Advancements in load capacity, life and ease of manufacture allowed an ever-widening range of applications to benefit from nearly friction free linear guidance. Since the introduction of the square, or profile rail, linear guide in the 1970s, the design engineer has been faced with the pivotal question: round or square?

The efficiency of your linear ball bushing bearings depends largely on how well it is mounted into your machine or device. Watch this video for tips and accessories to help you properly mount your linear bearings.

Thread depths varied from maker to maker, but the proper A-B-C distinction lies not in the total thread depth but in the distance from the flange seat of the lens barrel to the innermost thread. The C-mount eventually became the standard mount for higher-quality amateur 16mm cine cameras.

After selecting shafting for your linear motion design, linear ball bushing bearings are next. An open or closed bearing will depend on the type of shafting you chose.

Meanwhile, the image circle of many lenses is unlikely to cover the entire area of the image sensor without serious vignetting since 16mm frame size is smaller than a µ4/3 sensor. Especially wide-angle C-mount lenses covering the whole sensor are very rare. The C-mount enthusiast will have to crop many images and videos shot with C-mount lens.

For most manufacturers, the financial cost of machine downtime can be significant, resulting in the loss of thousands or even millions of dollars. Small investments in routine and preventive maintenance, however, can pay off many times over.

How to choose between the main types of linear technologies, and how to design automation systems that deliver optimal performance using design requirements, rather than cost, as the primary consideration in selecting linear components.

Linear bearings

Cine cameras were often equipped with superb C-mount optics made by renowned lens makers like Kern, Taylor-Hobson, Dallmeyer, Meyer, Angénieux, Elgeet, Berthiot, and Schneider. Wollensak and Kodak also made some fine cine lenses. Video camera C-mount lenses were made for example by Canon and Fuji. Survey lens makers and industry lens makers are Fujian, Rainbow, Computar, Tamron and Pentax (Cosmicar brand).

The formats APS-C and even µ4/3 are not the ones which were and are in the focus of C-mount lens development. The maximum sensor size of survey cameras is smaller: 1 inch. That's more than 16mm film's 1/2" diagonal, so that several old 16mm movie lenses have a smaller image circle than 1". On the other hand there are survey lenses offered especially for 1" format, and some lenses for 2/3" format with longer focal lengthes may give a 1" image circle too. Thus system cameras with 1" sensors are more convenient concerning sufficient image circle or vignetting of adapted C-mount lenses.

LinearBearing Rail

Thomson provides extensive online resources to help you no matter where you may be in the Ball Bushing Bearing purchase decision process:

LinearBearing Block

Cheap C-mount adapters are available for the Nikon 1 cameras, but with those gadgets You get your MF lenses only utilisable in M mode of the camera. That means: in manual exposure setting mode. An alternative camera is the Samsung NX mini, but mechanical adapters aren't cheap, only made by one American maker. Of course these adapters enable convenient lens use in A mode, that means aperture priority with automatic exposure time setting, and that means all what C-mount adapters for µ4/3 mount deliver too. But they are not always available. For users of only small C-mount lenses the maker offers a CS mount adapter for the NX mini to which a light C-mount lens easily can be adapted, by means of a 5mm C-mount lens tube extension or a similar C/CS-mount adapter.

For most manufacturers, the financial cost of machine downtime can be significant, resulting in the loss of thousands or even millions of dollars. Small investments in routine and preventive maintenance, however, can pay off many times over.

But the Nikon 1 system is not out of the game: A chipped adapter can simulate the presence of a system lens so far that automatic shutter speed setting will be usable, too. Of course this adapter isn't cheap, too, since only available from one Russian maker. Thus, both options, either a Nikon 1 camera or the Samsung NX mini, might work conveniently as C-mount-adapting camera, but both for an adapter price that, shipment included, might cost nearly as much as a used camera body.[1]

LinearGuide Rail

Advancements in load capacity, life and ease of manufacture allowed an ever-widening range of applications to benefit from nearly friction free linear guidance. Since the introduction of the square, or profile rail, linear guide in the 1970s, the design engineer has been faced with the pivotal question: round or square?

For applications in which heavy loads require linear motion with speed, precision and no friction, Linear Ball Bushing® Bearings provide an optimal solution.

Similar new CSC lens mounts which followed like the Sony NEX, Nikon CX, Pentax Q or EOS M mounts allow C-mount lens adaption too. Lens adaptors are widely available except for Samsung's mount.

Thomson offers the world's largest selection of state-of-the-art linear bearings. Choose from several families of inch or metric linear bearings and accessories to meet your specific design needs, including our Super Smart Ball Bushings, which offer load capacities up to 7760 lb. When used with RoundRail linear guides, the inherent self-aligning-in-all-directions design of these linear bearings allows for ultra-smooth travel when mounted to wider-toleranced prepared surfaces. When used with Thomson 60 Case® shafting, our linear bearings last up to 50% longer than conventional bearings.

From shafting and supports, to round and square rail guides, linear motion systems to pillow blocks, Thomson demonstrates how our products excel as the best solution in a wide array of industrial applications.

In this century, people have begun to experiment with C-mount lenses on digital (still) cameras, a trend boosted by the launch of the Micro Four Thirds (µ4/3) cameras which have an appropriate flange/sensor distance to allow adaption of the 16mm cine lenses.

Available in metric or inch sizes, state-of-the-art Thomson universally self-aligning linear slide bearings have been manufactured to the highest quality standards for smooth, accurate motion for the past 75 years. And when used with Thomson 60 Case® LinearRace® shafting, travel life and load capacity are significantly increased compared to conventional models.

Linearguide Rail Canada

Heavy dutyLinear Sliderails

The "C" designation derives from the evolution of the mount from its "A" and "B" predecessors. All shared the same thread and diameter, but had different mounting depths; the three are not interchangeable. A-mount and B-mount lenses were used primarily on Filmo cameras of Bell & Howell. The cine camera and lens maker began to feature interchangeable lenses earlier than its concurrents like Victor. The first C-mount camera was the Bell&Howell's Filmo 70 for 16mm film.

The C-mount consists of a one-inch diameter cylinder threaded to a pitch of 1/32-in, or 32 threads per inch. It was designed specifically for lenses used on 16mm cine cameras. However, a small number of subminiature still cameras have been made using the same lenses, including the Schatz Sola, Optikotechna Mikronette and the Doryu pistol-shaped police cameras.

In your linear motion applications, adjustable diameter linear ball bushing bearings can help you achieve higher precision.

Some of the better quality cameras had a turret with a capacity for two or more lenses for making rapid changes in focal length. Though zoom lenses were available in the 1940's, they were very expensive and involved some optical compromises, so were not widely used until they had achieved better and more consistent quality at lower prices. After this was achieved, they eventually came to replace the turret in the 1960's, particularly in cameras for the amateur film maker. The C-mount zoom lenses became dominating when some professional and amateur video cameras with C-mount appeared.

Linear slide bearingsprice

How to choose between the main types of linear technologies, and how to design automation systems that deliver optimal performance using design requirements, rather than cost, as the primary consideration in selecting linear components.

Thomson currently has two account systems - one for the website and CAD model downloads, and one for e-commerce. We understand that two logins is an inconvenience and are working to consolidate our systems into one login process. Until we’re able to consolidate the two logins, please follow these guidelines:

When your design requirements call for something outside of the standard Thomson offering, it’s no problem. Our experienced support team can work with you to create the optimal solution for your application. Our custom bearing options include factory installed pillow block configurations, precision balls (corrosion-resistant, stainless steel, nylon and many more), factory lubrication and special finishes.

Linear slide bearingscatalogue

When video camera design evolved to modern camcorder design the interchangeable lenses vanished, but a few C-mount lenses are still produced for the market of surveillance cameras and industrial process control cameras.

Some think the older uncoated lenses may be more satisfactory for bokeh experiments, but a cheap "TV lens" for survey cameras may surprise positively too. Zoom lenses made for C-mount are a bit bulky and heavy but may be attractive for videographers who use for example a Panasonic Lumix GH µ4/3 camera since many C-mount zoomers are much faster than the original CSC zoom lenses.

For maximum capacity, linear bearings are oriented so the load is distributed between load bearing tracks. Watch this video to learn why this is so important to linear bearing performance, and, in turn, your machine designs.

An issue may be the lens' back when it is longer than its C-mount thread. For example Sony TV-lenses or Rainbow industrial process control lenses might not fit in µ4/3 cameras. Another issue are survey camera lenses for the similar CS-mount which are made for a shorter flange/sensor distance and smaller image size. On C-mount they can make only macro images which must be cropped.

To provide better service to you on our websites, we and our service providers use cookies to collect your personal data when you browse. For information about our use of cookies and how to decline them or turn them off please read our cookie policy [available here].