When you’re unsure, redraw.

Sketch by Jon Tremlett for soulcraftcandy 2014

Ok, so there’s been a bit of a gap between this and the last post, I’ve been working, putting in some serious time on a freelance job, one which involved constructing a couple of full sized mock ups of some new airline seat concepts, in polyboard. For those of you who don’t know, polyboard is that stuff that folk normally use for presentations, a couple of sheets of very thin card with a foam core. It’s great for what it was designed for but, it also makes a great modelling material provided you know what you’re doing. I’ve been making models out of this stuff for longer than I care to remember so it presents few challenges as such, the main obstacle these days is that the forms that are created in CAD by the designers are so complex that we are now operating well beyond what a basic sheet material can achieve.

Polyboard_model1

Fortunately there are ways around this, including software that essentially creates complex nets for making paper models, which can be utilised to assist in turning curved surfaces into flat plates that one can cut, bend and glue together. It’s hard work, but becoming a skill fewer and fewer people possess, so there may be hope for me yet! Here’s a pic of the kind of thing I’ve been building. This is a very old model so no one will mind me showing it, the more recent stuff is, as usual, highly confidential so no pics of that for a few months at least.

Anyway, enough about work. Todays post is actually about this sketch above, the next stage in creating the drawings for Mr. C. After my initial efforts, see the relevant post here, it became obvious that what I wanted wasn’t anywhere near what I’d initially drawn so was beyond a quick set of modifications. Only one thing for it, redraw the whole thing. Not a problem, the learning and critique of the first sketches really informs your hand second time around so the process is more focused and as a result much better. What I do find though is that I can’t force this part of the process, it has to happen when the mood takes rather than when sitting down and telling oneself to get on with it. Needless to say the use of the magic blue biro helps as well, laying gentle lines first and slowly building up. This is now much more what I’m after in terms of view angle, the position of the bike on the page, the curve of the road and where the police car is. This will now get transferred onto Bristol board for the final bit and I’m already thinking I should do another version in tandem which shows a motorcycle which is closer to the kind of bike Mr.C constructs using four cylinder engines. More very soon, and thanks for taking the time to read the post today.

Creative decisions that are right for you.

Taking my time to find the right position.

Taking my time to find the right position.

Time to take a look at cutting and fitting the new rear mudguard. There is much talk in bike building circles about getting the stance of your bike right as a prerequisite for coming up with anything good looking. There is a school of thought that is very prevalent currently to have the line of the bike very flat. That’s to say, the visual line from the back of the seat running through the base of the tank to the front suspension should be pretty much parallel to the ground. Hence you see lots of bikes that are all starting to look the same and share the almost totally flat seat which is almost ubiquitous in its manifestation. This is all well and good if you’ve got the time, money and the need to go down this route. Personally I haven’t. As I’ve mentioned before, without resorting to large amounts of frame modification  (read expensive welding bills and jiggery) and spending a whole pile of cash on different suspension equipment, there’s not much one can do beyond a certain point. The creative challenge is therefore to move away from the standard look enough to create difference and come up with something that works with the proportions one is presented with. This can be a lot harder than you think, but it is possible on a very limited budget and is generally a case of taking ones time in positioning, cutting and mounting components. Once you’ve cut metal there’s very little you can do to rescue things, so it pays to exercise patience and adopt a methodical approach no matter how quickly you want the project to be completed.

Position set, holes drilled, just the light to mount.

Position set, holes drilled, just the light to mount.

Of course, what “looks right” is a purely subjective conclusion. Because these kinds of projects are pretty personal in their nature, the result must first be right for you, in your own eyes. That’s the most important thing really. Decisions you make in a build are always contextualised by a whole host of factors and compromises that one has had to deal with on the journey to the final outcome. Others may not like your final iteration but then invariably they have little knowledge of this context. As a maker, of anything, one has the luxury of knowing that you could change or modify things in future if the urge takes you, but it’s an option that you can reserve to exercise if you so choose.

When I first built this bike I made a pile of decisions about how it would look based how I felt about the life it would lead, about practical issues like comfort and durability as much as aesthetic considerations. I reserved the right to change things if I wanted to but generally didn’t feel the need to do much other than periodic tweaking. Now, some time later, it is time to make some changes  based on living with it and riding it for a few years. There are still certain things about the stance I can do little about, but these are not a problem. The bike started life as a factory custom and so caries with it some small legacies of that life which I’m happy to live with, like the long forks and the steep rake of the tank.

A rather blurry shot courtesy of my iPad, but you get the idea.

A rather blurry shot courtesy of my iPad, but you get the idea.

So here are some shots showing the process of getting the new rear mudguard (fender) sitting in the right place, at the right angle in the right way. Once I’d cut the bare rolled section I’d bought to roughly the correct length I spent ages with bits of foam, tape and cups of tea trying it in different positions to get the look I was after. Once I was happy I marked the mounting holes for drilling and returned to the shed for some hole making. The critical factor was getting enough section over the wheel without it looking overly long but still having enough curve available to support the light/plate assembly at the right angle. I didn’t think things had changed much until I held up the new piece next to the old one to see that I’d actually reduced the length by about 150mm, very satisfying.

The final shot shows the guard in place with the light mounted and everything else ready to go. The final piece of this refresh is painting the petrol tank, which I’m currently working on a design for and I’ll be posting about that very soon.

Advice and opinion, don’t confuse the two.

Instruments: before, big and busy. After, uncluttered and simple.

Instruments: before, big and busy. After, uncluttered and simple.

There is a big difference between advice and opinion. One serves to guide and promote discourse, and the other invariably confuses things and promotes argument. I learned the difference between the two a long time ago and am constantly reminded of that lesson. When seeking advice we are generally hoping to tap into the accumulated knowledge and experience of others whose judgement we trust. Opinion on the other hand is generally something that follows acting upon advice and is subjective, unless of course, the other person has misconstrued your original query, in which case you get a whole load of one when you wanted the other. When I’m engaged in making stuff I ask for advice, when I need it, from other makers I know, and I might canvas their opinion when I’ve finished what I’m doing, but not before.

New headlight brackets and new front indicator light mounts.

New headlight brackets and new front indicator light mounts.

If I’d followed all of the unsolicited “advice” I’d been given about how my bike should be, then I would have wasted a great deal of money and time on what is essentially a cheap form of transport. Working within an admittedly self imposed tight budget, and with time pressure to match, the solutions that interest me are those which are simple, relatively easy to execute and fit for purpose. It is with this in mind that I approach everything I do on this build and it helps to steer things clear of needless expense and wasted effort. One day I might build something more special but, for now I’ll work with what I’ve got. Sorting out the instrument area and the headlight would have been “better” if I’d totally stripped the bike of all electrics, cable drives and other bits, but that doesn’t clear the deck, it just opens up a whole new avenue of expensive solutions to a new set of problems. Working with what’s there meant splitting the clocks to allow cable drives to flex more freely and shorter light mounts to keep things close in and fairly tidy. The bundle of wiring needed to keep things working would stay, although shortened and repackaged. I’d bought some ‘P’ clips some time ago thinking they’d do for mounting the light on the forks and so put them to use. they work well enough for now though I may make replacements with a tighter fit later on. I drew up some side brackets on some graph paper (brilliant for laying out simple parts to scale) and transferred the design onto some aluminium alloy for cutting out. I made a new speedo mount based on what had been there before, but with a 20 degree offset and modified the mounting that came with the tachometer when I bought it, to bring it closer to the handlebar. All this allowed me to raise the light and split the clocks, and try to keep things as low as possible. By tilting the bars back further I was getting near to where I wanted the front to be. It looks a lot more sparse than before, but I’ll get used to it. And the natty little fly screen has gone.

I was very fond of it, but it had to go. A quick word about making those side brackets. Because I’d drawn them out on graph paper, it was easy to draw them again on alloy sheet, you remember all the numbers. I cut them out using a jigsaw, slowly, with a blade for metals at slow speed. I finished them off with hand files and drilled the holes with a hand drill. It takes time but not as long as you’d think and the result is pretty tidy once they’ve had a rub down with 600 grade wet and dry paper.

Here’s a canny bit of advice given to me by my father just before I started this: when filing soft metals, rub chalk along your files, it stops them from clogging. He was right, it did too. You can’t beat good advice. His opinion? Well, he didn’t have one, he’s waiting until I’ve finished to give me that.

Seize the moment.

Stripped and ready for action.

Stripped and ready for action.

The decision to get cracking on the bike coincided with two pieces of good fortune. First, work called just before I started on it to ask if I’d mind staying at home that week as there wasn’t enough work going through the studio to keep me busy. Regret that I wouldn’t earn any money that week was countered by the prospect of getting a fair crack of the whip on my bike build, so a reasonable result. Then, to my utter surprise, the weather turned unseasonably warm and sunny for about a week, perfect for fettling bits of metal out in the shed and garden. Having wrestled the bike into the back garden, no easy task given a very narrow access alley out back and the need to fit some much reduced width handlebars, the strip down was quick. Originally I’d built it in a way that would enable me to take it apart if I ever needed to and so was grateful for having made that decision. The work plan was front mudguard first, then the clocks and headlight area and finally the rear mudguard. After a quick once over and a clean it was time to get started.

Not bad, considering.

Not bad, considering.

I’d sketched out several solutions for mounting the front guard but, in the end opted for the simplest one which used two straps or hoops connecting the mounting holes on the fork legs with the guard mounted on top. Ok, not that elegant, but essentially all you need and adhering nicely to one of my general philosophies when approaching making anything, which is the KISS principal (Keep It Simple, Stupid). Due to the front forks having a leading axle arrangement, the mounting holes are off-set to the wheel centre so the straps needed to be of different lengths, and so I slotted the holes on the rear one to enable some positional adjustment when finally mounting the guard. Trimming the guard from the longer piece of rolled section I had was relatively easy, the tricky bit is joining it all together. For this you need to find the centreline of the guard, awkward on a thing that curves in two planes. My simple solution was to lie the piece on its side and establish the centreline as a height rather than a width, using a pen taped to an adjustable square. That done, it’s much easier to define the hole positions for your fixing screws or rivets to attach the mounting straps. Nothing worse than drilling holes only to find they’re in the wrong place. With the holes drilled I screwed the whole thing together using some M4 button headed screws and thread lock compound. Doing it this way allowed me to tighten things up just so, and minimise the risk of pulling the surface down onto the straps too much and dishing the top surface. The rolled mudguard blanks came with a polished finish but this is a nightmare to maintain, so the final thing was “brushed” with Scotchbrite before a treatment of anti-corrosion spray. Ok so far. Next up, the clocks and front light area.

Creative imbalance and making the most of what you’ve got.

Small, but with lots of potential.

Small, but with lots of potential.

It is the only word I’ve managed to come up with in trying to describe what’s been going on of late, imbalance. I’ve got a fair idea about where it’s come from and it has taken me a while to get to grips with it.

Rather than castigate myself for allowing it to happen, it has been much easier to recognise it for what it is and deal with it through action and a little reasoning. This imbalance stems from a shift in my working life over the last few months, and hence my creative output, which I’d not accounted for. Although my role is only part time, it has involved a lot of idea generation and thus a massive amount of drawing and sketching. Big projects, which require a lot of this kind of thing in their early stages, need sustained creative input and masses of ideas. It’s exhausting, creatively and physically. Where I went wrong is not remembering this to be the case and failing to keep any creative energy in reserve for my own stuff once I returned home. So it’s been difficult to draw, but more to the point, it’s been hard to generate ideas.

Shed_2

I’m showing you a couple of pictures of my garden shed, here in my back yard, as it has proved to be the answer to coping with this imbalance. Rather than spend any more time staring at blank sheets of paper the solution lay in getting out there and making something, turning raw materials into something else, using some tools and getting my hands dirty.

 

There had been a plan in the back of my mind for a while to refresh the little 250cc motorcycle that I’d modified some years ago when I started this blog. Over the years, as the miles have racked up, it has suffered the usual knocks and scrapes that these things are victim to, and overall the finish was starting to look very tired. I wanted to give it a freshen up, and make some changes to the overall design that I’d not got right first time around. So what to do for a making project was all ready and waiting, I just had to start. Before now I have relied on using workshop space owned by other people, this time around I didn’t have that option so my little shed was going to need to be the work space that I could use. As you can see it’s a small building with very limited floor area, but it does have an electricity supply, a big light on the rafters  and a work bench across one end. It houses all of my various tools, materials and other useful stuff accumulated over years of working as a prototype builder and modelmaker. Being of a sturdy design and construction it allows all manner of things to be hung from the walls, freeing up floor area and permitting at least a modicum of organisation. I don’t own any large machine tools, I’d need a bigger shed if I did, so most of the work would be done with hand and power tools with my trusty old Black and Decker Workmate acting as a secondary work bench. The only thing I can’t, and likely won’t do in there is spray paint, that will have to happen elsewhere. The shed was here in the garden when we moved into the house and I’ve always wanted to use it as a making space. now was my chance to put that thought into practice.

It just about fits in.

It just about fits in.

The third shot shows the bike pretty much in the shed. I didn’t need it completely inside, just enough to get some soldering done on the electrical loom, but it meant that I could work on it in there if the weather took a turn for the worse. By being methodical and tidying up as I went it was utterly surprising what I managed to do in this small space. Most of us work in some kind of organised chaos. Some cope well the more chaotic things are, others less, and over the years my natural inclination has veered toward the organised rather than the chaotic and this is a boon when working in a confined space. Having everything to hand helps too but, the order one maintains around oneself really is reflected in how one deals mentally with the making process.

The fruits of my labours are in the next post.

 

The 3D Pantograph Club, Part 2: Jon’s Machine.

3D Pantograph built by Jon Tremlett.

The Pantograph, finished and installed.

In the previous post you will have read my story about a 3D scaling pantograph built by my sculptor friend Ed. As I also mentioned, my and Ed’s friendship started after we realising we shared a passion for motorcycles and an interest in these rather esoteric sounding pantograph things. So in this post I’ll shed some light on how it all came about.

The 3D pantograph, pictured above and covered in this post is a machine I built for a young artist a few years ago after being recommended for the work by another modelmaker. It is in some ways quite different to the one built by Ed, though in others it shares many similarities. There are no given set formats for these machines and so each is a direct response to a brief from the person who’s going to employ it. In my case the machine was to be wall mounted and capable of achieving quite a high level of accuracy, with variable scaling ability anywhere from 2:1 to 4:1. The artist sculpted in clay so no cutting actions needed, purely surface finding. As a consequence, this variability and need for precision dictated many of the design and fabrication decisions taken during construction, not forgetting the ever present need to work within a tight budget.

Cheverton Pantograph at soulcraftcandy.

The Cheverton pantograph used for reproducing scaled sculptures in alabaster.

To be honest I had never heard of a 3D pantograph when the job first landed in front of me, but all became clear as I took to the internet and arranged to go and visit one, currently residing in the archival warehouse of the Science Museum here in London. This particular machine was known as the Cheverton pantograph, named after the victorian industrialist who designed it for the manufacture of carved alabaster busts from scale models. It is a beautiful machine, quite a bit smaller than I imagined and a great example of a style of engineering design, lots of architectural references, so loved by the victorians. I freely admit that this machine heavily influenced my design, though it must be said that aside from some mentions of odd machines in America and Italy there is very little out there for the budding pantograph builder to study in order to construct their own. The Cheverton machine showed very clearly the pivoting arm for scaling pointer mounting, the different length pointers for achieving correct scaling and most important of all, a compact system for creating the two rotating turntables that enable the sculptor to access all points around a form.

3D pantograph by Jon Tremlett

The first iteration in the studio showing basic scaling function.

The image above shows the very first iteration of the machine temporarily installed in the artists studio. You can gather roughly how it works from the position of the two pointers relative to the positions of the two eagle sculptures positioned on the boxes. This was very much a prove out exercise, to make sure we were on the right track and to confirm some aspects of the geometry whilst I was building the rotating table structures. Because there was little or no documentation covering the detailed design of these things, it was quite a challenge to work out the exact geometry which governs how the machine works, and thus achieve the level of accuracy demanded by the artist. We encountered many problems to start with but overcame them once we’d realised what was going on. The essential premise is this: Firstly, the exact centre of the ball joint at the root of the moving boom needs to be on exacly the same line as the centres of the two scaling pivot joints. These three positions must be aligned by a straight line in space. Secondly, another straight line must pass through this ball joint and the two tips of the pivoting pointers. And finally, this latter line must also pass through two points at the centres of the tops of both of the rotating turntables. Simple enough you’d think, but a devil to work out without prior knowledge.

3D pantograph components by Jon Tremlett

The main pivoting components made using machined scaffolding parts and a lot of aluminium.

The scaling function of the machine is achieved through the relative positions of the pointer pivots along the main boom. For example, if the scale required is 3:1, then the second pivot would be three times further from the ball joint than the first. So if the first is say 500mm from the ball, then the second would be 1500mm from the ball joint. The pointers are also of different lengths in accordance with the selected ratio and correspondingly, the relative positions of the turntable centres needs to adhere to these spacings too. This means that for a machine like this, where an infinite degree of variability was requested (anything between 2:1 and 5:1), everything needed to be adjustable and lockable. Hence the pivots slide along the boom, the pointers slide through the pivot blocks, the turntables slide along their guide rails and finally, the chain drive that connects the turntables, which must turn in unison, expands or contracts in order to maintain chain tension across varying distances.

Rather than plough on endlessly, I’ll leave you today with some captioned photographs of the build which I hope will serve to fill in some of the background. Sadly I don’t have any more recent pictures, the machine was moved when the artist changed the location of his studio and I haven’t managed to gain access yet. I will keep trying though.

3D pantograph detail by Jon Tremlett.

Detail shot of the short first pointer locating small turntable centre.

 

3D pantograph detail by Jon Tremlett at soulcraftcandy.

Turntables, rails and chain drive under construction.

3D pantograph details by Jon Tremlett at soulcraftcandy.
Detail of the chain drive using proprietary bicycle components.

3D pantograph details by Jon Tremlett at soulcraftcandy.
The complete turntable and chain drive assembly ready to be installed.

 

 

The 3D Pantograph Club, Part 1- Ed’s Machine.

Ed Barton Pantograph on Soulcraftcandy.

Ed and his 3D Scaling Pantograph.

It is an inescapable truth of freelance working for creative companies that you are rarely in a position to show or talk about the work you are engaged in, or have just completed. Issues of client confidentiality, and the fact that much of the work is usually a long way from entering the public domain mean you can’t show anyone what you’ve been making for quite a long time after the event. Hence the lack of “making” content on the blog for a long while.

Prompted by a recent visit to the studio of a sculptor friend, this is about to change however, as it has nudged me into digging a project out of the archive in readiness to post about it.

I first met Ed up at the Ace Cafe, a favoured north London haunt of motorcyclists, where I got talking to him about his fabulous Moto Guzzi. When we discovered what each of us did for a living, and dug a little deeper, it became clear we had more in common that purely an appreciation of personally customised motorbikes. Ed mentioned that he was interested in building a 3D Pantograph, and I had completed the construction of such a device not that long previously. Needless to say he was interested in understanding what my project had revealed regarding these rather esoteric bits of equipment and a good many knowledge sharing conversations ensued.

Before going any further though, it is probably best to try explain what a 3D pantograph is exactly. I will try and be brief. A pantograph is essentially a scaling machine that allows the operator to enlarge, and in some cases reduce, the size of an image or object. They are more commonly found in the 2-dimensional realm where they are used to trace lettering or pictures for engraving and such like. Being utterly analogue in their function they have now been generally superseded in most applications by digital technology, so they are rare things to come across. Working from a fixed pivot point, two pointers, connected by a series of pivoting arms allow the operator to follow an image with one pointer whilst the other creates a replica of that image on another surface at a greater scale, like 2:1 say. In 3 dimensions the principle is the same though in this case the first pointer follows the surface of an object, positioned on a turntable, while the second allows the operator to create a scaled up or reduced version of that point in space on a second turntable nearby. If this doesn’t make sense, then I hope that seeing some images and a short film will help to make things clearer.

The pantograph pivot and counterweight assembly.

The pantograph pivot and counterweight assembly.

Last weeks visit to Ed’s studio in Camberwell, South London was to finally see the pantograph he had built. It was impressive. Through our earlier discussions we had figured out that these machines could take many forms, it is the core geometry which provides the link between different designs. So not surprisingly Ed’s machine is a very different looking beast to the one I built, and amply demonstrates how a different “brief”, ie what you want to make with it,  effects the final design and layout of the machine. Here’s a link to the studio website where you will find a great stop frame film of the guys building their machine and then using it to cut complex forms out of large blocks of expanded polystyrene with a hot wire, and other images. When I visited the studio last week the hot wire had been replaced by a high speed cutting head which the guys had used to carve even more complex forms from similar blocks. You will also see that the machine consists of the two main elements required for the pantograph to work, a pivoting arm that holds the “pointers” and a pair of connected turntables supporting the final piece and the model from which it is being traced.

Ed Barton pantograph at Soulcraftcandy

The business end, a high speed cutting head.

In the next post I’ll reveal the details of the machine I put together for an artist, and expand a bit more on how these things work.