Optimization… In general, most plants want to mix up the cutting list, while still controlling the order that the members cut by the saw. This allows some gains in waste/cost to be had by combining members but still allows the cut components to be stacked easily according to truss once they come out of the saw. Interestingly, over the past few years I have seen a number of plants starting to re-think this approach. Some plants are starting to say forget about the order of the components coming out of the saw – let’s give the saw full rein and let it come up with the very best solution possible! The approach might sound half-baked at first, but there are some compelling justifications behind the strategy.
First, if we look at the more traditional approach, plants tend to mix and match components but more or less want the components to come out truss by truss. In most cases, our customers will let the system optimize, and hence cut, a few trusses at a time to reduce waste and/or cost, but they are essentially controlling the order in which the members come out of the saw. This means that stacking the cut components on trolleys is relatively straight forward, but the restrictions placed on the optimization to maintain the order naturally prevents the best possible solution from being realized. It also means that the order of the raw timber being fed into the saw will tend to be random. The argument for this approach is that it’s much easier to load timber onto the infeed in a random order than it is to stack cut components by truss on trolleys when they are coming out of a saw fast and in a random order. Fair enough!
But the flip side of this is that timber cost is a substantial portion of the total cost of the truss – significantly outweighing labor costs, or so I’m told. If a random (or at the very least a highly relaxed) order of cut components could be handled with little, if any, additional labor costs, then why not – but how? Well, one approach is to stack the components based on member type – not truss. Taking this further, a truss build order number might be printed on each member – i.e., which trusses are to be built first, second, third, etc. In this case, the operator simply stacks all like members in a certain location (for example, on a tree-trolley) and in the order specified by the build number.
Another approach I’ve seen is to use additional outfeed kickoffs to help sort the members coming out – certain trusses and/or member types go to certain kickoff locations. This might not seem like a viable option for most plants, but there are many different ways of achieving a multi-kickoff system without necessarily taking up more space. As an added advantage, once you give up trying to sort out the outfeed side of the saw, you can instill order on the infeed without sacrificing waste/cost – cutting all sticks of timber that are of the same grade and length at once for example. This makes loading the infeed even easier – which, of course, means a savings in labour.
Which method is right for you – I can’t answer that, but there are enough plants thinking outside the box with this one that I thought a brief discussion might be warranted. There are usually compromises involved in most optimizing approaches, but, with a little creative thinking, almost anything is possible!
Ed Serrano is a Director of Vekta USA. Born in Florida, he moved to Australia to study Mechatronic Engineering at Curtin University. Ed graduated in 2004 with Honours and then started working for PFP Technologies with the Razer Linear Saw. In 2009, Ed purchased the IP and rights to the Razer saw and formed Vekta Automation with his wife and brother. Ed has over 14 years experience with industrial automation projects specifically for the timber Truss and Frame industry. With a solid understanding of the conditions and needs of truss plants and his experience in industrial automation, he has helped many plants improve their production and business through automation. Ed’s success in combining his abilities as an Engineer and a Business Director was officially recognised when he was named the 2018 Winner for the Medium Business Category – 40under40 in the Business News Awards. However, if asked what he’s most proud of, Ed would always say his family! Two beautiful little girls, a cheeky son, and an amazing wife are what really makes Ed tick! His family is the only thing that takes a higher priority in his life.