The compact rail systems are unique. They have many major advantages over other rail systems.
The rails are easy to set up and can adjust for some misalignment of the structure on which it is being used. The compact rail system achieves this by using a master (T type) rail, and a slave (U type) rail. This allows the sliders in the T rail to remain fixed in place but allows lateral movement of the sliders in the U rail to adapt to any misalignment and avoid any issues of stiction.
Slave (U) rails have flat, parallel raceways that allow free lateral movement of the sliders. This flexibility can mean a large saving in the machining of the structure surface making it a very cost-effective solution.
Fast, smooth and quiet
The unique eccentric roller allows easy preload adjustment for smooth running. Very high speeds allowed, very quiet operation.
Dirt and debris resistant
The internal raceways are resistant to dirt and debris, larger roller bearings with seals and wipers are used (compared to small ball bearings on other systems).
Anti-corrosion option
Alloy coating or nickel plating of the rails and sliders can be applied to provide a corrosion resistant solution.
Rails can be easily joined together for unlimited rail lengths, and extra hole needs to be machined at the joint area. The rails need to be selected so they are “matched” and a joining tool needs to be used to align the rails.
Special purpose & packaging machines
Precision positioning systems
handling units
robotic systems • cutting machines
Seating
Sliding seats
disability ramps
seat extensions
Safety guarding
Extending protective systems
sliding gates
automatic pick & place
Sliding doors & windows
Internal sliding doors
gates • roof lights
display cases
Photography & lighting
Sliding tracks
positioning of lights
shielding systems
Medical technology
X-ray equipment
dental chairs
bed extensions
Food, drink & pharmaceuticals
Food handling conveyors
pharmaceutical factories
stainless display equipment
Transport (naval)
Sliding hatches
pull-out storage
Transport (rail)
Seat adjustment
sliding doors
battery removal units
Transport (automotive)
Ambulance sliding systems
fire fighting vehicles
sliding panels
Transport (military)
Sliding seats
protective hatches
stretcher extensions
T Rail (master)
Master rail
Accepts radial and axial loads
U Rail (slave)
Slave rail
Compensates for misalignment in one plane
Solid body, front mount - Type CL
Solid steel, zinc plated body
with removable end wipers
side seals, fixing in top face
Solid body, front mount - Type CS
Narrow body, solid steel
zinc plated
with removable end wipers
no side seals, fixing on top face
Solid body, side mount - Type CR
Solid steel, zinc plated body
with removable end wipers
side seals, fixing in side of body
Part no. | No. of rollers | Load capacities and moments
|
Side seal, front fixing
L1918.18CL-060 | 3 | 1540 | 825 | 262 | 1,6 | 4,8 | 8,3 | 8,3 |
L1918.18CL-080-A | 4 | 1540 | 825 | 310 | 2,9 | 7,1 | 8,3 | 24,9 |
L1918.18CL-080-B | 4 | 1540 | 825 | 310 | 2,9 | 7,1 | 24,9 | 8,3 |
L1918.18CL-100 | 5 | 1832 | 978 | 365 | 2,9 | 9,5 | 24,9 | 24,9 |
L1918.18CL-120-A | 6 | 1832 | 978 | 442 | 3,4 | 11,9 | 24,9 | 41,2 |
L1918.18CL-120-B | 6 | 1832 | 978 | 422 | 3,4 | 11,9 | 41,2 | 24,9 |
Side seal, top fixing
L1918.18CR-060-A | 3 | 1540 | 825 | 262 | 1,6 | 4,8 | 8,3 | 8,3 |
L1918.18CR-060-B | 3 | 1540 | 825 | 262 | 1,6 | 4,8 | 8,3 | 8,3 |
L1918.18CR-080-A | 4 | 1540 | 825 | 310 | 2,9 | 7,1 | 8,3 | 24,9 |
L1918.18CR-080-B | 4 | 1540 | 825 | 310 | 2,9 | 7,1 | 24,9 | 8,3 |
L1918.18CR-100-A | 5 | 1832 | 978 | 365 | 2,9 | 9,5 | 24,9 | 24,9 |
L1918.18CR-100-B | 5 | 1832 | 978 | 365 | 2,9 | 9,5 | 24,9 | 24,9 |
L1918.18CR-120-A | 6 | 1832 | 978 | 442 | 3,4 | 11,9 | 24,9 | 41,2 |
L1918.18CR-120-B | 6 | 1832 | 978 | 422 | 3,4 | 11,9 | 41,2 | 24,9 |
No side seal, front fixing
L1918.18CS-060 | 3 | 1530 | 820 | 260 | 1,5 | 4,7 | 8,32 | 8,2 |
L1918.18CS-080-A | 4 | 1530 | 820 | 300 | 2,8 | 7,0 | 8,2 | 24,7 |
L1918.18CS-080-B | 4 | 1530 | 820 | 300 | 2,8 | 7,0 | 24,7 | 8,2 |
L1918.18CS-100 | 5 | 1830 | 975 | 360 | 2,8 | 9,4 | 24,7 | 24,7 |
L1918.18CS-120-A | 6 | 1830 | 975 | 440 | 3,3 | 11,8 | 24,7 | 41,7 |
L1918.18CS-120-B | 6 | 1830 | 975 | 440 | 3,3 | 11,8 | 41,7 | 24,7 |
Part no. | No. of rollers | Load capacities and moments
|
Side seal, front fixing
L1928.28CL-080 | 3 | 4345 | 2213 | 652 | 6,4 | 16,4 | 28,0 | 28,0 |
L1928.28CL-100-A | 4 | 4345 | 2213 | 765 | 11,8 | 22,3 | 28,0 | 84,1 |
L1928.28CL-100-B | 4 | 4345 | 2213 | 765 | 11,8 | 22,3 | 84,1 | 27,2 |
L1928.28CL-125 | 5 | 5160 | 2630 | 919 | 11,8 | 30,0 | 84,1 | 84,1 |
L1928.28CL-150-A | 6 | 5160 | 2630 | 1102 | 14,1 | 37,3 | 84,1 | 140,0 |
L1928.28CL-150-B | 6 | 5160 | 2630 | 1102 | 14,1 | 37,3 | 140,0 | 84,1 |
Side seal, top fixing
L1928.28CR-080-A | 3 | 4345 | 2213 | 652 | 6,4 | 16,4 | 28,0 | 28,0 |
L1928.28CR-080-B | 3 | 4345 | 2213 | 652 | 6,4 | 16,4 | 28,0 | 28,0 |
L1928.28CR-100-A | 4 | 4345 | 2213 | 765 | 11,8 | 22,3 | 28,0 | 84,1 |
L1928.28CR-100-B | 4 | 4345 | 2213 | 765 | 11,8 | 22,3 | 84,1 | 27,2 |
L1928.28CR-125-A | 5 | 5160 | 2630 | 919 | 11,8 | 30,0 | 84,1 | 84,1 |
L1928.28CR-125-B | 5 | 5160 | 2630 | 919 | 11,8 | 30,0 | 84,1 | 84,1 |
L1928.28CR-150-A | 6 | 5160 | 2630 | 1102 | 14,1 | 37,3 | 84,1 | 140,0 |
L1928.28CR-150-B | 6 | 5160 | 2630 | 1102 | 14,1 | 37,3 | 140,0 | 84,1 |
No side seal, front fixing
L1928.28CS-080 | 3 | 4260 | 2170 | 640 | 6,2 | 16,0 | 27,2 | 27,2 |
L1928.28CS-100-A | 4 | 4260 | 2170 | 750 | 11,5 | 21,7 | 27,2 | 81,7 |
L1928.28CS-100-B | 4 | 4260 | 2170 | 750 | 11,5 | 21,7 | 81,7 | 27,2 |
L1928.28CS-125 | 5 | 5065 | 2580 | 900 | 11,5 | 29,0 | 81,7 | 81,7 |
L1928.28CS-150-A | 6 | 5065 | 2580 | 1070 | 13,7 | 36,2 | 81,7 | 136,1 |
L1928.28CS-150-B | 6 | 5065 | 2580 | 1070 | 13,7 | 36,2 | 136,1 | 81,7 |
Part no. | No. of rollers | Load capacities and moments
|
Side seal, front fixing
L1935.35CL-100 | 3 | 8200 | 3580 | 1080 | 13,1 | 34,3 | 62,7 | 62,7 |
L1935.35CL-120-A | 4 | 8200 | 3580 | 1240 | 24,3 | 44,1 | 53,7 | 161,2 |
L1935.35CL-120-B | 4 | 8200 | 3580 | 1240 | 24,3 | 44,1 | 161,2 | 53,7 |
L1935.35CL-150 | 5 | 9756 | 4260 | 1490 | 24,3 | 58,8 | 161,2 | 161,2 |
L1935.35CL-180-A | 6 | 9756 | 4260 | 1810 | 29,0 | 73,6 | 161,2 | 268,6 |
L1935.35CL-180-B | 6 | 9756 | 4260 | 1810 | 29,0 | 73,6 | 268,6 | 161,2 |
Side seal, top fixing
L1935.35CR-100 | 3 | 8200 | 3580 | 1080 | 13,1 | 34,3 | 62,7 | 62,7 |
L1935.35CR-120-A | 4 | 8200 | 3580 | 1240 | 24,3 | 44,1 | 53,7 | 161,2 |
L1935.35CR-120-B | 4 | 8200 | 3580 | 1240 | 24,3 | 44,1 | 161,2 | 53,7 |
L1935.35CR-150 | 5 | 9756 | 4260 | 1490 | 24,3 | 58,8 | 161,2 | 161,2 |
L1935.35CR-180-A | 6 | 9756 | 4260 | 1810 | 29,0 | 73,6 | 161,2 | 268,6 |
L1935.35CR-180-B | 6 | 9756 | 4260 | 1810 | 29,0 | 73,6 | 268,6 | 161,2 |
No side seal, front fixing
L1935.35CS-100 | 3 | 8040 | 3510 | 1060 | 12,9 | 33,7 | 61,5 | 62,7 |
L1935.35CS-120-A | 4 | 8040 | 3510 | 1220 | 23,9 | 43,3 | 52,7 | 161,2 |
L1935.35CS-120-B | 4 | 8040 | 3510 | 1220 | 23,9 | 43,3 | 158,1 | 52,7 |
L1935.35CS-150 | 5 | 9565 | 4180 | 1460 | 23,9 | 57,7 | 158,1 | 158,1 |
L1935.35CS-180-A | 6 | 9565 | 4180 | 1780 | 28,5 | 72,2 | 158,1 | 263,4 |
L1935.35CS-180-B | 6 | 9569 | 4180 | 1780 | 28,5 | 72,2 | 263,4 | 158,1 |
Part no. | No. of rollers | Load capacities and moments
|
Side seal, front fixing
L1943.43CL-120 | 3 | 12300 | 5520 | 1580 | 23,7 | 60,1 | 104,7 | 104,7 |
L1943.43CL-150-A | 4 | 12300 | 5520 | 1890 | 43,7 | 81,6 | 104,7 | 313,8 |
L1943.43CL-150-B | 4 | 12300 | 5520 | 1890 | 43,7 | 81,6 | 313,8 | 104,5 |
L1943.43CL-190 | 5 | 14680 | 6560 | 2220 | 43,7 | 108,7 | 313,8 | 313,8 |
L1943.43CL-230-A | 6 | 14680 | 6560 | 2650 | 52,5 | 136,0 | 313,8 | 523,0 |
L1943.43CL-230-B | 6 | 14680 | 6560 | 2650 | 52,5 | 136,0 | 523,0 | 313,8 |
Side seal, top fixing
L1943.43CR-120-A | 3 | 12300 | 5520 | 1580 | 23,7 | 60,1 | 104,7 | 104,7 |
L1943.43CR-120-B | 3 | 12300 | 5520 | 1580 | 23,7 | 60,1 | 104,7 | 104,7 |
L1943.43CR-150-A | 4 | 12300 | 5520 | 1890 | 43,7 | 81,6 | 104,7 | 313,8 |
L1943.43CR-150-B | 4 | 12300 | 5520 | 1890 | 43,7 | 81,6 | 313,8 | 104,5 |
L1943.43CR-190-A | 5 | 14680 | 6560 | 2220 | 43,7 | 108,6 | 313,8 | 313,8 |
L1943.43CR-190-B | 5 | 14680 | 6560 | 2650 | 52,5 | 136,0 | 313,8 | 523,0 |
L1943.43CR-230-A | 6 | 14680 | 6560 | 2650 | 52,5 | 136,0 | 313,8 | 523,0 |
L1943.43CR-230-B | 6 | 14680 | 6560 | 2650 | 52,5 | 136,0 | 523,0 | 313,8 |
No side seal, front fixing
L1943.43CL-120 | 3 | 12280 | 5500 | 1570 | 26,6 | 60,0 | 104,5 | 104,5 |
L1943.43CL-150-A | 4 | 12280 | 5500 | 1855 | 43,6 | 81,5 | 104,5 | 313,5 |
L1943.43CL-150-B | 4 | 12280 | 5500 | 1855 | 43,6 | 81,5 | 313,5 | 104,5 |
L1943.43CL-190 | 5 | 14675 | 6540 | 2215 | 43,6 | 108,6 | 313,5 | 313,5 |
L1943.43CL-230-A | 6 | 14675 | 6540 | 2645 | 52,0 | 135,8 | 313,5 | 522,5 |
L1943.43CL-230-B | 6 | 14675 | 6540 | 2645 | 52,0 | 135,8 | 522,5 | 313,5 |
The radial load that the sliders can take is significantly higher than the axial load, so where possible the rails should be set up with the sliders taking the loads in this plane.
One of the key benefits of the compact rail system is that it compensates for misalignment in the structure. This often results in a major cost saving when compared to the use of other guideways which have to be very accurately installed.
The compact rail system achieves this by using a master (T type) rail, and a slave (U type) rail. This allows the slides in the T rail to remain fixed in place but allows lateral movement of the sliders in the U rail to adapt to any misalignment and avoid any issues of stiction.
U rails have flat, parallel raceways that allow free lateral movement of the sliders. The maximum lateral movement for each size is shown in later tables.
It is acceptable (but not the preferred method), to use rails as below but the alignment accuracy needed is slightly greater and in this set-up only T type rails can be used.
In this case the axial load figure C0ax should be used in any calculations (which is considerably less than the radial load figure C0rad).
Most of the 3D models (in many formats) are available for download directly from our website www.automotioncomponents.co.uk
Please send us a sketch listing the main points of the application and our Technical Department will deal with this promptly. If required we can also arrange a visit to discuss the application and to show you the different systems available.
The compact rail systems have the following protective coatings as standard:
We can upgrade the anti-corrosion protection of the system by off ering the following:
CS type sliders type NI
Rail and screws
Typical horizontal application
For heavier loads
Standard slides
Arrangement 1
Arrangement 2
Arrangement 3
If delivered separately, or if the sliders need to be installed in another rail, the sliders must be re-adjusted. In this case, follow the instructions below.
The “•” or “V” marked on the slider indicates the direction of the fixed rollers.
The sliders have three (or more) large roller bearings. In general, the two at either end are fixed and the direction of these fixed rollers is marked on the sliders with a dot or an arrow.
Insert the sliders into the rails with the fixed rollers set to take the load in the best direction.
The middle roller is on an eccentric pivot that is easily adjusted (using the thin spanner that is supplied with them and a hexagon key). This allows the preload of the system to be set as required – stiff or free running.
Generally the sliders will not be inserted into the rails when leaving the factory. To set the sliders to the required preload is a simple procedure:
Size | Tightening torque Nm |
18 | 3 |
28 | 7 |
35 | 12 |
43 | 12 |
Manual rail clamps
Applications
Rail size | d1 | d2 | l1 | l3 | s | Tightening torque Nm |
18 | M4 x 0,70 | 8 | 8 | 2,0 | T20 | 3 |
28 | M5 x 0,80 | 10 | 10 | 2,0 | T25 | 9 |
35 | M6 x 1,00 | 13 | 13 | 2,7 | T30 | 12 |
43 | M8 x 1,25 | 16 | 16 | 3,0 | T40 | 22 |
Rail size | Screw type | l2 |
18 | M4 x 8 | 7,2 |
28 | M5 x 10 | 9 |
35 | M6 x 13 | 12,8 |
43 | M8 x 16 | 14,6 |
For counterbored type rails, these special low head profile screws are provided free with the rails.
If using an alloy plated rail then you should request nickel plated versions of these screws. Countersunk screws (for countersunk type rails) are not provided as they are readily available from many sources.
U rails have flat parallel raceways that allow free lateral movement of the sliders. The maximum axial off set that can be compensated for in each slider of the U rail is made up of the combined values S1 and S2 listed in the following table.
Considered from a nominal value Bnom as the starting point, S1 indicates the maximum off set into the rail, while S2 represents the maximum off set towards the outside of the rail.
Slider type | S1 | S2 | Bmin | Bnom | Bmax |
L1918.18CL/CS | 0,3 | 1,1 | 14,7 | 15,0 | 16,1 |
L1918.18CR | 0,3 | 1,1 | 14,7 | 15,0 | 16,1 |
L1928.28CL/CS | 0,6 | 1,3 | 23,3 | 23,9 | 25,2 |
L1928.28CR | 0,6 | 1,3 | 23,3 | 23,9 | 25,2 |
L1935.35CL/CS | 1,3 | 2,7 | 28,8 | 30,1 | 32,8 |
L1935.35CR | 1,3 | 2,7 | 28,8 | 30,1 | 32,8 |
L1943.43CL/CS | 1,4 | 2,5 | 35,6 | 37,0 | 39,5 |
L1943.43CR | 1,4 | 2,5 | 35,9 | 37,3 | 39,8 |
It is often the case that two T rails are used in the system design but where there are substantial alignment issues it is better to use a T (master) rail and a U (slave) rail as below.
This allows the slider in the T rail to remain fixed in the place, but allows some lateral movement of the sliders in the U rail to adapt to any misalignment and avoid any issues of stiction.
The application example in the following drawing shows that the T and U system implements a problem-free function of the slider even with an angled off set in the mounting surfaces.
If the length of the guide rails is known, the maximum allowable angle deviation of the surfaces can be determined using this formula (the slider in the U rail moves here from the innermost position S1 to outermost position S2):
The following table contains guidelines for this maximum angle deviation α, achievable with the longest guide rail from one piece.
Rail size | Rail length | Offset S | Angle α o |
18 | 2000 | 1,4 | 0,040 |
28 | 3200 | 1,9 | 0,034 |
35 | 3600 | 4 | 0,063 |
43 | 3600 | 3,9 | 0,062 |
The T and U system can be set up in diff erent arrangements. In the example below, a T rail accepts the vertical components of a load. A U rail attached underneath the component to be guided prevents the vertical panel from swinging and is used as moment support. In this way both a vertical off set in the structure, as well as possible existing unevenness of the support surface, are compensated for.
Linear accuracy is defined as the maximum deviation of the slider in the rail based on the side and support surface during straight line movement. The linear accuracy, depicted in the graphs below, applies to rails that are carefully installed using all screw holes onto a level and rigid structure.
Type | All rails |
Slider with equal arrangement | δL = 0,2 |
Slider with opposite arrangement | δL = 1,0 |
All | δS = 0,05 |
In the following deformation diagrams the total deviation of the linear guide is indicated under the eff ect of external loads P or moment loads M. As seen from the graphs, the rigidity can be increased by supporting the sides of the rails. The graph values indicate only the deformation of the linear guide, the supporting structure is assumed to be infinitely rigid. All graphs refer to sliders with 3 rollers and K1 preload (standard setting). An increased preload, K2, reduces the deformation values by 25%.
Radial Load
Axial Load
Moment Load
If a higher system rigidity is required, support of the rail sides is recommended, which can also be used as the reference surface. The minimum required support depth can be taken from the table.
Rail size | A | B |
18 | 5 | 4 |
28 | 8 | 4 |
35 | 11 | 5 |
43 | 14 | 5 |
Even the K and U system can be used in different arrangements. If the same example as with the T and U system is observed, this solution, in addition to the prevention of vibrations and moments, also enables the compensation of larger deviations in parallelism in the vertical direction, without negative consequences to the guide. This is particularly important for longer strokes as it is more difficult to obtain a correct vertical parallelism.
Individual slider under load moment Mz
When an overhanging load in an application with a single slider per rail causes an Mz moment in one direction, a 4 to 6 roller Compact Rail slider is available. These sliders are available in both configurations A and B in regards to the roller arrangement (to counter the acting Mz moment). The moment capacity of these sliders in the Mz direction varies significantly through spacing L1 and L2 in accordance with the direction of rotation of Mz. Especially when using two parallel rails, for example with a T+U system, it is extremely important to pay attention to the correct combination of the slider configuration A and B, in order to use the maximum load capacities of the slider.
The diagrams below illustrate this concept of the A and B configuration for sliders with 4 and 6 rollers. The maximum allowable Mz moment is identical in both directions for all 3 and 5 roller sliders.
If an overhanging load acts in an application with two sliders per rail and thus causes an Mz moment in one direction, there are diff ering support reactions with the two sliders.
For this reason, an optimal arrangement of different slider configurations to reach the maximum load capacity must be applied.
In practice this means, sliders with 3 or 5 rollers, both sliders are installed rotated by 180° so that the slider is always loaded on the side with the most rollers.
For an even number of rollers this has no effect.
The side mount slider with installation option from above or below cannot be installed due to the position of the rollers in reference to the installation side (therefore they are available in the configurations of both A and B).
Proper lubrication during normal conditions:
To reach the calculated service life, a fi lm of lubricant should always be present between the raceway and roller; this also protects against corrosion of the ground raceways.
The bearings inside the rollers are lubricated for life. Custom lubrication of the roller sliders for use in high temperature environments or in the food industry is available upon request. For more information, please contact our Technical Department.
The series sliders are provided with end wipers made of polyamide, to remove the contaminants on the raceways. Since the sliders do not have a self-lubrication kit, manual lubrication of the raceways is required. A guideline is to lubricate the raceways every 100 Km or every 6 months. We recommend a roller bearing lubricant with a lithium base of average consistency as a lubricant.
Lubricant | Thickening agent | Temperature range °C | Dynamic viscosity mPas |
Roller bearing lubricant | Lithium soap | -30° to + 170° | 4500 |
Sliders CL and CR are equipped with a safety system made of longitudinal sealing gaskets and rigid, spring preloaded wipers on both sides of the head for automatic cleaning of the raceways. The slider heads can be removed for replacement. To do this it is necessary to loosen the fittings, which should be re-fastened after installing the new heads with the following tightening torque:
Slider type | Tightening torque Nm |
Size 28 | 0,4 - 0,5 |
Size 43 | 0,6 - 0,7 |
The C series sliders are provided with end wipers made of polyamide, to remove the contaminants on the raceways. Since the sliders do not have a self-lubrication kit, manual lubrication of the raceways is required. A guideline is to lubricate the raceways every 100 Km or every 6 months. We recommend a roller bearing lubricant with a lithium base of average consistency as a lubricant.
Lubricant | Thickening agent | Temperature range oC | Dynamic viscosity mPas |
Roller bearing lubricant | Lithium soap | -30° to + 170° | 4500 |
Rail size | Alignment fixture |
L1918.AT18 | AT 18 |
L1928.AT28 | AT 28 |
L1935.AT35 | AT 35 |
L1943.AT43 | AT 43 |
Rail size | Alignment fixture |
L1943.AK43 | AK 43 |
The factory installed systems, consisting of rails and sliders, are available in two preload classes:
The excess is the distance between the contact lines of the roller pins minus y. This coefficient Y is used in the calculation formula for checking the static load.
Preload class | Excess* | Rail Size | Reduction Y |
K1 | 0,01 | all | - |
K2 | 0,03 | 18 | 0,1 |
The unique design of the Compact Rail product family enables the application of a partial external preload on selected locations along the entire rail.
An external preload can be applied by pressure along the side surfaces of the guide rail according to the drawing below. This local preload results in higher rigidity only at the locations where it is necessary (e.g. on reversing points with high dynamic forces).
This partial preload increases the service life of the linear guide by avoiding a continually increased preload over the entire length of the rail. Also the required drive force of the linear slider in the non-preloaded areas is reduced.
The amount of the externally applied preload is determined using two dial indicators to measure the deformation of the rail sides. These are deformed by thrust blocks with pressure screws. The external preload must be initially applied when the slider is not directly located in the pressure zone.
Rail size | L1 |
18 | 40 |
28 | 55 |
35 | 75 |
43 | 80 |
Frictional resistance
The drive force required for moving the slider is determined by the combined resistance of the rollers, wipers and seals.
The surface machining of the raceways and rollers have a minimal coeffi cient of friction, which remains almost the same in both the static and dynamic state. The wiper and longitudinal seals are designed for an optimum protection of the system, without a significant negative effect on the quality of motion.
The overall friction of the compact rail also depends on external factors such as lubrication, preload and additional forces. The following table contains the coefficients of friction for each slider type (for CS and CD sliders no friction occurs to μs).
Size | Roller friction μ | Wiper friction μw | Friction of longitudinal seals μs |
18 | 0,003 | 0,0015 | |
28 | 0,003 | ||
35 | 0,005 | ||
43 | 0,005 |
The values given in the above table apply to external loads, which, with sliders with three rollers, are at least 10% of the maximum load rating. For calculating the driving force for lower loads, please contact our Technical Department.
The minimum required drive force for the slider is determined with the coefficients of friction and the following formula:
Example calculation:
If an NTE43 slider is used with a radial load of 100 Kg, the result is μ = 0,005 (from table); and from the formula the following is calculated:
Therefore the minimum driving force for this example:
The radial load capacity rating, C0rad,the axial load capacity rating C0ax, and moments loads Mx, My, Mz indicate the maximum permissible values of the load.
Higher loads will have a detrimental effect on the running quality.
A safety factor, S0, is used to check the static load, which takes into account the basic parameters of the application:
Conditions | Safety factor S0 |
No shock or vibration, smooth and low-frequency reverse, high assembly accuracy, no elastic deformations | 1 - 1,5 |
Normal installation conditions | 1,5 - 2 |
Shock and vibration, high frequency reverse, significant elastic deformation | 2 - 3,5 |
The ratio of the actual load to maximum permissible load may be as large as the reciprocal of the accepted safety factor, S0, at the most.
The above formulae are valid for a single load case.
If two or more forces are acting simultaneously, please check the following formula:
P0rad = effective radial load
C0rad = permissible radial load
P0ax = effective axial load
C0ax = permissible axial load
M1 = effective moment in the X-direction
Mx = permissible moment in the X-direction
M2 = effective moment in the Y-direction
My = permissible moment in the Y-direction
M3 = effective moment in the Z-direction
Mz = permissible moment in the Z-direction
y = reduction due to preload
The safety factor S0 can lie on the lower given limit if the occurring forces can be determined with sufficient precision.
If shock and vibration are present, the higher value should be selected. For dynamic applications a higher safety level is required.
Example formulae for determining the forces on the most heavily loaded slider
The parameters in the formulae are shown below.
Static test
Static test
Note: Its defined that slider number 4 is always located closest to the point where the force is applied.
Static test
Static test
Test with a moving element of the weight-force Fg at the instant the direction of movement changes:
F = effective force (N)
Fg = weight-force (N)
P1, P2, P3, P4 = effective load on the slider (N)
M1, M2 = effective moment (Nm)
m = mass (Kg)
a = acceleration (m/s2)
The dynamic load capacity C is a conventional variable used for calculating the service life. This load corresponds to a nominal service life of 100 Km. For values of the individual slider see Load Capacities. The following formulae link the calculated theoretical service life to the dynamic load capacity and the equivalent load:
Lkm = theoretical service life in Km
C = dynamic load capacity in N
P = effective equivalent load in N
fc = contact factor
fi = application coefficient
fh = stroke factor
The equivalent load P corresponds in its effects to the sum of the forces and moments working simultaneously on a slider. If these different load components are known, P results as follows:
Here the external loads are assumed as constant in time. Brief loads, which do not exceed the maximum load capacities, do not have any relevant effect on the service life and can therefore be discounted. The contact factor fc refers to applications in which several sliders pass the same rail section. If two or more sliders move over the same point of a rail, the contact factor according to the table would be taken into account in the formula for calculation of the service life.
Number of sliders | 1 | 2 | 3 | 4 |
fc | 1,00 | 0,80 | 0,70 | 0,63 |
The application coefficient fi takes into account the operational conditions in the service life calculation. It has similar significance to the safety factor S0 in the static load test. It is calculated as described in the following table:
Conditions | Application coefficient fi |
Neither shocks or vibrations, smooth and low-frequency direction change; clean operating conditions; low speeds (<1m/s) | 1,0 - 1,5 |
Slight vibrations, average speeds (1 - 2.5 m/s) and average frequency of direction change | 1,5 - 2,0 |
Shock and vibration, high speeds (>2.5 m/s) and high-frequency direction change; extreme dirt contamination | 2,0 - 3,5 |
The stroke factor fh takes into account the higher load of the raceways and rollers during short strokes on the same total length of the run. The corresponding values are taken from the following graph (for strokes longer than 1m, fh = 1):
Size | Chamfer |
18 | 0,5 x 45° |
28 | 0,6 x 45° |
35 | 0,5 x 45° |
43 | 1,0 x 45° |
The low profile screws for counterbored holes are used with rails identified by T-C, U-C or K-C. The cylindrical screw allows some play in the countersunk fixing hole, so that an optimum alignment of the rail can be achieved during installation.
The area T is the diameter of the possible off set, in which the screw centre point can move during the alignment. The minimum chamfers on the fixing threads are listed in the table above.
Rail size | Area T |
18 | Ø 0,4 |
28 | Ø 0,8 |
35 | Ø 1,0 |
43 | Ø 1,2 |
These rails are identified by T-V, U-V or K-V. The selection of rails with 90° countersunk holes requires the precise alignment of the threaded holes for installation. Here the complex alignment of the rail to an external reference is omitted, since the rail aligns during installation by the self-centering of the countersunk screws on the machined hole pattern.
The slides have three or more large roller bearings. In the case of a standard three roller bearing slider, the two at either end are fixed and the direction of these fixed positions is marked on the sliders with a dot or an arrow. Insert the sliders in the rails with the fixed rollers set to take the load in the best direction.
The middle roller is on an eccentric that is easily adjusted using the thin spanner that is supplied with the sliders. This allows the preload of the system to be set as required - either stiff or free running.
Generally the slider will not be installed into the rails when leaving the factory. To set them to the required preload is a simple procedure:
Slider size | Tightening torque Nm |
18 | 3 |
28 | 7 |
35 | 12 |
43 | 12 |
The T type rails can be installed in two positions relative to the external force. For axial loading of the slider, the load capacity is reduced because of the decline in contact area caused by the change in position. Therefore, the rails should be installed where possible in such a way that the load of the rollers acts in the radial direction.
For critical applications with vibrations or a higher demand for rigidity, a support of the rail is beneficial.
This reduces the deformation of the rail sides and the load on the screws. The installation of a rail with countersunk holes requires an external reference for alignment. This reference can also be used as a rail support if required. All information in this section on alignment of the rails, refers to rails with cylindrical countersunk holes. Rails with countersunk holes self-align using the specified fixing hole pattern.
Rail installation 1
Rail installation 2
Rail installation 3
Screw type | Rail size | Tightening torque Nm |
M4 | 18 | 3 |
M5 | 28 | 9 |
M6 | 35 | 12 |
M8 | 43 | 22 |
If two T rails or a T and U system are installed, the height difference of the two rails must not exceed a certain value, in order to ensure proper guiding. These maximum values result from the maximum allowable twisting angle of the rollers in the raceways. These values account for a load capacity reduction of 30% on the T rail and must be carefully observed.
Size | α |
18 | 1,0 mrad (0,057°) |
28 | 2,5 mrad (0,143°) |
35 | 2,6 mrad (0,149°) |
43 | 3,0 mrad (0,171°) |
Example:
NTE43: if a = 500 mm
b = a*tanα = 1,5mm
When using two T rails, the maximum parallelism deviation must not be exceeded.
Otherwise stresses can occur, which can result in a reduction in load capacity and service life.
Size | // |
18 | 0,03 |
28 | 0,04 |
35 | 0,04 |
43 | 0,05 |
For parallelism problems, it is recommended to use a T and U or K and U system, since these combinations compensate for inaccuracies. K1 is the standard slider preload, K2 is the increased preload setting where extra rigidity is required.
Parallel installation 1
Parallel installation 2
Parallel installation 3
When using a two-track parallel linear guide system we recommend the use of a master/ slave rail system. The combination of T and U rails for compensating of deviations in parallelism or the K and U system to compensate for deviations in parallelism in two planes.
Installation step 1
Installation step 2
Installation step 3
If long guide rails are required, two or more rails can be joined to the desired length. When putting guide rails together, be sure that the register marks shown below are positioned correctly.
General information
Each rail has a one piece maximum length. Longer lengths are achieved by joining two or more rails together (joined rails).
We then machine the rail ends at a right angle to the end face and mark them. Additional fixing screws are included with the delivery, which ensure a problem-free transition of the slider over the joints, if the following installation procedures are followed. Two additional threaded holes are required in the load-bearing structure. The alignment tool for aligning the rail joint should be ordered (see below).
Rail size | l1 | Threaded hole (load bearing structure) | l2 | Alignment tool |
18 | 7 | M4 | 8 | L1918.AT18 |
28 | 8 | M5 | 10 | L1928. AT28 |
35 | 10 | M6 | 13 | L1935. AT35 |
43 | 11 | M8 | 16 | L1943. AT43 |
K43 | 11 | M8 | 16 | L1943. AK43 |
After the fixing holes for the rails are made in the load-bearing structure, the joined rails can be installed according to the following procedure:
Installation of joined rails step 1
Installation of joined rails step 2
Installation of joined rails step 3
Installation of joined rails step 4
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