Linear Slides

About Linear Slides and Linear Slide Manufacturers Including: Ball Bearing Slides, Dovetail Slides, Machine Slides, Roller Slides, Roller Tables & XY Tables.

Linear slides are precision products designed to turn motion or torque into thrust. They play a vital role in rolling motion applications. Linear slides are used to move mounted mechanisms across a given axis. Complete linear slides normally consist of at least a base, a saddle, adjusting screws and a straight gib. Linear slides can move loads consisting of lightweight miniatures to payloads of several hundred pounds. Linear slides are resistant to contamination, extremely durable in shock load conditions and run smoothly on lightweight frames.
 
Linear motion is basically movement in a straight line, from point A to point B. Linear motion is divided into speed and direction. That combination is called velocity. Linear motion is not typically used to actuate mechanisms, so it is often converted to other motion types. Many machines work by other kinds of motion, such as rotary motion. However, linear motion is often necessary in a process, making linear slides invaluable.
 
There are two principle types of linear slides. The most common variety is the ball bearing auto-slide. The other type of auto-slide uses crossed rollers. Linear slides assemblies use non-recirculating precision balls and rollers that move against highly polished and hardened rod ways, greatly reducing friction. When browsing through various linear slides, know for what applications the linear slides will be used. For immense loads and safe operation, dovetail linear slides will be appropriate. On the other hand, if a self-lubricating slide with a smaller maximum load carrying capacity is required, ball bearing slides, the most common linear slides, would be an appropriate choice.
 
Businesses that test computer floppy drives, do robotic welding and perform lots of transportation tasks use linear slides on a daily basis. These linear slides are also used in machine tools, instrumentation, gauging and positioning devices. The plastic and metal extrusion, printing, textile and glass manufacturing industries utilize linear slides. Linear slides are used in the medical and electronics industry because of the smoothness and quietness of the guide rollers. Linear slides are used in the wood/construction and packaging industries, as well, because of their durability. A complete linear slides system should be considered when assistance in straight-line work is needed.

Linear Slides Images Provided by Velmex, Inc.

Types of Linear Slides

• Ball bearing slides, also referred to as “ball slides,” are the most common type of linear slide because of their self-lubricating qualities, which increase their reliability. Ball bearing slides, which perform with a smooth linear motion, typically use four hardened and ground shafts that surround the balls at four different points.
  
• Crossed roller slides utilize rollers that crisscross each other and usually move between a group of four semi-flat and parallel rods, which surround them. The design of crossed roller slides allows them to carry up to twice the load of ball bearing slides and to absorb larger impacts.
  
• Dovetail slides are used in high load applications that require long travel distances and/or damping. Dovetail slides consist of a saddle or flaring tenon and a fixed base.
  
• Linear positioners consist of a drive that is attached to a fixed slide base and two extended springs that pull the slide top toward the screw end, against which it is firmly held. As the screw is turned clockwise, it moves the slide top forward along the linear axis, and because of the spring pressure, the screw retracts when turned counter-clockwise, resulting in a smooth linear rotation.
  
• Linear motor positioning stages are reliable single- or multi-axis mechanical systems that position a payload and consist of few components, including a linear motor, bearings, encoder, limit switches, cable carrier and bellows. Linear motor positioning stages move payloads vertically or horizontally without mechanical transmission devices and at varying rates of acceleration and speed.
  
• Machine slides are precision products used in CNC machining.
  
• Precision slides consist of a carrier, a base and ways fitted together with a gib and gib screws, which allow for adjustment to ensure accurate movement. Precision slides are basically motion guides that are used to feed and retract parts, tools or fixtures on all kinds of equipment.
  
• Roller slides use perpendicular rollers and have a higher load capacity than ball bearings.
  
• Roller tables are the quietest type of bearing table.
  
• Rotary stages rotate on an axis, typically positioned in the center, and provide rotary motion used in positioning and moving objects. Rotary stages are utilized to adjust the roll, pitch and yaw of objects, as opposed to linear stages, which position objects in space.
  
• Standard slides integrate roller or ball guides to permit the engineering of complete systems easily and with a minimum of assembly time.
  
• XY tables are composed of forcers and platens.

Linear Slides Terms

Actuator – A mechanism used for controlling or moving an object indirectly, as opposed to manually.
 
Auxiliary Carrier – An optional carrier for linear slides that increases the load capacity.
 
Axial Loading – A load with a force moving along a shaft or another type of axis.
 
Base Mount – To attach linear slides by either fastening directly to “T” slot nuts located in the slide base or by using the base mounting.
 
Bearing – A device whose support allows smooth, low friction motion between two loaded surfaces moving against each other.
 
Breakaway – The minimum amount of force or pressure needed to actuate movement of a device, such as a cable, cylinder or rotary actuator, through a complete stroke.
 
Carrier – A device attached to the linear slide, commonly with a bearing system, and responsible for supporting and moving the load.
 
Center of Gravity (COG) – A single point at which the weight of an object is most concentrated. The object would remain in equilibrium if supported at the COG.
 
Coefficient of Friction – A measurement of resistance of a single object sliding across another.
 
Dead Length – The part of a linear slide or band cylinder that is necessary for mechanisms and mounting. Dead length plus stroke length equals the total length of the linear slide or band cylinder.
 
Deflection – The amount of bend under a specific weight load.

Gib – A wedge-shaped piece of metal or wood designed to hold structural parts in place and/or provide a bearing surface.  

Inertia – The amount of resistance of an object to change velocity. If a linear slide has a large inertia, more torque will be required to move it.
 
Leadscrew – A device that changes rotary motion into linear motion.
 
Proximity Sensor – A device that senses the end of a stroke on a linear slide. Proximity sensors supply signal to any of various controllers.
 
Rotary Actuator – An actuator that provides rotational movement.
 
Rotor – The shaft on a rotary actuator that rotates on its own axis.
 
Shock Absorber – A device implemented with linear slides to decelerate heavy loads at high speeds.
 
Stroke Length – The distance the carrier and its load move on the linear slide.
 
Tenon – A finger-shaped projection that fits into a corresponding hole.
 
Torque – The twisting or turning force that produces rotation.