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What determines the quality of low-backlash gearboxes?

What determines the quality of a low-backlash gearbox? The production of low-backlash gearboxes is a very challenging discipline and success depends on several factors. We discuss these factors in this article, and we extensively discuss the effect of these elements on the final quality of the low-backlash gearbox.

The main factors determining the quality of low-backlash gearboxes are:

Know-how
Machinery
Facilities
Volume
Experience
Delivery time
Investment

Of course we are happy to explain why.

1. Know-how

This is also a difficult one, because it cannot be expressed in money. It is not for sale in that sense, but it is the most important. The know-how translates into the direction of the application and the servo motor as well; how do you manufacture something like that economically? Which materials, hardness, processing do you use and for which applications is the low-backlash gearbox designed?

A low-backlash gearbox is not a further development of “normal” gearboxes! If a supplier of low-backlash gearboxes also produces “normal” gearboxes, things often go wrong in practice.

2. Machinery

To make such low-backlash products, very accurate (gearing) machines are needed, and the most accurate gearing machines come from Germany, Switzerland or Austria. In addition, you also need CNC centers – preferably turning and milling in 1 setup – and high-precision grinding machines. Because you do not want to outsource the hardening, you also need a hardening line, if possible with different hardening principles. And before you send components to the assembly, you want to have measured – at least every batch – for dimensions and hardness. You can only measure toothing with a probe in a surface, contour and shape measuring machine. Here too, the German-made machines are leading. A typical delivery time for such a machine is more than a year.

3. Facilities

In addition to machines, you also need a building. This must be extremely vibration-free and fully air-conditioned. It is preferable to place the most accurate machines (including grinding and measuring machines) in a basement to minimize the influence of vibrations. After the raw material has arrived, it must first lie down for a while to acclimatize. The entire factory must be kept at a constant temperature to avoid dimensional deviations. As an example: Apex Dynamics’ most accurate rack has a deviation of 17 um/m. One degree of temperature deviation is already 12 um/m!

4. Volume

To make the idea of producing low-backlash gearboxes profitable, you need volume, and this requires years of marketing. Your product must be proven good if a machine builder wants to apply it and then export his machine to Brazil, for example. And it’s not just one gearbox you need, but a range of different build sizes and gear ratios and output shaft and backlash options. The fast running Apex Dynamics AF series already has 1737 versions, and that doesn’t include the angled variants!

5. Experience

It is of course a huge advantage if you have experience in the market for low-backlash gearboxes. Simply Reverse-engineering a gearbox with Cost-Down in mind is not going to work. Moreover, you do not know the specifications of the gearbox. Apex Dynamics had the experience of applying low backlash gearboxes for 10 years in the production of their Cartesian robots. (This branch is called Apex Robotics) That experience is the basis of the development and production – together with the instant volume – of the Apex Dynamics low-backlash gearbox. And only after years of being used in our own robots was this product transformed into a commodity.

6. Delivery time

Nowadays you cannot avoid having short delivery times in order to be successful. This means that you must have either entire gearboxes or all components in stock. Earlier we said that the AF series alone has 1737 versions, you should be able to deliver this all within a week or 2. And if you don’t have a component in stock, it is not economical to produce this one particle. In order to have a short delivery time, you must have a large warehouse at your disposal.

7. Investment

If you want to enter this market seriously, you need a huge capital for the building, machines, people for production, engineers, R&D and stock. In addition, you will also have to invest in a sales force: this product does not sell itself and the -often- online support is limited and stops after sales. And because the prices of low-backlash gearboxes are not that high, the question is whether you will ever have a return on the investment.

If you search the internet for manufacturers of low-backlash gearboxes, you will find a lot of them, and more than 90% of the hits come from China. On Alibaba, for example, it is questionable whether they are all manufacturers, mostly ther are resellers. These can also be quickly recognized by the specifications: this is often a 1 on 1 copy of the data sheet of Apex Dynamics’ gearboxes. Components (bearings, seals, lubricant) from well-known manufacturers are also often mentioned, but they are not used in the gearboxes.

But only 3 to 5 producers meet the above criteria and are therefore global players. Apex Dynamics is one of them that is still growing strongly in market share and we are very proud of that!

If you would like to know more about how APEX DYNAMICS deals with quality, please contact us.