Lower investment volume, adequate production capacity – the arguments for buying a second-hand machine are obvious. Is it that simple though? Particularly in the case of complex tube/pipe bending machines, there is a whole range of factors determining the efficiency of using a second-hand system. In the worst case, the new, second-hand machine becomes a “failure” in the production sequence because the component quality and output performance do not match.
Who buys a car without a test drive and without knowing its features? Yet, investment in a second-hand system resembles precisely this scenario more often than you would think. This is particularly true if complex tube bending machines from a niche area are bought without consulting the original manufacturer.
Pipe bending processing on an industrial scale is a good example of this: customer-specific system solutions are used in many sectors, ensuring high-precision bending results by means of CNC control, high performance drives and bending tools with a complex structure. The sophisticated plant technology cannot be simply dismantled and reconstructed to produce new components in a different company.
“Detailed questions of component geometry, material and output quantity have a decisive impact on the possible applications of the machine,” explains Hartmut Stöhr, Managing Director of bending machine specialist Schwarze-Robitec (producer of machines branded Schwarze-Robitec, Robitec and Schwarze-Wirtz).
“In our case, the procedure itself complicates the sale of second-hand machines by third parties. If one of our tube bending machines has been designed for example to process thin-walled pipes in mass production, it might not be suitable for bending thick-walled high-pressure tubes for plant construction. Ultimately, whether the drive concept and machine design can produce perfect component quality under the new conditions can be judged only by one of our specialists.”
Exceptionally high risks
The fact that second-hand special-purpose machines are bought time and again without consulting the manufacturer is the result of economic considerations, as Stöhr knows: “It naturally sounds attractive if a machine from a prestigious manufacturer can be offered at an apparently very reasonable price for one’s own production.”
Consequently, however, buyers of bending machines frequently take excessive risks. Machines are therefore taken over with no prior testing. Initial testing takes place only on the new production site. Under these conditions, it is of course impossible to verify whether the system has the required capacity.
“Before buying, it should at least be ensured that the machine actually works properly. The control must show no errors, the mechanics must not be worn and the machine must be complete in terms of its components,” Schwarze-Robitec Managing Director Bert Zorn points out perhaps the simplest basic conditions. “It must then be presented in test mode, in order to be able to clarify for example that all of the axles still work properly. However, these criteria are really the absolute minimum and they are adequate in only the rarest of cases. There is generally a lot more to be considered.”
Small things can tip the balance
Time and again, the bending specialists are confronted with enquiries from users who have already bought a second-hand machine and encounter great problems a short time after the start of production. “We are contacted when the horse has bolted and the machine does not work,” Zorn says. Even small things can tip the balance here – for example if incorrect hydraulic filters are used, resulting in problems with the hydraulic pumps after a short time.
Information in the manufacturer’s database
On the other side, rogue sellers sometimes exploit the ignorance of buyers: old plants are repainted then even given false type references and accordingly sold more expensively. It is also a problem if original components have been replaced or improper repairs or alterations carried out on the machine. Customers are additionally left in the dark about possible difficulties with obtaining spares for very old parts. In the event of production problems, even the original manufacturer’s fitters are sometimes baffled, as they cannot repair the foreign parts and the result may then be expensive downgrading to original condition.
Ultimately, Schwarze-Robitec therefore recommends asking at some point before any investment decision. “There are various options if you contact us,” explains Jürgen Korte, Authorised Representative at Schwarze-Robitec. “We can look at our records to see exactly which machine is being offered. In addition to the delivery condition and the exact age of the machine, we can then also provide statements about whether the machine has undergone regular maintenance by the manufacturer. This is at least an initial indication of the current condition of the plant. Moreover, we can assess whether the machine type offered is an option at all for the application area.”
Focus on safety technology in the case of second-hand pipe bending machines
The ideal way when buying second-hand machines is therefore to buy from the original manufacturer. As well as factory-tested second-hand machines, Schwarze-Robitec also supplies reconditioned machines. In the case of the bending specialist, reconditioned means that the manufacturer restores the machine to mint condition by complete dismantling and reconstruction from scratch – naturally including the latest control, electrical installation, hydraulics etc.
Furthermore, the reconditioned system is also always compliant with the current safety regulations and therefore has CE marking. This is a very important topic, particularly when buying a second-hand machine. If machines display no CE marking and their safety technology is incomplete, they must not be placed in operation. In some cases, even the lack of operating instructions – with directions on the correct procedure in case of damage – might be enough for a second-hand machine to not comply with the safety regulations. “For an original manufacturer, such things naturally go without saying. The customer also receives a full guarantee on our reconditioned machines,” Authorised Representative Korte explains the advantages of buying from the manufacturer.
If there are no spares
The issue of spares is of similar importance when buying a second-hand machine. Here, of course, the older the machine, the less reliable our stock. Generally, only the machine manufacturer is able to say whether it is still possible to obtain vital components in case of damage. Here again, the database provides information on the components used in a machine. However, from this perspective, a reconditioned machine is always the first choice. In this case, all obsolete components are replaced – from the control to the smallest sealing ring. Moreover, the manufacturers guarantee lasting operation of the system through an extensive service provision. The question of spares is then resolved from the outset.
Better brand new?
In which case should a second-hand machine be avoided and a completely new system chosen? In the view of the specialists, the product range and daily use of the machine are critical. “If no series parts are to be produced and enough time is scheduled for maintenance and repair, a second-hand machine is certainly an option that can be considered,” Managing Director Bert Zorn states.
“However, if production is dependent on a high level of availability of the plant and you want to benefit from the advantages of the latest control generation then the company is better advised to have a new machine or a reconditioned plant. A new machine can then also be completely customised to the requirements of the customer. We recommend that any company interested in a pipe or tube bending machine or wanting to pass on their old machine first contact us, the manufacturer.”
Checklist for buying second-hand pipe and tube bending machines
Resolve these questions before buying a second-hand pipe/tube bending machine:
- Is the machine suitable for the required component specification? (Ask the manufacturer.)
- Can the machine achieve the output demanded at maximum load? (Ask the manufacturer.)
- Is the rating plate in place and does it match the machine?
- Are complete operating instructions pertaining to the machine present, including all maintenance documentation and wiring diagrams? In which language are the instructions?
- When was the machine last used?
- Does the machine control show errors in test mode?
- Does the mechanical system seem stable in test mode (no play, disturbing noises or similar)?
- Are all the current safety regulations (CE marking) completely fulfilled?
- Can all spares be obtained easily? (Ask the manufacturer.)
- Have no structural alterations been made to the machine?
(Main image: Machine in dubious condition.)
Company Contact:Bert Zorn
Press Contact: Rebecca Brisbois - additiv pr GmbH & Co. KG
Edited from various sources by Elizabeth Corner
Read the article online at: https://www.hydrocarbonengineering.com/special-reports/26072013/guide_to_buying_a_second_hand_pipe_bending_machine/