quote:Originally posted by britishtrident
You must like ugly.
The TF was one of the best looking production cars ever
Shoulda gone to Specsavers, BT: I'm with choc-ice, here - the TD and TF are the fugly ones, and were generally criticized as such in-period due
to the nose-heavy look created by the radiator in front of the axle line. In terms of 'vintage' aesthetics, that's just the biggest
bungle you can make! The smaller wheels don't help, either. The TC was much prettier, I reckon!
In terms of the JC Midge, one thing it might be useful for is the construction technique: IIRC, it the main tub was made of decent thickness plywood,
but faced with very thin aluminium. Relatively heavy, perhaps, but it gives you the advantage of a much simpler timber sructure than the old
ash framing techniques, and the thin aluminium (supported by the ply) is supposed to be very very easy to form.
The Midge is interesting, I don't need the full size plans for £99 but a paper copy will probably show enough detail for a tenner, thank you.
Looking at photos of the Midge they look quite slab sided, think it's possible to curve the sides in at the bottom and from the seats to the
scuttle? I'm sure my idea of thin sheet plastic would curve but I don't know about the Midge's thick plywood.
As for being told I like ugly, if it's anything like girls they're usually more fun
Interesting plan about welding plastic sheets, you might not be the last to use that technique.
You can bend it with a heat gun too, so that offers potential for the scuttle. CAD should be able to generate some template so you can check the shape
during bending.
I've made some progress but it's been so incredibly slow that even if it was a month since the last post, you'd say I was a
slacker.
Since my last post I've gathered some parts from real TCs to give it a head start in terms of shape and proportion. Someone suggested earlier
that I use a metal TC scuttle with its complex double-hump shape instead of worrying about how to make it myself so I did this for some other parts
too. Here's what I've found after looooong searches:
Fibreglass front wings - £100
Fibreglass rear wings - £75
Metal scuttle - £100
Fibreglass front apron - £30
Original radiator shell - £150
All these came off TCs that were bodged through the 1960s and 70s when they were cheap old cars and were now being properly restored. It might seem
like a lot of expensive parts but metal front wings are £2200 a pair, rear wings are £1700 and the scuttle is £500, my costs are a lot less than a
"real" one. A radiator shell? £1200!
I couldn't progress on the chassis with anything more than the rough idea I had before, unless I had a 1970s Midget to measure up the suspension
components for. I kept an eye on eBay, Facebook and anywhere else I could think of for a Midget that was rusty but had its suspension parts. Even a
set of complete front suspension parts is £300 because people use them on their Austin A35s. This was a bit pricey for my project which was
definitely still in the planning stage.
After a while, this came up. Someone had used the parts they need, intended to use the shell for a hillclimb racer but changed their mind and now
just wanted rid of it. Isn't it beautiful?
ok, it's not beautiful, but the price was free as long as it was removed before that weekend. Obviously the car was 100 miles away but
that's what Shipley is for, so for a price of about £130 it was picked up and delivered to my house. This meant I could measure up the
suspension units at my leisure and then design the chassis.
I went along to the kit car show at Stonleigh and had a look at some ladder chassis to get an idea of the size of box section I need. The real TC
uses a channel section rather than box section, but it's about 75mm tall. After looking at several chassis from Reliant, through Cobra (both
using 75mm tall box section which must make the Cobra a laugh with all that torque) and finally Marlin (the strongest of all at 100mm box section?) I
settled on 75mm x 50mm box section with 3mm wall thickness.
I positioned them in the CAD over this drawing to get things in the right place
And this is it
Which allowed me to sketch in a ladder chassis picking up on the suspension points (mostly)
Back to the bodyshell, here's something that I didn't bank on - getting the shape right. I had factory drawings, I had a basic CAD model,
I had a 1:24 model kit, they'd all overlay and be the same, right? I couldn't be more wrong!
I bought a book by Mike Sherrell called TCs Forever which is basically the restoration bible. It had loads of information about size and shape of the
body tub which didn't match the factory drawings.
But that's ok, because the factory drawing of the bodyshell didn't match itself between the side view and the plan view!
Neither of them matched up with the CAD model I had, but that's not too surprising because getting the shape absolutely correct is proving to be
very difficult. In the end I went for the TC's Forever drawing with just a hint of the factory drawing, because back then the
"master" was what was being made in the factory, not what the drawing office thought was being made. As for drawing complex curves and
tying up different views? There were about a million places that could go wrong and just one place it could go right.
I used the drawings to produce these curves in the CAD, which describe the curve of the bodyshell front to back, and how it curves under lower down
the body tub. Then we'll fast forward over the checking, rechecking, putting it into the main assembly and checking again... The straight
lines in blue are the major width and length dimensions that I was reasonably sure of, it also allowed me to transpose the parts from one assembly to
another for checking.
From these curves I created (yeah right, the CAD created) the complex curve of the side of the tub
I'd spoken to a metal fabricator about chassis and he'd told me about laser cutting of tubes. It's no problem to mark and cut the
chassis tubes myself, but he said if you want real accuracy on a chassis, like 0.1mm per cut, use something like this. It's hypnotic to
watch.
This is the only way to cut intersecting round tubes without driving yourself crazy but because the machinery works so fast, it can be cost effective
for square tubes too. It also gave me an idea of how to finally do the body shape that I needed instead of that tricky and expensive mucking around
with shaving wood to shape.
I used the surface to assemble box section metal to, then to describe the way I needed it cut. Like this
I've spun the view around a bit so we're looking at the left side of the tub but from inside. There's a sill that gives the lower
shape, a vertical (in one plane) post that's the door hinge at the back and then two longer pieces which are the door striker and the front of
the body tub.
With the surface removed, the body assembly looks like this
It gives me plenty of weld area to the 50x75x3mm box section at the bottom and locates the 3 uprights I need with good accuracy. I can now add an
upright which will give me the top seat belt anchor and horizontal pieces to run along the top of the rear wheelarch.
I'm still undecided on the bodyshell itself, I could use plywood, plastic or even sheet metal to do the tub.
I spent a while with a complete 1500 Midget and took some basic dimensions of the engine. If I use the engine, gearbox, suspension and steering as is
planned here, I'll have no problem getting enough points to keep an age related plate.
As you can see, there's still an awful lot to do, but at least it's moving forwards a bit. Comments and help are welcome!
About 20 years ago my dad restored a TC. He was missing the front wings. By sheer change he was chatting to an 'old boy' in the pub one
night who used to work in the factory hand making wings. He offered to make some for him - my dad turned up the next day to this random tatty shed,
not expecting much, and found him just finishing the second one on the wheeling machine(for 150/pair). When asked how he measured the bits (since no
plans or drawings were in evidence), he was told it was just by memory/eye. We fitted them when he got home and they fitted as well as anything else
+-1/2" difference in the length/width of the body panels from one side of the car to the other seemed to be about the standard fit for anything!
and goes zoom)
