You’ve just ordered your pattern equipment, and you think you know how much it’s going to cost. But the cost of your pattern equipment isn’t just the amount you’ll pay your patternmaker.
This article will detail the 4 main hidden costs when it comes to pattern equipment.
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If you’re a production foundry, you probably have your own CAD-equipped drawing office, producing pattern equipment designs and layouts on any number of CAD systems.
This stage is critical. Get the design wrong, and the pattern equipment will never fully provide the return on investment needed.
How many castings does your pattern equipment need to produce? Fitting as many impressions as possible into a moulding box probably does make sense for high volume production (but not if being too ambitious causes ongoing compaction problems, or mould collapse due to inadequate contact between mould halves).
But if the volumes are low, and the series run is unknown, then a twenty-impression tool may not make sense compared to a ten impression half-size pattern.
You know that the design of the running system is critical to yield and casting integrity. Getting this wrong could be disastrous. Simulation software like ProCAST takes some of the guesswork out of this key stage.
ProCAST means that patterns with integral running systems are now common. Machining the entire pattern from one solid billet means there’s no need for loose, easy-to-change (but more expensive to buy) running systems anymore.
And what about venting? Totally necessary for optimum tooling performance, and often overlooked or ill-considered.
It doesn’t cost much for your patternmaker to ‘over vent’ when making your pattern equipment (unless loose inserts specifically for venting are required) and you can always block off any vents that are surplus. It makes the sampling process so much easier.
So, be sure to include your venting requirements at the tooling design stage. Having to add vents after the pattern equipment has been made is another hidden cost, both in terms of time and money, that can easily be avoided.
If your casting geometry is complex, and needs multiple cores, and consideration of volume production just isn’t important yet, then you may not need a pattern at all. Sintering of sand moulds (patternless mould production) may well be a better solution for you.
Obvious, but critical. Get the specification of your pattern equipment wrong, and you’ll soon be paying the price and regretting your initial choice.
For example, there is probably little point in specifying a pattern for hand mould if you need to produce any more than twenty-or-so castings. Your pattern will last, but hand moulding is labour intensive and costly.
The money you save on pattern costs will soon be spent on making the casting. And if you break the single (perhaps fragile) pattern you have, then you’ll be buying a replacement and putting an unnecessary dent in your patternshop budget.
And specifying tooling board for low volume casting production on a production plant isn’t always the most appropriate choice. It’s great for prototyping (you can glue more on if areas need to be built up, and it’s easy to machine) and cheaper than aluminium by around 15-20%.
However, as soon as you start adding reinforcing features (steel wear strips/lifting eyes) and moulding aids (brass inserts for tight pockets), the pattern costs creep up, and you probably would have been better going for aluminium in the first place.
When it comes to production tooling, playing it safe and going for cast iron when the volumes are only, for instance, 10,000 per annum is a mistake. Yes, the pattern equipment will last but, ideally (and unrealistically), you only want your pattern to last as long as the series run, plus enough life for top ups/spares. You’ll have spent far more money than needed on your pattern (and had to wait longer for your patternmaker to produce it in the first place), and you’ll never be able to get that wasted money back.
Incomplete or Inadequate Information
You know what you want, and you know where you want to buy it from.
But if you haven’t provided your patternmaker with complete or accurate information, then you run the risk of the pattern equipment you thought you were buying not being what you actually receive.
And you’ll spend a lot of valuable time sorting out queries and providing further guidance during the patternmaking process, when all you really want to do is place the order and get your pattern equipment, exactly to specification, however many weeks later.
Examples of information inadequacies could include:
Incomplete pattern layouts. Running system drawings may not contain enough detail, meaning that the pattern cannot be fully designed or made without further information (or guessing).
Conflicting views. If two (or more) elements of the layout are contradictory, there is a risk that the patternmaker will pick the wrong view to work to, and the resultant pattern equipment will be ‘wrong’. An independent review of the layout prior to issue to the patternmaker is always a good idea.
Excess information. Give the patternmaker all the information they need, and no more than that. It is not unheard of for CAD models sent to patternmakers to include superseded variants, and for the pattern to be made to the wrong revision level. Control the provision of information, and errors like these (and their costs, of course) will be avoided.
Patternmakers licence is a well-known phrase. It means the patternmaker has had to fill in any gaps in the provided information with their best guess, which is absolutely fine if they guess right.
But if they make the wrong choice, and their solution isn’t what you would have picked, then your tooling performance could be compromised. Putting it right is unlikely to be cheap, either.
In this age of CADCAM and remote communication, it’s easy for the patternmaker to submit their work in progress to you at the CAD stage. Take the time to review their submissions properly: fully evaluate the proposals and feedback, and provide your thoughts for the patternmaker to then incorporate into their work. That way, any problems caused by inadequate information can be overcome.
Race to the bottom
Cost is such an important consideration, and everyone wants the best value they can get. But going for the cheapest option can lead to further costs that may not have been apparent when you first placed your purchase order with your chosen patternmaker.
UK patternmakers will all bear similar production costs: similar labour costs; similar CNC machine & tooling costs; similar material costs; and so on.
If they are the cheapest, particularly by a large margin, then you can be fairly confident that they’ll be looking to keep their own costs rock bottom too. And if they want to make any profit, they’ll only be able to do this by minimising the time they take making your pattern equipment.
It may be that they are hyper efficient and super productive – their processes so refined and cutting edge that it takes them far less time than the competition to produce pattern equipment. But, if this isn’t the case, then the only way to reduce time is to skip stages of production deemed non-essential, or limit time spent on the essential stages of manufacture.
The stages that will be ‘missed’ probably start with quality control. Independent checks of CAD modelling work prior to manufacture will be foregone; in process checks throughout production will be sacrificed; dimensional inspection of the finished produced may well be limited; and pre-delivery review routines will be absent.
And if the costs are cut by focussing on rushed production, then trouble awaits. The CAD modelling may be rushed, which could lead to clearance/ fit errors only evident when the pattern equipment is used for the first time.
One of the easiest ways to reduce pattern manufacture time is not to finish it adequately post CNC-machining. A pattern doesn’t have to be polished to a mirror finish, but those areas that pose the greatest risk to a pattern stripping cleanly (tight pockets) may not receive the hand finishing attention they need prior to tooling despatch.
So what does all of this mean? In essence, the risk that your pattern equipment will be not be ‘right’ is increased.
It could be dimensionally inaccurate, it may be missing required features, it may not actually fit on your machines - it may just not work. All of which means that sampling time and costs are wasted.
You’ll have to spend time returning the pattern equipment and explaining your issues. You’ll have to go through the whole sampling process time again. Precious time taken to actually produce castings for your customer (the whole point of the exercise) will be lost. All hidden costs that make what you thought would be the cheapest option actually, ultimately, the most expensive.
So how can you ensure that your pattern equipment purchase is fully transparent, and that you’re not incurring any surprise costs along the way? Try referencing this checklist:
Design the pattern equipment to achieve the required casting volume, and include all the features you need (e.g. venting).
Make sure that your pattern specification ticks the boxes for your needs.
Provide your patternmaker with all the information you think they need. Ask them if they need anything else and, if they do, provide it as fully and promptly as you can.
Think about value for money rather than just lowest cost. Perhaps you’ll pay more for your pattern at the start, but the benefits from avoiding the cheapest option will mean that, as far as value for money is concerned, you’ve absolutely made the right choice.
Overall, getting your specification right first time, providing your patternmaker with the correct information to work from, as well as considering the value of your patternmaking equipment, will stand you in good stead to get the most out of your finished product.
Learn more about how you can save both time and money sourcing foundry patterns with our free guide, Buying Foundry Tooling Better.
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