I’ve done more CAD drawings – but this time I’ve started to build it.
Whilst surfing I spotted a cool sketch of a 1937 Ford Slantback Sedan. It turns out a small production run of them were made.
This Hot Rod isn’t a true replica but a modern interpretation of the shape.
The next job was to sketch up what the body would look like shrunken (considerably) over my Haynes Roadster Kit Car chassis. The drawing below is very crude, but served a purpose.
I’m not the first person to shrink a Hot Rod body over a Haynes Roadster chassis, there is currently a black ‘n’ flamed Austin 7 Sedan doing the circuits and I also remember a white Ford model Y coupe from years back.
Both of those had long bonnets, that from some angles just look odd, so I kept the passenger compartment in proportion with the original. The problem with doing this is that the driver seat is actually a fair way back from the windscreen. I therefore decided to check the IVA manual (Section 32 – Forward vision) for the construction rules. Luckily, I even had room to move the seat further back or indeed the screen forward. However, if I moved the seats upwards just 1.5 inches then the line marked ‘C’ would be exactly half way up the screen.
The annoying part was, a while back, I had bought some Saab seats and upon getting them into the workshop the first thing I did was cut off the seat adjusters and lower the seats. I then threw away the unwanted seat frames. Shame I now needed them and the original height would have been perfect.
At Beaulieu Auto Jumble I bought a MG Midget screen and frame in perfect nick for £25. You can get new screens with the correct E43R markings (IVA manual Section 45) for less than £45 but this one will do for mocking up. The MG screen was ideally 1 inch too tall for a true scale model, but I raised the roof to accommodate this. I could have set it into a slot in the cowl or had the screen chopped by a local guy, but this just seemed smart to save myself the hassle. The CAD model still has a very chopped and sectioned look so nobody would know useless the too Hot Rods met side by side.
The next problem was the steering column, with the seat shifted up higher, my legs no longer fitted underneath. This meant cutting out the whole framework holding up my Corsa power steering column and welding in a completely different arrangement. I wish the knock on effect stopped there but sitting higher made the pedal angle slightly funny. Not hugely, but enough for me to get hacksaw the out. The new pedals; to the untrained eye; look exactly the same, but I’m much happier.
If I had scaled down the wheels the rims on the back, they would have been 17″ and the ones on the front 13″. (I think the original Hot rod ones were 22″ & 19″). I plan on using big brakes and have already set up all the suspension for 19″ wheels. To make my 19″‘s work, I put taller arches into the CAD model. This helped in giving the car a more sectioned look.
The keen eyed of you out there will spot that the headlamps on the orange Hot Rod are off a face-lifted BMW Mini Cooper. I got my pair from an early pre-face lifted BMW Mini One, as they look far less modern, have more traditional glass markings and white indicators lenses. These headlmaps are less teardrop shaped than the original 1937 items but I’m sold on the Mini items as good modern replacements.
I haven’t quite finished the CAD and I haven’t worked out the door issue, but those things can wait under I get the wire frame welded up.
In the image at the top of the screen you can see that I have modelled the above shape using a grid pattern or wire-frame. The intention is to make a skeletal mould out of 5mm bar that exactly follows the same lines as the CAD wireframe. Over the wire-frame I will then use the English wheel I am making to form the body. From previous blogs, you will see that I am also making various other pieces of metal working equipment including Shrinker/Stretchers, Guillotines, Sheet Metal Brakes etc. I have been watching 100’s of hours of tutorial videos and the plan is to spend a long time making the bodywork. I guess that I will make many of the panels several times before I am happy. Luckily for me and unlucky for him, the Brother in Law is a utter Guru in Sheet metal fabrication. See here: http://www.metalmeet.com/forum/showthread.php?t=10681 – So I might badger him for the odd tip too.
What is interesting when CAD modelling, is that if you get a point on a line just 0.5mm out then it looks like the car has been in a shunt, exactly the same as it would if it was real. Therefore perfecting the model is going to be a little tricky. I’m hoping that by using long lengths of 5mm & 8mm bar to make the frame, it will have a natural amount of spring tension to it, that will help me correct any minor inconsistencies in the model.
I will be building a large overhead gantry that travels on runners around the car. Mounted on this gantry will be a combination of rulers and 40mw cross hair lasers. A minimum of 2 lasers will shine down onto the car. In conjunction with a large height gauge, I should be able to target a point in 3D to a fraction of a millimetre. It will also be possible to match one side of the car exactly to the other.