 Home Calendar Speedsters Event-Photos Engines Technical Construction John-Blacks-#917 WoodCars Model-A-Chassis Speedster-Design Analysis Overview Software Creating the Shape Constraints Measuring Narrow Frame Widest Point Curve Top Curve Radiator Curve Mid-Car Curve Rear Curve Skirt 6 Designs Survey Planking CNCRouter Model Strongback Strip-Building Bodies Heads Carbs Water-Pumps HighPerformance RearEnd-Tranny Front-Ends Wire-Wheels Engines All-Vintage-Ford Clubs-Museums Racing Hill-Climbs Endurance-Runs GreatAmericanRace Historics Automobilia Organization ContactUs |
|||
|
Speedster Design Overview |
|||
| Fair Lines | |||
| Good looking Speedsters have Fair Lines. "Fair" is a mathematical concept. Software like Rhino can give you fair lines. Fair lines result when the line or curve is shaped by the smallest possible number of control points. | |||
 |
 |
 |
|
| A straight line is a 1 degree curve shaped by 2 control points. | A 'C' shaped curve is a 3 degree curve which can be defined by 4 control points. | An 'S' shaped curve is a 5 degree curve that can be shaped by 6 control points. | |
| When creating curves you may use more control points, then rebuild the curve so that Control Points = Curve Degree + 1. Extra control points and "knots" need to be dealt with to get fair curves. Built in Fairing functionality also helps. | |||
| Speedster Design Basics | |||
|
Speedsters are designed thinking about half the
body. The other half is created with a mirror copy.
Most speedster curves are 3 degree curves defined by 4 control points. Speedster Bodies are defined by the Radiator Curve, a Rear Curve, and one or more MidCar Curves ... often the firewall and a curve near the back of the seat. Lengthwise curves require 4 points. As an example consider the red frame level body curve drawn below and its 4 control points that are connected with a dotted line. |
|||
|
|
|||
| The simplest Speedster Body has 3 Curves. The rear curve is positioned aft of the actual rear end of the body and across the center line. When the body is lofted across the 3 curves, the portion of the body across the center line is trimmed away. This shape is then mirror copied. | |||
|
As a simple example, consider this Speedster which is Shaped by 3 curves. The Radiator Curve A single Mid-Car Curve The Rear End Curve |
|
|
|
|
These 3 curves below give this body. |
|||
|
|
 |
||
 |
 |
||
 |
|||
|
The reflective surface shows that this body is mostly fair. Notice that the frame is sticking out of the body both front and back. In front, if the lofted body will be cut away for an open sided engine compartment. In the rear there are choices : Let the frame stick out, narrow the frame, move the mid car curve back to widen the rear body, move the rear end curve, reshape the rear end curve, reshape the mid car curve, or insert curve(s) between the mid car curve and the rear end curve. One or a combination of these approaches will yield "The Design" you like. |
|||
|
Home || Calendar || Speedsters || Events || Engines || Technical || Historics || Organization || Contact Us |
|||
|
Copyright 2002 and succeeding years -- Northwest Vintage Speedsters |
|||
|
Suggestions or Comments on Our Web Site ? |
|||
