Three Bridgeport GX 480 three-axis vertical machining centres in 2 years…
As its name suggests, Prototype Projects is in the business of fast turnaround production of low-volume and one-off components. It offers its customers a range of additive technologies, including stereolithography, fused deposition and laser sintering, as well as CNC machining.
For its CNC operations, it depends on the quality, performance and reliability of Bridgeport machines and over the past two years has installed three GX 480 three-axis vertical machining centres. These complement the first CNC machines the company bought, a Bridgeport VMC 1000, purchased in 2000, and a VMC 600 purchased in 2004.
Based at Royston in Hertfordshire, Prototype Projects serves the cluster of product design companies around Cambridge, as well as major OEMs.
Managing Director Justin Pringle explains: ‘Our clients are clever people. They are very good engineers who know the processes, they know the materials and they know what they want the part to do in the end product. They will model it in a CAD package and we produce the part using whichever technology they want.
‘Working for design consultancies, we never know what is going to come through the door next. It could be anything from a consumer product to a medical device.’
One thing that every job has in common is that the customer wants it quickly.
Justin Pringle says that a typical turnaround from CAD file to prototype on CNC machining could be three to five days, but on a rapid prototyping part then it is quite feasible that it could be delivered the same day. Lead times are very short and there are hardly any forward orders.
‘Looking at the order book, we are busy tomorrow, fairly busy the day after and then after that it is whatever comes through the door. There is literally no visibility on the order book at all.’
This makes capacity planning very difficult and demands machines that are reliably available whenever they are required.
‘We rarely say no, and we will always find a way of doing it. We have a good team of guys here; they understand the importance of turning things round quickly. The quicker we turn it round, the quicker we get to the next job.’
He says that this speed of response and versatility is crucial in this sector.
‘We’ve been in the business a long time and we know how to turn things round quickly and manage the short lead times,’ says Mr Pringle.
Moving into CNC machining and developing the skills of making parts direct from CAD data has been a key contributor to this capability.
‘We got our first CNC machining centres in 2000 when we upgraded from Bridgeport Interact semi-CNC milling machines to the Bridgeport VMC 1000. It is a very good machine, which is still running thirteen years on, and four years later we added a Bridgeport VMC 600 – which is also very good.
‘We were traditionally a model-making company, but as our skill set changed we got more into CNC machining direct from 3D CAD – taking the CAD model direct and using that rather than having a drawing and programming it on the machine.
‘Word spread that we had this capability and it fitted well with the design consultancies who were being pushed to get projects done more quickly – and as a consequence our capacity needed addressing. We survived with the two VMC machines until we added our first GX480 in 2011.’
He says that the company had always had a good relationship with Bridgeport and Regional Sales Manager Jack Carter, right back to the time of the Interact machines.
‘When we came to invest we did look at other machines, but the quality of the Bridgeport machine was just far better than any of the competitors. It was an easy decision to make with the quality of the machine and our experience with Bridgeport. We were really confident in the quality of the machines.’
The GX 480 is a robust workhorse machine with a high specification and a compact footprint. It offers a 480mm by 400mm by 430mm working envelope with axis travel speeds of 36m/min, a 10,000rpm, 7.5kW spindle with a BT 40 taper, and a 16-tool magazine.
Mr Pringle says that around the end of 2011 it was clear that further capacity was required.
‘We were seeing increased demand for all our services, and in particular for CNC machining and we noticed a marked increase in the amount of work we were subcontracting out. So, based on our experience of the first one, we decided to order two more GX480 machines.’
This time, it was not just the performance of the machines that was decisive, but also their overall size.
‘We are a compact business in terms of our footprint, so it was quite difficult for us to make the decision – not that we needed more machines but where we were going to put them. The GX 480s are very compact machines and the height in particular was a key factor. We managed to move things around to fit them in. We’ve eked out every last bit of square footage.’
He is pleased that his long relationship with Bridgeport is continuing following the creation of ETG Bridgeport earlier this year when Hardinge transferred its UK sales, service and customer support activities for Hardinge and Bridgeport machine tools to The Engineering Technology Group.
‘The transition has been seamless,’ he says. ‘We haven’t noticed any difference and we still deal with the same people we have always dealt with.’
Summing up, he says that the new machines will help to cement the company’s position in the local product design community.
‘We have some very good consultancies on our doorstep. There is a wealth of knowledge in the area, and what is key for them is to have really good local suppliers to support them. Our new investment is a direct result of that requirement.’