MST expand on their new pin system
Prowling around scrutinising a machine in forensic detail, observers could be forgiven for thinking that they were a pair of detectives at work inside a plant compound just off the A1 in north-east England.
But colleagues Nick Fagandini and Gordon Gunter, who work for Co. Durham-based MST, are on the look-out for tell-tale signs that a five-year-old mini-excavator would benefit from a new innovation from Scandinavia, which they are convinced could be a quick and simple fix to a perennial issue which affects a lot of heavy plant.
The duo are in the yard of Hewden Plant Hire, in Birtley, giving their mini-excavator fleet a thorough examination in search of pivot pins that require mending, as they believe they have the solution to ensure that any repair work is a one-off rather than a regular occurrence.
Their solution comes in the form of the Expander system, which is manufactured in Sweden and distributed exclusively in the UK by MST.
Regardless of greasing habits, pivot point lug holes are prone to continual wear and eventually need to be restored to their original diameter and tolerance. Traditional solutions to this problem tend to be costly and time-consuming and, ultimately, are only temporary, whereas the Expander system is said to offer a permanent fix.
‘When you put a new pin in a new hole you have to allow for a very slight tolerance,’ explained MST sales manager Gordon Gunter. ‘But unfortunately, with even the slightest of tolerances comes movement. From day one, the pin moves very slightly and that can cause the holes to open up.
‘However, if you put an Expander pin in, the pin locks into the hole and never moves. It completely eliminates the issue of holes opening up.’
MST believe the Expander pin, which comes with a 10-year guarantee, is ideal in the current difficult economic times, because it adds to the lifespan of heavy machinery and makes it far easier to maintain.
‘It’s very simple but very effective at the same time,’ commented Nick Fagandini, MST’s account manager for Expander. ‘Fundamentally, it’s a cost-saving device because it leads to a reduction in downtime, but it’s also a simple product – simple to identify, simple to order and simple to fit.’
The Expander system is a pivot-pin assembly for heavy equipment, which, according to its manufacturers, provides a superior means of resolving the issue of wear in pivot points.
The conventional method of constructing a pivot point involves inserting a pivot pin through two lug ears with a bearing housing in between. Typically, the lug holes are a few thousands of an inch larger than the pin diameter so that the pin can be inserted.
However, because the pin is generally made from a harder material than the lug ears, these begin to wear out and gradually enlarge the diameter of the hole.
Over time, the lug holes become so worn that the pivot becomes unstable, begins to break down and becomes a hazard in the working environment. Repairs to worn-out pivot points can be costly and require several days to complete.
According to Expander, the orthodox repair method requires welding and line-boring of the lug hole, yet this is only a temporary solution as further wear will occur. Indeed, many customers operate in work environments where this sort of repair is required several times a year.
With the Expander system, however, both ends of the pivot pin are tapered and an expansion sleeve is fitted at each end of the pin, followed by a washer and securing element. The assembly is installed in the pivot point and the securing elements are tightened.
As the elements are tightened, the expansion sleeves are forced over the tapered ends of the pin, creating pressure between the pin and the lug-ear and locking the Expander system into the pivot. As a result, pivot wear is permanently eliminated.
The standard sleeves expand up to 2mm, while standard oversize sleeves expand up to 4mm. A range of specialist oversize sleeves is also available.
According to MST, the key selling point of the product is that the Expander system solves pivot wear problems for good. Once the system has been installed, the machine is as good and as stable as new. Moreover, because the Expander is secured from both sides, it provides greater safety because the expansion sleeves cannot work loose, yet the system is easy to disassemble when a bushing or bearing needs to be replaced
For MST’s sales director, Rory Whitehall, the benefits of the Expander system are manifold, thanks to its technological innovations, which ensure less downtime for machines and make ordering a simple process via Expander’s own website and database. ‘It is so easy to fit this pin and forget about the worry of wear. That is the key to its success,’ he said.
