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Old 01-10-2015, 12:24 AM
Kabous Kabous is offline
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Join Date: Jun 2011
Location: Stellenbosch, South Africa
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Hi Scott

As there are some critical steps when measuring for the buck, I will attempt to answer you first and follow up with the rest. Might look complicated but is quite easy, really.

The measurements were taken from the tip of the steel rod where it pressed against the body to where it enters the first wooden post – the second post is only to make sure the rods are perfectly level and lined.

Rail bottom.jpg

Normally it is best to keep things as simple as possible and that is why I used the inner post to measure against as this was both the baseline from the rear of the car to the front (A) and the baseline (B) for any measurements taken vertically of the horizontal wooden arm

Once you have all the measurements, Excel is your friend because you need to subtract and add quite a bit. Before we go into that, first something about the setup because that is very important.

I used two rails for the same reason there are two wooden posts - to make sure the ‘railcar’ runs true and keep the measurements honest

The position of the rails must run exactly parallel from the middle of the car lengthwise and don’t assume the middle of the GT stripes are it. Use a straight edge over the width of the body (level it) and use a builders square or other device and place it at the outside of the rear wheel wells (just touching it) exactly above the middle of the hubs. Measure and middle the straight edge and thus the car. Do the same with the front (do whatever you must but make sure the car is level too).

Position the rails so that the inner post will miss the rear wheel well by say 1/2 inch. The front wheel well will (if rails are placed exactly parallel to the middle of the car) be missed by much more. You can check if it is parallel if the rod (last one on the horizontal wooden arm positioned over the middle of the car) is lowered and land on both the marks you made (rear & front) with the straight edge.

Now you have squared the rails with the car. From that baseline you must put rails in the front and rear of the car at 90 degrees. You have to be creative to measure all the nooks and crannies when doing the front of the car. Very important here is that you mark the car somewhere in the middle of the hood (and boot) when you do your measurements during the length of the car because you need to establish an orientation point to make sense of the measurements taken from the front and rear. By that I mean the distance from the orientation point to the first post when the railcar is positioned in the front or rear of the car.
Another way is to make sure that your baseline (A) when measuring the front or rear is marked off on the long lengthwise rail so that can be used to make sense of the data taken.

Establishing the middle of the car is very important because once you have worked out all the data and transfer it to the whiteboard, the middle of the board then becomes the baseline because there is no other straight line to work from. So when you measure the top areas (boot & hood) make sure you know exactly the measurements from the middle of the car to the (B) baseline.

Baseline (A) would be on the same level as the lowest part of the body of the car that has a straight line (the zero on the first post wasn’t used – the exhaust was in the way but measured from the ground it was exactly the same height. The zero rod length was determined by using a plumb-line from the body to mark the ground and measure it back to the baseline (A).

Don’t use the absolute lowest point (back of rear fender) as this is a once-off point that doesn’t offer anything else. It will have a negative value as it is lower than zero.

Ok so back to making sense of all the measurements taken .

Let’s use the lowest rod in the pic and say for arguments sake its was exactly 6 inches from the tip to the inner post (C)
It was 2 inches from zero (vertical (D)).
The height of the inner post from baseline A to where it meets the horizontal measuring arm is say 30 inches - basically baseline B (E).
From baseline B to middle of the car (last vertical rod) is 32 inches (F)
And lastly, the rod measurement, from the underside of the horizontal wooden arm , 1 foot to the top of middle of the car (G)

On the whiteboard it will look like this:
The line in the middle of the board (top to bottom) determines the height of the middle of the body so because baseline A was the lowest point (zero) on the body, plotting the highest (H) will be like this: H= E-G (30-12) = 18
If your board was marked in inches, count to the 18th inch line from the bottom and mark it.

To plot the side of the car(I): I = F-C (32- 6) = 26
Because I was measured 2 inches from baseline A, on the hardboard go to the second inch line from the bottom, measured 26 inches from the middle and mark the sport.

Do this for all the measurements and duplicate for the other side. Now you have your outline and use a flexible ruler to connect the dots so that the curves are not broken/sharp somewhere.
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Last edited by Kabous; 01-11-2015 at 02:37 PM.
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