I stumbled on some amazing videos of advanced machine tool centers at the European Machine Tool show in 2011. These machining centers were demonstrating some very high performance software called hyperMill developed by Daishin Seiki of Japan. The company’s website is in Japanese, but you will find some high profile video on YouTube, and it is extremely impressive.
The advanced software allows a single machine tool to do coordinated motion between a 4 axis milling head and a 2 rotary axis work holding base. By using this type of coordination, a long cutting tool can cut inside pockets within a 3 dimensional part that would be otherwise inaccessible. What is even more impressive is the large tool magazine that includes engraving tools that allow the machine tool to generate extremely precise surface finishes without moving the part to a different machine for processing.
This kind of capability comes with a high price tag and is generally reserved for aircraft and advanced one-of-a-kind scientific projects. Machining material like titanium, for example, requires extremely high stiffness in order to hold the extraordinary tolerances that the control system is capable of.
For more examples of the extraordinary capability of these machines, check out the guitar building video on the Daishin Seiki YouTube channel.
What is really interesting is thinking about the cost of the helmet manufactured by this process. If the machine costs $750,000 to buy, on the basis of a 2000 hour production year operating a single 8 hour shift, the hourly rate for the machine is $375. If the machine runs at fully capacity for 6000 hours its only $125./hour.
Typical cost for the machine grade T7 series 264 pound block of aluminum is probably in the range of $1500 to $2000. The final part only weighs 8 pounds, so there is a lot of waste.
The process takes just under three hours, which is pretty quick considering the amount of work being done.
Cost of housing and maintaining the equipment and other considerations aside, the helmet is a work of art at $3000. not including programming time. Programming time in the most fluid 3D CAD environment would be huge. Maybe you could get a design service to do it for $50K.
But what if you wanted to make the helmets at the full capacity of the machine? Probably best to start with a rough casting at 10 pounds, or about $10. worth of material at the commodity rate of a castable aluminum alloy. You’ll need a mold and foundry, so that will cost some money. If the machine could be run on the basis of a full 8000 hour production year, and it produced a helmet every hour (assuming the reduction in machining since there is no rough shaping from a block), then you would have about 8000 helmets at a rough cost of $135. each.
At a selling prices of $275. each, 8000 helmets would be worth $2.2 million dollars. That would easily pay for the machine in one year with plenty of money to pay for a worker to tend the machine, load and unload the machine, and people in the shop to keep the machinery running. It would pay for the rent and electricity and cost of marketing the helmet as work of art (not as an actual helmet). If the machine is paid for and you sell another 8000 helmets, the entire revenue stream is profit minus the labor and operating expense.
That’s called capitalism. And there’s room for more.