Sliding gate rack: features, types and recommendations on how to choose

1. What is a sliding gate gear rack
2. Types of gear racks
3. Module and dimensions
4. How to choose the rack for sliding gates
5. Installation guide
6. Maintenance tips
7. Frequently asked questions

Cantilever sliding gates are among the most popular entry systems in Europe and Ukraine. According to market data, over half of all automated gates in residential and industrial sectors are cantilever systems. Their popularity is due to space-saving installation, reliable operation, and ease of use. However, the proper functioning of such gates heavily depends on the quality and correct installation of the automatic system. One of the essential components in this setup is the gear rack, which enables the gate motor to open and close the gate leaf automatically.

This article explains what a gear rack is, the types available, the materials used, how to choose the right one for your gate, and how to install and maintain it correctly.

What is a sliding gate gear rack and what is its function?

Sliding gate gear rack — is a long linear element with a row of evenly spaced rack teeth, which is installed at the bottom, along the inner side of the leaf. It is an integral part of the mechanical transmission in the automatic system: the gate drive has a rotating drive gear, and it is the rack that converts this rotation into translational movement of the leaf. Thus, the rack acts as a transmission link between the motor and the gate.

When opening, the drive gear moves along the rack, «catching» on its rack teeth and pulling the door leaf sideways. When the motor rotates in the opposite direction, the gate closes. This principle of operation belongs to the classic rack-and-pinion mechanism, which is characterized by high reliability and efficiency even under heavy loads.

No automatic sliding gate can function without a rack. That is why it is important to choose a high-quality rack that is compatible with the gate parameters and the drive. As well as a suitable kit of hardware for sliding gates.

Types of gear racks

Gear racks are categorized by the material they are made from, their structural design, and intended use. The main types include:

1. Steel gear racks

Steel racks are the most common and durable solution. They are suitable for both residential and industrial gates, especially where high loads or frequent usage is expected.

Advantages:

• Long service life.
• High strength and rigidity.
• Excellent load capacity.
• Minimal deformation under stress.

Disadvantages:

• Heavier than other types.
• Slightly noisier operation.

2. Nylon coated steel gear racks

This is a modern compromise between weight and strength. Such racks have a steel inner base, which gives the structure rigidity, but the outer part is made of polyamide or other durable polymer. Such racks have a lower noise level during operation.

Advantages:

• Quiet operation.
• Resistant to moisture.
• Lighter than solid steel.

Disadvantages:

• Lower load capacity, not suitable for heavy gates.

3. Solid nylon (all-Polymer) gear racks

Made entirely of polymer, these are intended for lightweight residential gates with low opening frequency. Easy to install and quiet in operation, but not as strong or durable.

Advantages:

• Lowest cost.
• Minimal noise.
• Easy to install.

Disadvantages:

• Low rigidity and prone to deformation.
• Shorter lifespan.
• Low carrying capacity, not suitable for medium and heavy gates.

Gear rack module and dimensions

One of the main technical parameters of a gear rack is the rack teeth module. It determines which rack you need to choose for your drive. If these elements are not compatible in terms of module, the automatic system will simply not be able to operate — or will operate with increased wear and risk of breakdowns.

What is a rack teeth module?

Rack teeth module (M) — is a standardized gear parameter that determines the size of the teeth. Formally, the module is the ratio of the diameter of the gear's dividing circle to the number of teeth. But in the practice of gate installation something else is important: the module directly determines the tooth pitch on the rack, i.e. the distance between the same points (vertices) of two adjacent teeth.

The distance between the vertices (tooth pitch, p) is calculated using the formula:

p = π × M

where π ≈ 3.14, and M — tooth module in millimeters.

The most common modules for gate racks are:

How to identify your rack module::

1. Check the gate openers technical manual — the module is usually specified there.
2. Measure with a ruler or caliper — measure the distance between the three vertices (i.e. 2 steps) and divide it by 2. If you get ~12.6 mm, this is M4, ~18.8 mm is M6.
3. Compare with the gear — if the teeth of the rack match the teeth of the gear without any gaps or misalignment, the module is correctly matched.

Rack dimensions

The standard length of the toothed rack is usually 1000 mm (1 meter). To cover the full length of the gate opening, several sections must be installed. To determine the number of racks you need, measure the width of the driveway (gate opening) and add 1 m to this width (counterweight). For example, for a 2.5 m wide household gate, you will need 4 sections of a meter-long toothed rack. For a gate with a 3.5-4 m passage, 5 meters of rack will be required.

The width and height of the rack may vary depending on the manufacturer and its type, for example, M4 steel racks can be about 20-30 mm high and up to 10 mm wide.

How to choose the right gear rack?

The right choice of gear rack is the key to the long-lasting and safe operation of the entire automatic gate system. To find the right model, you need to consider several key factors:

1. Determine the weight and size of your gate. The heavier and longer the gate leaf, the stronger the rack should be. For gates up to 500 kg, you can choose a polymer or steel rack. Gates weighing more than 500 kg should be equipped with a steel rack.
2. Determine the tooth module, if you already have a drive. Because the rack module must exactly match the drive gear module of the drive. It must be specified in the drive's data sheet. Usually, for household gates (up to 1000 kg), it is M4. For industrial gates (1000-2000 kg) — M6.
3. Climatic conditions. It is important that the rack is not deformed at high and low temperatures — steel can withstand -30...-40°C, some polymers — only up to -10...-15°C.
4. Frequency of use. Household gates that have 2-10 cycles per day can work with both polymer and metal rack. If the gate is opened frequently 50+ times a day (for example, at an enterprise), choose steel racks, as they are more wear-resistant.

Gear rack installation: Step-by-step

The installation of the rack is a crucial part of installing automatic system for sliding cantilever gates. Even a high-quality rack will not work efficiently if it is installed with an axis violation or an incorrect gap. Proper installation ensures smooth operation, quiet running and long service life of the drive mechanism.

Here are step-by-step instructions on how to properly install a steel sliding gate gear rack:

1. Preparation. Make sure that the gate leaf is installed straight — without distortions and deflections. If the rack is mounted to a profile pipe, the fastening/welding points must be free of rust, paint, and dust.
2. Set the initial position of the rack. Install the electric drive on the foundation and fix it. Turn on the manual mode (gearbox unlock) to rotate the gear manually. Attach the first section of the rack with the bolt spacers (bolted fasteners) screwed to it to the gear from above so that the teeth are almost completely engaged, there should be a gap of 0.5-1 mm (to avoid excessive friction).

3. Fixing the first section of the rack. When the first section is positioned and the teeth are perfectly seated on the gear, the rack bosses (fasteners) are welded to the gates frame.
4. Install the following sections in stages.Each subsequent section should continue exactly the previous one, without shifting the teeth.
   • The gate is pushed forward manually to the length of the first section.
   • The second section of the rack is butted up against the first — preferably with a minimum gap (up to 1 mm).
   • Be sure to check the engagement at the joint: the teeth should not catch the gear or create a gap.
   • The section is welded and moved on to the next one.
5. Final setting and stroke check. After installing the entire length of the rack, it is necessary to fully roll the gate back and forth by hand to make sure that there are no jams, vibrations or gear jumps. If there is too much engagement in some areas, the rack is released and adjusted in height.
6. Fixation and protection of joints Weld seams should be cleaned with a grinder and protected with anti-corrosion paint. It is advisable to apply a layer of technical grease (lithol, graphite or silicone) to the surface of the teeth to reduce noise and wear.
7. End position adjustment and testing. After mounting the rack, the drive is connected, and the magnetic stopper limit switches are installed and adjusted.

Maintenance tips

A properly installed gear rack requires virtually no maintenance. However, it is recommended to extend the service life:

• Clean the rack regularly from dirt, ice and snow.
• Check the fasteners every few months and tighten the bolts if necessary.
• For steel racks, periodically lubricate the surface with a special grease if recommended by the manufacturer.

Frequently Asked Questions (FAQ)

1. How do I check rack compatibility with my motor?

You need to know the rack and gear module of the drive it supports. This information is provided in the technical documentation for the drive. For household gates, the M4 module is most often used — it is compatible with most drives.

2. Which gear rack should I choose?

We recommend a galvanized steel rack, as it is more resistant to deformation, more durable, does not rust and does not require additional protection — it is the best choice for outdoor installation.

3. Can I install the sliding gate rack myself?

Yes, if you have the right tools and basic skills in working with welding equipment. The main thing is to set the rack height correctly and ensure even engagement with the gear. However, we still recommend that the installation be carried out by specialists, who will take into account all the nuances of your gate and will be able to install the racks and other sliding gate hardware exactly.

4. What happens if the rack is installed unevenly?

An uneven rack causes noise, gate bouncing, or overloading of the drive. This can lead to premature wear of the gear, rack and drive.

5. How to distinguish a quality rack from a low-quality rack?

• In high-quality models, the module of the teeth, when mirroring two racks, fits almost completely into each other. In low-quality models, they do not fit into each other completely — because of this, the grip will be incomplete, because the contours of the module are not ideal.
• The edges of the teeth should have barely noticeable chamfers. Cheap ones have sharp edges because they have not been processed after the guillotine.
• The oval holes for fasteners should be even. In low-quality ones, cutting holes leads to a curvature of the bottom edge.
• The ends of the rack must be flat; cheap ones have metal deformation from the guillotine at the ends, which can make it difficult to mount the rack.
• The surface should be evenly matte. In cheap ones, it is roughly processed and sometimes damaged.

Sliding gate racks SP Premier

SP Premier racks are made of Q235 galvanized steel, which can withstand high loads, has good weldability and provides resistance to corrosion and wear. They are compatible with automatic system for all types of sliding gates, both domestic and industrial. Thanks to the precise geometry of the teeth, SP Premier racks ensure smooth running of the gate and reduce the load on the drive.

Ask about the SP Premier gear rack kit

 Phone: +38 050 357-75-74

 Viber: +38 050 357-75-74

 WhatsApp: +38 050 357-75-74

 Telegram: +38 050 357-75-74

 E-mail: info@sppremier.com

View the gear rack kit in the Catalog