinGap’s website.

With a total part mass of 273 grams, the TGR 60-30 fits between the already released TGR 89-26 and TGR 29-12, showcasing the Company’s highly scalable stator architecture. In addition, the rotor of the TGR 60-30 is optimized for maximum inertia, giving the motor the greatest momentum for the least mass. As part of the industry’s first clean-sheet reaction wheel assembly product line, the TGR Series is designed for Attitude Control in SmallSat applications and other high precision systems.

Prior TG Series models have been widely used in Reaction Wheel Assemblies (RWA), due to the patented architecture’s inherent advantages when used in flywheel applications. Because of the efficient, lightweight ironless core, zero-cogging stator, and high power-to-weight ratio, the TGR 60-30 offers more than double the torque of the closest competitor with minimal losses and no radial forces between the stator and rotor.

With more than two decades of experience in the design and production of slotless motor kits, ThinGap can leverage proven designs and analytical modeling that results in highly accurate transitions from predicted performance to real world operation. Furthermore, the process steps needed to produce motors of all sizes is highly scalable; ThinGap has shipped motors from 25 mm up to 600 mm in size.

Scheduled to launch early in the morning on February 6, 2024 from Kennedy Space Center aboard a SpaceX Falcon 9 rocket, the PACE Mission marks the first time ThinGap has achieved flight certification by NASA. PACE is a NASA mission that ThinGap has been proud to support. Developed and produced by NASA Goddard Space Flight Center in Maryland, PACE is a planned decade-long mission to study the Earth’s oceans and atmosphere.

The PACE launch is scheduled for 1:35 a.m. EST.  In attendance to witness the historic event firsthand will be representatives from ThinGap’s management and engineering teams.  In 2021, ThinGap supplied custom made LS Series motor kits to the development team at NASA Goddard.  These motors were designed to be integrated into the PACE Mission’s Ocean Color Instrument or OCI sensor payload.

The goal of the PACE mission is the monitoring of worldwide oceanic health through observation of the color of the ocean’s surface, as well as how reflected sunlight interacts with the atmosphere. The color of surface water is heavily influenced by sunlight’s interaction with chlorophyll, a green pigment found in plants as well as the phytoplankton that inhabit the ocean. Designed and built by NASA Goddard, the heart of the OCI (Ocean Color Instrument) is an advanced hyperspectral optical spectrometer, capable of measuring the color of the ocean from ultraviolet, through visible color, to short-wave infrared wavelengths. Previous NASA satellites have been limited to studying a small portion of this spectrum, so a single instrument being able to capture more data than before is a huge benefit to researchers. ThinGap supplied custom LS Series motors to NASA in 2021 that drive the continuously rotating cross-track telescope.

The two other payloads aboard PACE are polarimeters intended to measure how sunlight reflected by the Earth’s surface interacts with clouds, aerosols, and the ocean surface. The first is SPEXone, designed and built by a Dutch team including Airbus Defense & Space, Netherlands Institute for Space Research, and supported by the Netherlands Organization for Applied Scientific Research is designed to characterize particles suspended in the atmosphere by chemical composition and their impacts on climate change.

The other polarimeter aboard PACE, designed and built by University of Maryland Baltimore County’s Earth and Space Institute is HARP2 (Hyper-Angular Rainbow Polarimeter) sensor. HARP2 is a wide-angle imaging polarimeter designed to measure the properties of atmospheric particles, including their size, distribution, shape, and density. Previous HARP instruments have been flown on both airborne platforms as well as CubeSats, which helped influence the design of HARP2.

ThinGap is honored to support this mission by supplying custom motors, as well as achieving flight certification. Additionally, ThinGap has supplied more than 2,500 motor kits in support of a major commercial constellation, as well as US Space Force projects for prime customers.

Seventy percent of the Earth’s surface is covered in water. Whether for defense, industry or exploration, the demand of underwater systems, such as manned submersibles, Remotely Operated Vehicles (ROVs), and Unmanned Underwater Vehicles (UUVs) is a market that is expected to grow to more than $10 billion by the 2030s, according to Emergen Research.  These underwater platforms of all forms stand to leverage the benefits of ThinGap’s high efficiency motor kits. With critical functions such as robotic actuation and quiet, yet highly efficient propulsion, ThinGap’s motors continue to find a home in marine and subsea applications.

An emerging use for ThinGap’s brushless DC motors is marine propulsion. ThinGap motors are ideal for underwater direct drive thrusters because of a high torque-to-diameter ratio. ThinGap recently delivered a floodable motor assembly based off its LS Series to a defense customer for a UUV application. With no gearbox, there are no drivetrain losses, enabling lower assembly weight, increased torque, and greater reliability.

As a flooded motor, ThinGap’s stator has the added benefit of inherent cooling from the cold seawater.  In addition, the thin profile of the slotless stator architecture provides less fluid resistance than more traditional actuators.  Mechanically speaking, the ring architecture allows propulsion to be directly outside of the rotor (propeller), or inside (impeller). High motor efficiency, low-noise underwater thrusters are ideal for the fast growing ROV, UUV, and AUV market segments.

With more than two decades of experience in the design and production of slotless motor kits, ThinGap leverages its proven designs to deliver engineered solutions to support both commercial and defense applications underwater. With standard products ranging in size from 25 mm to 393 mm in outer diameter, ThinGap’s highly scalable motor technology can be modified to fit any environmental requirement.

Fourteen seconds. That is the amount of time that the crew of Apollo 13 was instructed by NASA’s Mission Control to fire their Lunar Lander’s descent engine to return their damaged spacecraft back to Earth. With the ailing spacecraft being 60-80 miles off-course, this was the critical “push” that the crew needed to correct their return trajectory. The inside of the command module was close to freezing due to most onboard systems being shut down to conserve energy, including the onboard digital timer. With the odds stacked against the crew, it was up to a mechanical backup to time the engine burn – – Astronaut Jack Swigert’s Omega Speedmaster wristwatch. While the availability of a backup seems so obvious as to be an afterthought, it was in fact a decision that had been qualified by NASA five years earlier.

Flight qualification is a process by which components intended for space are subjected to a variety of conditions intended to replicate the harsh environment outside the atmosphere, not limited to vacuum, temperature, and shock. These tests are designed to push systems to their very limits to ensure functionality, an achievement that ThinGap motors have accomplished in support of an upcoming NASA mission.  Qualifying anything for use in space, whether it be a ThinGap brushless DC motor or a commercially made Omega wristwatch, is an important and complex process.

The story of the watch that saved Apollo 13 began nearly a decade earlier, with Mercury-Atlas 8 in October 1962. In the early days of manned spaceflight, astronauts were not issued watches, and instead were permitted to wear their personal timepieces. For Mercury-Atlas 8, test pilot and astronaut Wally Schirra wore his Omega Speedmaster, beginning what became a long relationship between Omega Watches and NASA.

With America’s lofty goal of fulfilling recently assassinated President John F. Kennedy’s dream of landing a man on the Moon by the end of the 1960s, no detail was overlooked, including the astronauts’ watches. By the time NASA was ready to select a watch for the Apollo program in 1965, they issued a solicitation to a handful of watchmakers based off of astronaut feedback, with ultimately only three makers responding: Omega, Rolex, and Longines.

With the three brand of watches procured for evaluation, it came time to test them in the most scientific way possible… to destruction, with the following flight certification regiment having been pulled from historical documents:

1. 1. 1. High Temperature– 48 hours at a temperature of 160°F (71°C) followed by 30 minutes at 200°F (93°C). For the high temperature tests, atmospheric pressure shall be 5.5 psi (0.35 atm) and the relative humidity shall not exceed 15%.
      2. Low Temperature –Four hours at a temperature of 0°F (-18° C)
      3. Temperature Pressure Chamber – pressure maximum of 1.47 x 10exp-5 psi (10exp-6 atm) with temperature raised to 160°F (71°C). The temperature shall then be lowered to 0°F (-18°C) in 45 minutes and raised again to 160°F in 45 minutes. Fifteen more such cycles shall be completed.
      4. Relative Humidity –A total time of 240 hours at temperatures varying between 68°F and 160°F (20°C and 71°C, respectively) in a relative humidity of at least 95%. The steam used shall have a pH value between 6.5 and 7.5.
      5. Pure Oxygen Atmosphere –The test item shall be placed in an atmosphere of 100% oxygen at a pressure of 5.5 psi (0.35 atm) for 48 hours. Performance outside of specification tolerance, visible burning, creation of toxic gases, obnoxious odors, or deterioration of seals or lubricants shall constitute a failure. The ambient temperature shall be maintained at 160°F (71°C).
      6. Shock –Six shocks of 40g each, in six different directions, with each shock lasting 11 milliseconds.
      7. Acceleration –The test item shall be accelerated linearly from 1g to 7.25g within 333 seconds, along an axis parallel to the longitudinal spacecraft axis.
      8. Decompression –90 minutes in a vacuum of 1.47 x 10E-5 psi (10 E-6 atm) at a temperature of 160° F (71° C), and 30 minutes at a 200° F (93°C).
      9. High Pressure –The test item shall be subjected to a pressure of 23.5 psi (1.6 atm) for a minimum period of one hour.
      10. Vibration –Three cycles of 30 minutes (lateral, horizontal, vertical, the frequency varying from 5 to 2000 cps and back to 5 cps in 15 minutes. Average acceleration per impulse must be at least 8.8g.
      11. Acoustic Noise –130dB over a frequency range from 40 to 10,000 HZ, for a duration of 30 minutes.

As if the torturous and destructive test routine wasn’t enough, the watches were subsequently required to retain their accuracy within 5 seconds a day. The Speedmaster was the winner by default, with the Longines and Rolex having failed at the beginning of the first temperature test. Despite being the victor, the Speedmaster was still worse for wear, with all the luminous paint on the dial having crumbled off, yet its workings remained accurate to within an impressive 4 seconds a day.

The Omega Speedmaster has changed very little cosmetically since it’s 1957 introduction

The reasons for the Omega Speedmaster’s durability ultimately comes down to a simple, yet robust mechanical movement inside, as well as a rugged, yet elegant case that envelops it. Introduced in the late 1950s for use in motorsports, the Omega Speedmaster is a hand-wound chronograph (a watch with an integrated stopwatch function) with a minimalist black dial with white markings and protected by a domed bubble acrylic watch glass. The Speedmaster had become a favorite amongst pilots due to the highly reliability, legibility, and most importantly, the accuracy it possessed.

Ed White on a spacewalk during Gemini 4

With the Speedmaster now qualified for all manned space missions and extravehicular activities, they became standard issue to NASA’s crews.  In June 1965, Ed White wore his on the first American spacewalk during Gemini 4. When Apollo 11 landed on the Moon in July 1969, mission commander Neil Armstrong left his in the Lunar Lander to serve as a backup timer as the Lander’s internal electronic timer had malfunctioned. However, Buzz Aldrin chose to affix his for the moonwalk, making the Speedmaster the first watch worn on the Moon.

Buzz Aldrin in the Lunar Module ahead of lunar landing

Despite its previous widescale acceptance by the aeronautical community, the Speedmaster’s defining moment came during Apollo 13 in April 1970, after an exploded oxygen tank crippled the Apollo Lunar Module en-route to the Moon. With their vehicle critically damaged, making their lunar mission impossible, the astronauts agreed to forsake all creature comfort, and powered down all support systems, except for basic life support, including the digital mission timer to save power. Jack Swigert’s manual 14 second burn, timed on the watch, ensured that their freezing capsule re-entered the at the right angle, instead of their trajectory which would have bounced them off the Earth’s upper atmosphere and back into space.

Astronaut Jack Swigert during spacesuit fitment

The Speedmaster flew with NASA for the rest of the Apollo moon missions, and subsequent NASA programs. When Apollo-Soyuz, the first international space flight, flew in 1976, both the American astronauts and Soviet cosmonauts were seen wearing Speedmasters–an interesting detail given that cosmonauts had previously worn exclusively Soviet-made watches as a way to promote their domestic industry and were regularly worn aboard the Mir Space Station.

The Speedmaster was re-certified by NASA in 1978 for the Space Shuttle program, yet again undergoing the same rigorous regime. Through the Shuttle program, the Speedmaster remained standard issue for all astronauts, and in the 1990s, NASA and Omega collaborated on a clean-sheet watch, designed with the needs of modern astronauts in mind. This joint venture resulted in the Speedmaster X-33, which saw the purely mechanical watch upgraded to a modern, battery-powered computerized watch. Despite being superseded by a modern replacement, the original Speedmaster has still been seen worn aboard the International Space Station.

German Astronaut Alexander Gerst is seen wearing his Speedmaster X-33 aboard the International Space Station

To this very day, one can walk into a jeweler and buy a watch that is cosmetically and functionally identical to what has been flown since 1962. In fact, from the mid-1960s onward, the caseback of every Omega Speedmaster Professional (affectionately referred to as the Moonwatch) bears the inscription “Flight-Qualified By NASA In 1965 For All Manned Space Missions-The First Watch Worn On The Moon”.

1970s Omega print ads detailing the Speedmaster’s involvement with NASA and the Apollo program

ThinGap has supplied flight-qualified motors to NASA in support of their upcoming PACE mission. Focused on monitoring the overall health of worldwide oceans and atmosphere by monitoring the color of the seawater, PACE is set to launch in February 2024 from Kennedy Space Center. ThinGap is honored to support this mission by supplying custom LS Series slotless motors that drive the satellite’s primary sensor, the Ocean Color Instrument. Additionally, ThinGap has supplied more than 2,500 motor kits in support of a major commercial constellation.

Works Cited:

OMEGA and Apollo 13 – The 14 critical seconds between success and failure

NASA Testing Regime for the Omega Speedmaster Moonwatch

Apollo 13 — A Life-Saving Fourteen-Second Burn Timed With The Omega Speedmaster Professional

A Watch Made for Space but Ready for Anything

Actual Pictures Actually Showing The Speedmaster Professional Actually Being Used For EVA, Today (Well, In 2014)

Watches used in space exploration