Chapter 4.3: Guide Rail Types

4.3.1 Guide Rail Types Overview

Guide rail types mainly differ in their mounting method, which also determines the closure options for fixing holes. In addition, there are different fixing hole spacings and hardness characteristics. The following table provides an overview of MONORAIL MR roller and MONORAIL BM/BZ ball types. For available sizes, please refer to the SCHNEEBERGER MONORAIL and AMS product catalog.

MR Guide Rail Product Overview

BM Guide Rail Product Overview

4.3.2 Guide Rail Selection Criteria

Mounting Method

There are two main mounting methods for guide rails. Standard guide rails -N- and cover strip guide rails -C- have continuous fixing holes for mounting from above. N-type guide rail fixing holes can be closed with plastic plugs, brass plugs or steel plugs.

There are also guide rails with threaded fixing holes on the bottom for mounting from below. These guide rails are marked with the -NU- suffix.

The -D- suffix in the model description indicates fully hardened guide rails, -X- indicates rack guide rails for ball bearings (BZ).

Note: ● = Applicable

Side mounting represents the fourth variant, used for the MONORAIL BZ rack system. Because these lateral fixing holes are not located inside the carriage's area of movement, closing them is not essential (plastic plugs BRK can be used if required). The fixing holes for the connecting screws between guide rail and rack are closed at the factory with plastic plugs in the standard design.

Standard guide rail lengths

The standard guide rail lengths for MONORAIL MR and BM are:

L3 = n · L4 − 2 mm

for MONORAIL BZ:

L3 = n · L4

L3 rail length (mm)  n = 3, 4, 5…  L4 fixing hole pitch (mm)

Guide rails in special lengths

In case of deviations from the standard guide rail lengths set out above, the guide rail length for MONORAIL MR and BM can be calculated using the following formula:

L3 = n · L4 + L5 + L10

L3 rail length  n = 3, 4, 5…  L4 fixing hole division  L5 initial fixing hole spacing  L10 end fixing hole spacing (all mm)

In so doing, the following values should be observed for the initial fixing hole spacing L5 and the end fixing hole spacing L10:

L5max, L10max = L4 − (F2/2 + 1 mm)
L5min, L10min = F2/2 + 1 mm

F2 counterbore diameter (mm)

In the case of MONORAIL BZ, the following set values apply for L5 and L10:

L5 = L10 = L4/2

Surface hardness

As standard the side surfaces and tracks of the MONORAIL guide rails are inductively hardened. These guide rails are recommended for normal applications, for large-scale system lengths and if fixing holes need to be incorporated into the guide rail retrospectively, e.g. for pins or for fastening bellows.

In the event that a hardened guide rail upper surface is required, e.g. to support shoes for covers or because the guide rails are being used in an open machining area, through hardened variants are also available. In ND, NUD and CD types, the "D" stands for through harDened.

Guide rail cover

Depending on the type of guide rail, the guide rail fixing holes can be closed in different ways. For this purpose SCHNEEBERGER offers a variety of components for each specific application. The following tables give an overview of the variants on offer and their specific characteristics.

● = applicable  * U-type rail = fastening from below, no rail cover required