Installation of a new FSW facility at TWI
By: Stephan Kallee [1] (TWI)
On 7 March 2001, two TWI employees visited ESAB to inspect the progress on the SuperStir TM machine construction, and to establish the delivery and installation programme. With respect to the latter they have requested the programme of work and time scales described below. During this visit the mechanical construction only awaited the two racks for the 8 metre axis. All the electro-mechanical and computer control equipment was in place and under test. The machine construction and build quality was of a high standard that is expected from ESAB. All the improvements suggested at the last progress meeting have been taken care of by ESAB.The machine installation programme was conducted as follows:
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Fig.1. Installation of the 8m long rack-and-pinion tracks © 2001, TWI Ltd |
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Fig.2. Arrival of the ESAB SuperStir TM machine for the EuroStir ® project at TWI © 2001, TWI Ltd |
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Fig.3. Assembly of the ESAB SuperStir TM machine at TWI © 2001, TWI Ltd |
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Fig.4. TWI can now friction stir weld large components of 8x5m such as complete side panels of double-decker buses © 2001, TWI Ltd |
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Fig.5. TWI's new ESAB SuperStir TM machine which will be used in the EuroStir ® project © 2001, TWI Ltd |
- Monday 25 March to Thursday 29 March 2001 - Two TWI technicians travelled to ESAB and to attend a machine introduction course, comprising machine construction, operation and programming.
- Wednesday 28 March and Thursday 29 March 01 - Two TWI technicians and the Principal Consultant witnessed the machine buy-off trials at ESAB with TWI staff operating the machine. From a welding demonstration standpoint only linear welds were made due to the welding tools and work clamping available. Nevertheless, welds were made 6 and 12mm deep in 6082-T6 plate at speeds of 700 and 150mm/min respectively. The machine was also demonstrated, when welding, using tool position sensing or the down force control on its own.
- Monday 2 April 2001 - ESAB delivered to TWI the bedplates on which the machine rails were attached. TWI and ESAB staff positioned and fixed the bedplates to the laboratory floor by Friday 6 April ( Fig.1).
- Saturday 7 April 2001 - The EuroStir ® machine arrived at TWI and was unloaded by a heavy lift contractor ( Fig.2). The 8m rails were lifted in position on the bedplates. The other machine parts were positioned in a manner that assisted the machine construction. Two ESAB engineers commenced the machine installation.
- Sunday 8 April 2001 - The ESAB engineers with the aid of TWI staff aligned the machine rails on the bedplates. After the alignment was complete they grouted the rail to the bedplate with quick setting cement.
- Monday 9 April and Tuesday 10 April 2001 - The machine carriage and crossbeam assembly were lifted in position ( Fig.3). The carriage legs were installed and located with a tie bar.
- Wednesday 11 April and Thursday 12 April 2001 - All the machine services were connected and the machine was tested in manual mode. The ESAB engineers returned to Sweden during the afternoon of the 12 April.
- Tuesday 17 April to Friday 20 April 2001 - The workstation base plates were installed between the machine rails.
- Monday 23 April to Friday 27 April 2001 - The ESAB engineers came again to TWI to adjust the SuperStir TM machine for automatic mode operation and to test the instrumentation ( Fig.4). They undertook staff training (operation and maintenance).
- Monday 30 April 2001 - The availability of the machine for EuroStir ® research, was demonstrated after obtaining the necessary clamping equipment.
The machine needed a CE marking which was the joint responsibility of ESAB and TWI. ESAB took care of the machine as supplied, but TWI was responsible for the necessary CE risk assessment, for the protection of the operators and any visitors. Because of the large working envelope of the welding heads separate operator and visitor safety zones were necessary. Operator safety is no problem, provided TWI adheres to some basic rules, which were prepared and will be policed. To provide sound visitor safety the machine required railings on two sides. For visitors to view the welding operation a TV monitor in parallel with the operator's TV monitor was installed.
The effective x-axis travel distance is currently 7.85m. This is because an E-stop position has been necessary to give the operator protection from being struck by the gantry. If necessary, the distance of 8m that was specified can be achieved, but changes to the E-stop will be required.
The machine roller that can be brought into play, just ahead of the welding tool, to hold down the workpieces, has independent pressure control and therefore reacts against the tool down force. Consequently, when working in tool down force mode the roller force has to be subtracted from the tool down force to obtain the true down force.
Because the design of floor plates has been changed, the distance between the floor and the tool is now 1,430mm (not 1,500mm). However, this distance is when the tool is at its lowest position, which means in the raised position the distance to the floor is actually 1,730mm ( Fig.5).
With respect to work handling equipment, TWI staff have found and acquired some workstation bedplates and suitable T slotted tables, which have been purchased. It is planned to develop some vacuum clamps to fit the worktables and to review some commercially available vacuum equipment.
Acknowledgement
The author wants to thank his colleagues for assembling the SuperStir TM machine at TWI. He is especially thankful for the contribution of the following technicians who worked overtime during two weekends:- Stefan Björk (ESAB)
- Rui de Frias (TWI)
- Nathan Horrex (TWI)
- David Staines (TWI)
- Sören Stafstrom (ESAB)
Links and references
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Project Manager of EuroStir
® is Stephan Kallee (TWI),
stephan.kallee@twi.co.uk