Design wisdom — Minor variations in results may arise with different versions. They will generally be unimportant. But it is also possible for one incorrect parameter to ruin the entire calculation or even prevent the program from working. Computer programs are inflexible and curmudgeonly, and always contain errors, so if there is a problem and you are sure your data is correct, contact your technical support engineer. The units used in this book are predominantly metric (mm, Nm, etc), as a reluctant concession to the metric majority, and as a mark of respect for the unarguable virtue of conformity in engineering units. However, TJEM’s preference is the English or Imperial system of units, (partly because of the familiar appropriateness of scale, and partly because of the power of fractions.
For example, 1½ pounds per square inch seems easier than 20,700 newtons per square metre). So inches and other English units appear here and there, often in places where points can be scored against the awkwardness of SI units. Alas, the shaku is not used in this book, but it would be fun to try it.
Design wisdom — In a mathematical equation, units are strictly superfluous. In an engineering equation, units are a sine qua non. modulation), RMS (root-mean-square), and p.u. (per-unit). But PM (permanent-magnet) is used sparingly (to avoid confusion with Prime Minister, or post meridiem. The TEMPLATE EDITOR is referred to as Ted (though Hid might be more descriptive), and individual pages by the form Ted/Electrical, etc. Latin phrases such as mutatis mutandis, ad hoc, etc. are used wherever possible— the Romans were engineers too, and they are still around.
The SPEED part of the book refers to the program functions using short-cut keys, and only occasionally spells out the full menu item. For example, Static design is executed using [Ctrl+2], which is more concise and efficient than the cumbersome menu descriptor [Analysis | Static design]. It is recommended to learn the short-cut keys, especially the main ones. The WinSPEED manual provides a list of them, but they appear on the menus, so the only excuse for not using them is laziness.
Notation: Parameter names in SPEED are generally limited to 8 characters. There is no consistent naming convention, and there are significant differences in nomenclature between the individual SPEED programs (mainly because the originals were written at different times). T can mean torque or temperature; R can mean radius or resistance. W is often used for losses in watts (having a connotation of “waste”); but it might also mean width. Both prefixes and suffices are used, often inconsistently: for example, you might find wSlot or SlotWid both referring to the width of a slot.
Fonts: This work is set in 10pt Nimrod MT to save paper, and because of its kerning qualities in equations. Boldface is used for parameters appearing in the SPEED programs, such as Rad1 or Tph. The equivalent mathematical descriptor may be written in the classical form, so Tph becomes Tph. Non-numerical parameter values are written in ordinary type, as for example in Drive = Square. In this example, Drive is the parameter name, and “Square” is the value which will appear in the edit field in the TEMPLATE EDITOR, Ted. Menu items are written in boldface sans-serif, e.g., Analysis | Static design. Short-cut keys are written in boldface enclosed in brackets: [Ctrl+1]. Italics are used for emphasis or for special terms like Dynamic design, which is a complete process, not simply a menu item. Main SPEED windows are in small caps, e.g., DESIGN SHEET, WINDING EDITOR.
Learn the parameter names (and their meanings, which are given in the reference manuals). Don’t guess. A smart programmer might be tempted to rationalise it all, creating even greater chaos, for the SPEED documentation will never be rationalised in this way. The mathematical conventions are followed more faithfully: for example, lower-case letters are used for instantaneous quantities like v or i, while boldface is used for phasors, which are complex: thus V or I.
Abbreviations: Generally acronyms are deprecated, except classical ones, e.g. “i.e.”. It would be churlish not to use common engineering abbreviations like PWM (pulse-width
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