To make a decision for or against a lifting device, you must know the advantages and disadvantages of a possible investment and weigh them up against each other. Depending on the area of application, an alternative machine may be better suited to perform a task than a standard lift table. In this article we will compare the lift table with four alternatives.
Pallet trucks, forklifts, cranes, lift tables and stacker cranes are probably the most likely equipment to be encountered in manufacturing and trading companies. For this reason, we have selected these five machines for comparison.
First, we will focus on general arguments for and against a scissor lift table. Followed by a short comparison with the alternatives.
If the operating conditions of the lift table are not very special, a simple design is sufficient. In the simplest case, it only consists of a platform, scissors and a base frame. Keeping the design to essential and common components has several advantages. For example, hydraulic scissor lift tables are generally regarded as a very inexpensive and low-maintenance means of conveyance.
A standard lift table with basic equipment can only be raised and lowered. So the controls and operation are correspondingly simple. Even when the functionality is extended by a rotating and/or tilting platform, there is hardly any risk of operator errors, as the operating elements are usually intuitively understood correctly. The short time required for the necessary instruction on how to use it can be seen as a further advantage of the simple operation.
In the case of complicated sequences, the control system can usually also be (partially) automated to completely eliminate the risk of operating errors and further rationalise the conveying process.
Most lift table manufacturers use modular systems for the production of scissor lifts . Often only the lift table platform is adapted to the customer's needs and requirements. This means that basically all desired platform geometries and load-handling device devices can be produced. One example is the lifting work table, where roller conveyors are often used.
In addition, the supporting structure can be stiffened relatively easily, so that even heavy loads can be lifted without any problems. Examples are special lift tables, which are able to lift up to 100 tons.
The range of functions of a simple lift platform can easily be extended by additional rotating and tilting platforms. Apart from these superstructures, mobile lift tables on rails or wheels are also part of the standard range of almost every manufacturer.
Some producers also have extensive experience in the field of special lift tables. These suppliers can cover almost all customer requests and requirements.
By equipping the lift table with an undercarriage, the lift platform becomes a mobile and flexible helper. However, no lift table currently on the market has the agility of a forklift.
If the lift table needs to be loaded with a pallet truck, it must be ensured that the platform can be driven on. This is achieved by means of special platform geometry, a pit or a ramp plate.
If the on-site conditions do not allow the use of lift table that is flush with the ground or floor, it will unfortunately not be possible to use special platform geometry to make it capable to drive on. The only remaining solutions are the pit and the drive-on wedge.
Pits have the disadvantage that the lift table can only be relocated at a higher cost: the old pit must be removed and a new pit constructed. A lift table recessed in the floor thus reduces the flexibility of the in-house production.
An alternative to the pit are ramp plates. These are often used for column lifts . However, ramps can take up valuable space.
Pallet trucks can be found in almost every company. They are inexpensive, flexible and therefore indispensable in production and goods handling.
However, their usability is limited to low to medium loads that can be accommodated on a Euro pallet. What weight can actually be transported and at what speed depends on the physical abilities and strength of the respective employee. Moreover, a good hall floor is a prerequisite for effortless operation. Differences in height are usually not surmountable with a pallet truck, making a stationary lift table a useful addition.
Overhead and gantry cranes are known for easy positioning and high travel speed. They can also handle heavy loads.
Their drawback is that they are very inflexible. They always require rails or a comparable guide system, especially for heavier loads. This guide system limits the place of use and the crane can only be relocated with great effort and expense. And the acquisition costs are also comparatively high.
Compared to lift tables, forklifts have a higher travel speed. Accordingly, valuable working time can be saved on long distances. A forklift is also very flexible. It can be used wherever it is needed. In addition, the functionality of the forklift can be easily extended with special attachments.
However, the high acquisition costs and the not inconsiderable maintenance costs are disadvantages. Compared to the space required by the conveyor, it also has a low load-bearing capacity. The maximum possible payload is also low compared to a lift table. This is due to the arrangement of the support structure. As this cannot be placed underneath the load, the forklift itself must have a correspondingly high dead weight to avoid the risk of tipping.
Also, it is difficult to have an overall view of the working area of the forklift, especially for inexperienced drivers, so that they often bump against gates and walls with the load or the vehicle.
Storage and retrieval machines can travel at very high speeds. In addition, the possibilities for accelerating and decelerating the operating units are fully maximised. This allows very fast and efficient material handling.
The use of a storage and retrieval machine is not profitable for a normal production plant. The acquisition and maintenance costs are only worthwhile when the material handling is very high and therefore often only for large mass producers or trading companies. Furthermore, the usual storage and retrieval machines are only designed for small and light loads. Accordingly, they are not suitable for bulky and heavy objects.
After these brief comparisons we would now like to see in which machine we should invest. The choice is quite clear ... no specific lifting device.
As always, the super-duper all-in-one do-it-all does not exist. Every means of conveyance has its strengths and weaknesses, its special place of application. So the responsibility for the right choice of machine lies with the decision maker or his advisors.