What playful mechanical invention can we do? Water irrigation systems? Cable car transport? Emma Bearman from Playful Leeds asks? What can we…
I bumped into Nick at one of the superposition meetings, Nick Roberts is a bio mechanics engineer working with a method called finite element analysis, (By making a detailed systematic analysis of the all of the elements in a structure you have the method of how to build one – see reverse engineering.) In Nick’s case its applied to the the human body, his current area is working on the stability of bone structures being attacked by aggressive cancer called multiple myeloma. In his spare time he works with making different mechanisms eventually turning these into sculptural forms such as 3ft animated puppets.
Interview is here in a rough cut audio for,
Where does meaning lie for you with machines?
It has to do a job. Its a tool. So a tool has meaning in that it is specifically made to do a particular thing, a particular purpose. Whatever that purpose is, that’s its meaning. So essentially its a doing thing it has to do something otherwise there’s no machine.
Do you think there’s almost been a loss of understanding in meaning of machines through everything being in these little black boxes as you described it yesterday.
Yes, its an increasing thing especially from an industrial point of view for things to be in black boxes. Its really simple for users, its just press and go that’s the usability thing. But also from a strictly manufacturing point of view and a sales point of view you also get a concentration of expertise in the company. So all the people outside the company don’t really know how to use it. You get more revenue because the black box is sealed unless you’re the person who made the black box so there’s also been a massive drive in that direction.
But the manufacturing techniques are such that now you’ve got this concept that’s really broken through massively in the last 10 years and its called system on chip. Before you had say, a circuit board you would have different components and if one of those components broke you could run a diagnostic and just change that component. Its not so simple now because all those components have now been shrunk onto one chip so if that component breaks on that chip you have to replace the whole chip and they’re usually so integrated with the circuit board and everything it means you have to change the board. So the idea of technicians is even becoming more abstracted from the actual design of what’s going on. So technicians now will change the board they won’t change the component because the component’s integral into something really, really complicated.
So this idea of black box is getting more and more abstracted from the fixability. From an engineering point of view the fixability is becoming more abstracted.
I have a friend who’s come over from Bugundy. He was amazed by how people fix cars over here. People take them to the garage here and he just couldn’t understand that because where he’s from, everybody fixes their own cars. He asked me if he could use my welder, this is what started it. I said, ‘oh yes, I can come over and do the welding’, he said, ‘oh no I can do it myself’ and I said ‘oh most people don’t you know’ and then we got into this whole conversation about being able to fix your own car and that really triggered my thinking about this black box mentally because now its harder to fix your own car because a lot of it is done electronically. Things that would have been done mechanically are now done electronically. Like the timing on the engine block used to be done via a chain but now its done solid state where the timing is done via sensors. So that’s a shift away from a mechanical thing that once you saw it, you understood how it worked. Now you’ve just got these little black boxes with bits of rubber encasing around them and you’re not really sure what they do.
When I was speaking to Alan Kemp, the Inventor, he was saying every thing is so reliant on GPS now that we’re only 5 days away from certain doom. He was concerned that the big container ships were being controlled by GPS, and that they weren’t paying for proper sailors any more, that they were hiring cheap labourers who knew how to operate GPS. It seems like the more we evolve with this technology the cheaper it gets and the smaller it gets the more disconnected we become.
We become more reliant on it. Personally, I’m in to evolution through technology. No surprise being an engineer; but if its applied correctly it can solve all our problems. That thing with the GPS cargo is a scary thought. If these things go down, its all over.
I think now with where phones are, there’s not necessarily any one person who necessarily knows how to fix everything down at that level
and it makes them more throw away. Just the littlest thing can go wrong on one of the systems and then that’s the whole board gone. Its not economically viable to fix them its cheaper to just get another one off the production line and just replace it. They very rarely actually fix things.
With the whole mechanical side of things you can actually see what’s happening. The machine has more meaning in a way because you can understand how it works.
You can visualise the inner workings a lot easier. You don’t necessarily have to be technically proficient to understand how a bike chain works, you can see it, its pretty obvious how it works. For me, I think there are a lot more mechanical solutions to problems than there are electronic ones
Especially with undergraduates when they think of this amazing thing and the first thing they say when they explain it; ‘it’ll be controlled by an Arduino’ oh really? What everything will be? You’re going to pile it with all these electric motors and your going to control it all from one central place and they’ve absolutely no thought to the mechanics of it. Its all going to be done electronically. Straight off the bat. And yet there some of these beautifully elegant mechanisms that are there in these source books that go back to Victorian times that would solve that problem beautifully and you wouldn’t have to be debugging your Arduino because its not doing what you thought it was going to do and you’ve sent that byte the wrong way round and its now going backwards. Even in a highly technical atmosphere like this, students don’t think to go down the mechanical route first their first thought is; oh, we’ll get a computer to control it.
I can understand it, but for me that’s not where the fascination is. Whereas the fun in it is actually try and make that happen in a mechanical way. How can you make a mechanism re-create that movement. So yes I’m very interested in the idea of direct mechanical without conversion from one energy form to another.
What kind of struck me when you were talking before when you said about looking at a bike chain you can instantly see how it works, means you can instantly see how its broken.
One of the things I try and instil in people is the mechanical principles involved. So there, very basic leverage is possibly the most important mechanical thing you’ll ever learn ever and the applications of it are just phenomenal. I think on that score there are mechanical principles that if people were told straight off the bat that these things work this way then its up to them to scale it up.
Mechanical advantage in different gears of a bicycle. Typical forces applied to the bicycle pedal and to the ground are shown, as are corresponding distances moved by the pedal and rotated by the wheel. Note that even in low gear the MA of a bicycle is less than 1.
I wonder if there are a key set of these mechanical principles that would be easy to understand and given to people in a visual comic book form. Would they then actually think ‘I need to move this from there to there and I know that this lifts so much so I can scale up’. A visual lego of what to put together..
Basically learning the alphabet of mechanics. From my side any way. Mechanisms and the strengths of the materials used to make those mechanisms. The actual simple idea of how the mechanism works and then what’s the supporting structure around it that allows it to carry the loads that it does.
The history of mechanisms, even at graduate level is a missing component which at some point can save people a lot of time, a lot of trial and error. A lot of these solutions have been done and done very well and efficiently before and yet you get these people trying to re-invent the wheel.
If you just have a basic understanding of maybe 12 mechanisms that can do pretty much any mechanical job and there you have your ABC down and then its how you apply it and link it together to form sentences and purposes.
There’s something really exciting about the idea of the little parts of knowledge that we know and are almost getting forgotten here that’s something that’s worth sharing with places that don’t necessarily have education but have the impetus to learn through doing.
A lot of these mechanisms can be made really simply, from real simple stuff, but its just knowing that concept exists in the first place and then going out and playing with it and see how to make it from whatever materials you’ve got.
So it’s more like a problem solving handbook who knows what problems they’ve got that are meaningful to them. Going back to this idea of direct drive. Maybe start with this idea of gym and gym energy. So we’ve got all this excess energy and rather than it being turned into electrical energy and it going back into the grid which is only 70% efficient, you use 100% of the direct drive energy. Alan Kemp in London suggested you’ve got this universal spinning device that’s coming out of the ground opposite the gym, a universal coupling for anyone to use. With this circular motion, what potentially could you do? What objects could you explore?
The prime mover is the basis of almost all Victorian engineering. So the idea that there’s this big fly wheel and you connect to the fly wheel and then that powers anything. Literally anything. All the electric in here is done from a massive prime mover at Drax power station. Its just some massive spinning thing that’s generating all of this.
Can you explain how a fly wheel works?
You know the idea of momentum, so something has momentum. You can translate that into circular motion so things can have angular momentum.
So once its spinning, it wants to carry on spinning, a gyroscope for instance it wants to carry on spinning it doesn’t want to shoot off in any particular direction, it wants to carry on going around and around and around. So the idea is that you just keep plying this thing with energy to keep it spinning and it stores the energy in the spin.
You can also use it for smoothing out the input. So say you’ve got this really intermittent, spiky input it’ll get smoothed out with the angular momentum of the fly wheel. Washing machines is a classic example. You’ve got the weight of all the wet material. That wet material is going around which is causing a pull that way one minute and a pull that way, a pull that way so you get this wobbling thing. In the back, you’ll see that there’s a massive spinning weight as well and that’s a fly wheel and if you take that out your washing machine just pulls itself apart. So the fly wheel is actually dampening the load transfer and spreading it out.
So a washing machine would be a good thing to re-purpose.
The great thing with washing machines is that they have the controller with them. You have this massive electric motor where you’ve got the electric controller board there that you can basically send whatever commands you want. Also, from a sheerly mechanical point of view, even if you’re not using the motor you’ve got all your belts, drums and things like that already housed so you don’t have to build a mounting for it or anything, it’s already done. Then you can just pull off whatever output that you want from it.
So for me its giving people the ideas of what you can do with that circular motion. The kind of things that have been done before like turning that circular motion into reciprocating motion. Just linear translations of a device. That in itself is just such a simple basic thing that you’d be surprised at the amount of people who ask how to do it, yet its a fundamental mechanical principle that’s been known forever.
Machine demonstrating conversion of rotary motion to reciprocating motion using gears. The bottom pair of gears drives the mechanism.
So things like that, that linkage from the pedal and the rotary motion and just giving the ideas about how that motion can be changed into useful meaningful work. The idea of conveyor belts even, circular motion to other circular motion and what that circular motion can do without converting it to linear motion and then turning it to linear motion and the different kinds of linear motion you can get from circular motion.
So its basic elemental link between what your output is and what your input is. You have the input, you’ve got the circular motion. What exactly is it you want to turn that into? For me that’s all about mechanisms and understanding a certain basic set of mechanisms. Then you can play around with it. You can swop and change the mechanisms however you want to get whatever output you’re after.
Is there a list of those that could be…
yes, there are basic mechanisms that fall into certain categories and they’re based on a certain principle. There’s gearing and different types of gearing, linkages and different types of linkages and then there’s things like clutches and brakes. Poly systems, intermittent mechanisms. Geneva wheel on old projectors. The frame is always; dwell, move, dwell, move. But that can all be done from a Prime mover that’s constantly spinning. So there are these simple ideas that have been done. There are solutions to particular problems. The problem is immaterial. The solution is there and it can be re-purposed and put into other settings
And then the scale of that could be, the more bikes you’ve got, the bigger the wheel could be, so it could be a small scale or a large scale, so scale is out of the window to some degree.
To some degree yes, but that very much depends on your purpose. Why are you making the machine? What’s the machine for? Then that dictates the scale and everything. But the underlying mechanical principles are pretty much the same regardless of scale
What playful mechanical invention can we do? Water irrigation systems? Cable car transport? Emma Bearman from Playful Leeds asks? What can we…