Going spare
Paul learns ‘lathing’ for the world’s least practical classic
There are few things more satisfying than starting out with some bits of steel and ending up with a part for your car. There are also few things more time-consuming than amateur metal fabrication – measure twice, cut once, trial-fit, realise you still didn’t get it right, measure again, cut again, weld it back together, trial fit again, throw in scrap bin in fit of rage, start again with the measuring – but for me that makes it even more rewarding when a job turns out well. If you get to learn new skills along the way, all the better. Much of my Lotus was hand-made back in the Fifties, so reproducing missing parts can be done the same way.
One of the first bits of fabrication I tackled was the throttle crossbar that is a feature of the first Sevens. A simple tube mounted in an eyelet at either end, it provides a pivot for the pedal and enables arms for cables or rods to be welded to it, providing a suitable throttle linkage for whichever engine option you are using. I had been able to measure one on a car belonging to Lotus Seven Registrar John Watson so I had a good idea of how it was made. By using two diameters of tube, the long inner section could turn easily in the eyelets that have a small hole drilled for oiling. If I wanted to avoid a lifetime of filing, four sections of the larger tube would need parting off, which would mean access to a lathe. For me lathe access means making a cup of tea for Mike Maingot – a fabrication and engine-building genius who occasionally shares our workshop – or buttering up my friend Seth by telling him how well his Morris Oxford restoration is coming along. I used up two favours this time, with Mike cutting the tube, and Seth taking the rod away and machining my welds smooth. I can’t finish the throttle linkage until I have the engine in but I already had my eyes on a trickier job.
Like many modern Caterhams and historic racing Sevens, my Lotus was missing the spare wheel rack that should protrude from the rear of the chassis. Unlike Caterhams and racers, mine wasn’t missing by design, but because it had rusted through at some point and fallen off, leaving two thin fragments of tube sticking out from the aluminium skin of the body. There was
‘I was childishly excited at getting my hands on a lathe for the first time’
a lot of head-scratching as I worked out how to affect a repair with enough strength without damaging the aluminium skin. I didn’t want to leave the rack off as I plan long trips in this car and I would be sure to get a flat if I didn’t have a spare. I know my luck…
This is not a drill
I decided to drill right through the rear tube and make some stubs from steel bar that I could slide the rack over, giving me something more substantial to weld to than the rusty remains. I have found ebay to be very useful for buying small pieces of steel stock, so I bought a 17mm bar, the same size as the internal diameter of the ¾in tube I was using for the rack. The stubs that would pass through the rear of the chassis needed to be turned down to 10mm to slide into the holes I’d drilled. Mike wasn’t about, perhaps wise to what the sound of the kettle means, but Seth suggested I could come around to his shed and try my hand at making the stubs myself.
In all my years of messing about with old cars I had never done any machining so I was childishly excited at getting my hands on a lathe. Sensibly, Seth turned one stub and I copied him. Mine wasn’t quite as neat as his, but I was pleased with my first results of ‘lathing’ as I insisted on calling it, much to Seth’s annoyance. As hoped, once closely fitted through the chassis tube these stubs gave enough strength to support the spare wheel even before they were welded in. Next I borrowed a tube bender from Mike to make the rack. The radius wasn’t as tight as would be ideal but close enough that I could live with it. After bending and welding on the rack, I made two uprights and a tab to attach a numberplate and light to. Looking at period photographs, the first Sevens made do without this light, but it appears to be an MOT requirement now and was easy enough to fit – the light is an original Lucas L534 picked up at an autojumble. At this point I realised that if I’d been really clever I’d have drilled through the length of one of the stubs to pass a wire through, but it was too late now so I could only route the wire through a portion of the tube – still, it is neat enough. The rack was brush-painted with Technogrip, supplied by Colorite in West London, who were able to mix the paint to match the greeny-grey of the early Lotus chassis from an original brake drum I have.
So, I now not only have somewhere to put my spare wheel, but a reminder every time I look at it of the brilliant friends who helped me make it and the skills – tube bending and turning – that I learned along the way. What could be more satisfying than that?