Printing spare parts yourself – that is one of the most frequently mentioned applications of 3D printing. However, there are surprisingly few cases in which this application is actually implemented. One of these rare cases is at the lifting platform hire company SCHMID Hebebühnenverleih, based in Haimhausen near Munich. The company uses an x400 from German RepRap to print spare parts for its lifting platforms, but also to adapt them to the demanding requirements of the rental business.
The specialist company for professional access technology was founded in 1984 and rents out high quality and easy to operate lifting platforms. Customers of SCHMID Hebebühnenverleih Minikranverleih GmbH are located in the Munich, Augsburg, Landsberg area and also in the entire Allgäu region. The equipment available consists of all types of work platforms. These range from trailer-mounted lifts and compact 3.5 ton truck platforms, truck-mounted equipment, scissor lifts, telescopic boom lifts and articulating boom lifts, right through to special machines, such as versatile and maneuverable track aerial platforms with an extreme narrow transport width or telescopic scissor lifts with a load capacity of up to 1,000 kilograms. SCHMID has recently also started offering mini cranes. Besides standard solutions, the company also develops individual solutions.
SCHMID Hebebühnen offers a full-range selection for all conceivable operating conditions up to a working height of 45 meters. If additional height is needed, SCHMID can also offer platforms with a working height of over 100 meters via the nation-wide PARTNERLIFT network. Mini cranes with heights up to 21 meters, suction cups for handling glass and special equipment for tree cutting and stump cutting complete the range on offer.
The rental business presents one of the toughest operating conditions for any machine, since machine wear is high and operating errors are unavoidable due to the renter's usual lack ofexperience with the particular device. CEO Mario Schmid explains: “Our lifting platforms are subject daily to tough operating conditions, in which plastic covers are often damaged due to careless operation or falling objects. As these lifting platforms come from relatively small suppliers and are produced in small numbers, the spare covers are disproportionately expensive and delivery times long. The 3D printer enables us to produce the covers more easily and as required.”
A second important area in which 3D printed covers are used is the adaption of the devices to therental business, Schmid continues: “The control consoles are often unnecessarily complicated and provide access to functions that the normal customer never requires. If users nevertheless press one of these buttons, the vehicle often breaks down and the customer has to phone us to obtain help. This previously made up sometimes 10 percent of our daily calls. Customers are then also dissatisfied because they cannot continue working until the problem is fixed. With a particular machine type in the fleet, 90 percent of the hotline calls were caused by these kinds of operating errors.
SCHMID Hebebühnen solves this problem by making special covers which block the unnecessary functions and only make the important displays and operating elements accessible. These covers were previously made from sheet metal by hand and with considerable effort.
Mario Schmid bought himself a small 3D printer for private use and soon recognized the potential of this technology, particularly for the applications described. An analysis of the 3D printers available on the market ultimately led to German RepRap and their x400 model. Schmid recalls: “The frameconstruction and the finishing of the RepRap printers gave the best impression of all the products available on the market. We were also interested in a large build envelope in order to be able to also manufacture large objects. We were also very pleased with the flexibility in relation to material selection. The demonstration of a printer and the process from the concept to the finished project ultimately impressed us with its efficiency and versatility.” The x400 has been in operation since July 2016 and has made itself indispensable.
SCHMID Hebebühnen primarily uses PLA as the print material because there is virtually no distortion during printing and virtually every print is successful. Materials such as ABS have a low thermal stability and are not used in typical applications at SCHMID. Schmid's experiences with PLA printingon the German RepRap x400 are very positive: “In designs subject to mechanical load and printed in PLA, the wall thicknesses have to be somewhat over designed in all cases. The infill should be set to around 30 percent, so that the part is robust enough for use on our devices. Corners that have to be in contact with the build platform should ideally be rounded in order to prevent the workpiece from detaching.”
There are now many new application areas for 3D printed parts, Schmid now creates on the x400 blind covers for the dashboard of his trucks, which are often lost or broken. The new covers are more robust and retain the clean look of the dashboard.
Lastly, the specialists at SCHMID are replacing the plug connectors of operating elements to machines with a fixed connection to ensure secure and undisturbed connection. For this a part is modeled and 3D printed, which is used simultaneously as a cable feed-through, strain relief and cover for the hole in which the connector is fitted. Screwing and gluing produces a water tight butslightly elastic connection. Schmid adds: “Previously we used a metal sheet with a cable gland, butthese are not elastic and tend to be torn out.”
“The x400 gives us a number of benefits,” Schmid adds. “We save a lot of money by using our own 3D printed plastic parts instead of the very often expensive spares of manufacturers, which are difficult to obtain. Customers are also relieved and have to pay less for repairs. The manufacturing of sheet metal covers with which we cover operating elements and simplify operation previously required considerable time – the lead times have been reduced and the x400 prints the new covers automatically and often overnight. The 3D-printed parts are more precise and have a better appearance, which increases the value of our machines. This ultimately means our hotline is contacted less often for actually avoidable operating malfunctions and downtimes are reduced for the customer. Looked at more closely, the 3D-printed parts and thus also the German RepRap x400 have a strategic value for the company – the machines are easier to operate, the customers are more satisfied and we save time and money.”