Tuesday 4 August 2015

1/25 'Mad Max' Willy's Hot Rod - Part 5

Modifying the original Revell chassis for the new wheels
As usual, this 'straight forward job' has turned out not to be straight forward at all. Why do I continually underestimate what a job entails? Lack of experience I suppose...

I was hoping that the larger wheels I had found would fit onto the existing body and chassis with a minimal amount of modification. I just wanted to enlarge the body's wheel arches to allow for the chunkier tyres, but that was wishful thinking on my part. What I was trying to avoid was a 'monster truck' scenario where the suspension was jacked up and the body raised above the axels.

This is where I left off...I test fitted the chassis - as is - to the body. It was at this
point it became obvious that there just wasn't enough clearance between the new
wheels and the body. So I had to rethink how I was going to do this model.

I have worked out something of a compromise where I raised the car's body only a little, but enough to provide enough clearance between the wheels and the wheel arches to look reasonably feasible (if not entirely realistic). To do this I would have to add some blocks between the body and the chassis and also chop the length of the chassis to reduce the wheel-base slightly (because the wheels are larger).

Cut and shutOk, shortening the chassis first - as this will change the location of where the chassis attaches to the new raising blocks. I estimated that I needed to shorten the chassis by only about 3mm...


In effect this would allow me to reposition the axels closer together to recenter the new wheels within the enlarged wheel arches (moving the front axel back and the back axel forward slightly).


Having done the cut, it's time to do the shut. I strengthened the join with some brass rod then glued the two halves of the chassis back together...


You'll see from the above photo how much higher the chassis is sitting above the body of the car now (when upside-down like this). Also if you look at the front you can see how much I have moved the chassis/front axel back. I now have to think about how I will attach the chassis to the body of the car...

The green box shows the front attachment point, that's OK where it is. The red
Is the cut'n'shut where I removed 3mm of chassis. And finally the blue indicates
where I will have to move the rear attachment point forward about 4mm.

Once the chassis is glued back together properly I have to make some proper support posts to join the body and chassis together. The body will now sit 6.5mm above the chassis, now I'm not a car mechanic - in fact I don't even drive - so my 'engineering' will probably be far from realistic. I'm just going to make some plastic 'stilts' on which the body will sit on...

Yeah...Not very sophisticated, but it works. I've stuck eight of these little posts
to the chassis which raises the car body up 6.5mm.

Having got the car body siting on the chassis properly I now have to turn my attention to how the V8 engine will fit onto the chassis. Essentially its the same problem as above - I will have to make 'spacers' or 'risers' to compensate for the extra space created by raising the body over the chassis. The engine will have to be lifted the same 6.5mm to sit as it was intended inside the engine bay of the car's body (otherwise the V8's blower will not protrude out the top of the bonnet properly)...

Er, oops! Solving one problem simply creates another. Raising the car's body
off the chassis means that the V8 engine is now too low and the blower no
longer protrudes - as it should - out the top of the bonnet. Bummer!

The same is true for the other engine components - like the radiator - and I will have to raise all these up because of the chassis modifications.

Phew! And that's the chassis modifications complete and it's ready to paint. Although it also became apparent - while doing the above test fitting - that I needed to now move the engine forward to compensate for my moving the chassis back (shortening it)! Every modification seems to result in a knock on effect!

Right, everything has been moved, raised, cut, shut, shifted, tweaked and otherwise
mucked about with. Now I have to tidy up, sand smooth and paint.

And that's that for now.

Next: The big job - modifying the Willy's Coupe bodywork for that 'Mad Max' look!