Monday 9 July 2018
There you are, lying sleepless in bed with a head full of ideas that you know will excite your client: carved 3-dimensional shapes that will bounce the light and shadow the voids. As day breaks reality comes crashing in. The hours and hours spent making the piece will either bust the customer's budget or bankrupt the workshop, so it's back to the CAD screen for something a tad more conventional.
But it doesn't have to be that way thanks to Computer Numerical Controlled (CNC) routers. Originally developed for mass manufacturers to carry out repetitive jobs with absolute precision, ease and cleanliness, doing the jobs of panel saw and spindle moulder, and with the ability to cut mortice & tenon joints, the CNC router frees the maker of fine furniture from design constriction.
For the price of a luxury car Barnaby Scott of Waywood took the plunge and bought one just over a year ago. He wanted to take advantage of its 3D and 2D cutting abilities. “One particularly exciting aspect is its 3D shaping capability, so that when we start designing we can start to let our imaginations run free. Inevitably when designing something you have to keep half an eye out for how you are going to make a piece, so have to get back to the real world because of budget. I've always hated that, but the more capable the kit the less you have to make those compromises,” he said.
“A perfect example is a 3D shape that I would otherwise have had to hand carve, and where one 3D shape interacts with another. That's a major headache and hugely time consuming.”
He said that table legs resembling ribbons could be cut viably on the CNC router, adding that he had just made a cabinet where the handles appeared to bulge out of the doors.
“It had a beautiful curved inner surface in a different wood. The two handles came together at the corner of the cabinet as if mitred together.” The mitre and the void left a beautiful 3D shape, work that would have been so difficult and so slow by hand that they would never have done it.
That was a £12,000 commission and Barnaby reckoned that without the CNC machine the true price would have been nearer £30,000, therefore unviable.
“The other side of the machine is its 2D capabilities which really do speed up cutting shapes. We still use templates but where we used to have to draw out and cut a template and transfer it to a jig which would then be mounted on the spindle moulder – very long-winded – now we draw it on the computer, put a piece of wood on the machine and it will cut out a nice sweeping curve. All of that stuff was economically viable before but it is so much easier and accurate now. The saving in making time is not ridiculously dramatic but it is the repeatability and now we don't have to store templates. All you are storing is a programme on a computer with a minimal number of jigs and templates.”
He said that the machine was used for most of their work in some way though for many pieces its input was small. Take the cabinet we are working on now. It is still very hands on. We're just about to make an oval table. In the past we would have had to get out old pieces of string for the trammel method but now the machine just makes a perfect ellipse.
“People talk about erosion of skills but that's an absolute nonsense. We're still embedded in the craftsman way of working, with one person seeing the job through to the end. It's another tool in our toolbox. We've had the machine fully functional for a year and most of that time has been spent on making jobs that were in the pipeline. We are now beginning to break free but there will always be constraints. Before we had a spindle moulder we had to design that way, now we design in the knowledge that we don't have a 5-axis machine, but the gloves are off. It has been exciting.”
Waywood will be using the machine to cut a jigsaw-pattern oak floor for the showroom.
Gareth Neal and Matthew Burt also exploit the advantages that CNC use brings to their work. Gareth even mounts a saw blade onto the machinery to create his skeletal pieces. Last year he told F&C: “I've always wanted to use the CNC machines to do something.
“There are so many exciting opportunities with different processes going on. The world has opened up the design/art furniture, and it's a huge industry with lots of amazing objects out there.”
Matthew, who is known for his evangelical approach to wood as a resource to be treated as a precious material, has no problem with the use of CNC machines and variously either buys time on them to cut 3D repeated shapes or hand carves where the job could have been done by CNC. He makes a tray from offcuts that is CNC-ed apart from preparation, assembly and finish.
“We use tools from biblical to digital, and will chew it with our teeth if necessary to bring it into the world,” he said of his workshop's making processes. “We are very fortunate to be alive and have the full spectrum of tools to help,” he said, adding that it was necessary to keep checks and balances on how they were used.
â€œComputers can dominate and destroy. Any tool is only as good as its operator, only as good as its cutter maintenance and only as good as the designer behind it. It's a question of if the tool can bring work to the hand more quickly it is very useful. If it can do more work more economically it is very useful but I don't want it to dominate what I do.
“It's a very large investment that normally ends up benefiting the banker but the repayments are considerably less than what you would pay in a year to a maker. It's a very useful addition to our armoury of tools. He said that when he began working in wood the material could be manipulated by not that many tools. Now we are flooded out with tools. We need to take a measured response to which tool to use according to which idea you are bringing out. The way you use them can start to dominate a workshop and in most hand-workshops this is another task the maker needs to learn because when you get a CNC it is like another apprenticeship, so I buy time on one, but if I was bashing out more product I would invest in one.”
One company that is no stranger to the benefits of CNC routing is Unto This Last. Based in Brick Lane in London's East End, it takes advantage of the speed offered by the machine to give lead times of between one and three weeks to make items of furniture within an extensive catalogue to the finish of the customer's choice.
The core material is Latvian birch ply and the name of the business echoes the title of the book written in 1860 by John Ruskin who, in the wake of the Industrial Revolution, advocated a return to local craftsman workshops.
Ruskin also said: “A thing is worth what it can do for you, not what you choose to pay for it”.
Had he written this today would he have included the CNC router in his reckoning?
Like a printer
The easiest way to grasp how a CNC router works is to liken it to a printer, with a cutting tool instead of ink and the ability to work in three dimensions instead of two. Work is composed on a computer and then the design is sent to the machine for the hard copy. This outputs a 3D copy of the work using the machine's X, Y ands Z axes for motion control. A file is created, the workpiece is clamped down, the file is activated and the CNC machine gets on with the job.