RE: On the issue of belief in plans, kit

SDW@qld.mim.com.au
18 Oct 95 09:45:00 EDT

Hello All,

Further to Paul and Bills discussion of the accuracy of plans and kits I
have to say that published dimensions are all but useless as well
_unless_ they are marked against a scale drawing.

The problem is that (for example) the length dimensions can be measured
along the fuselage centreline, with respect to the centre line (not the
same thing), along the fuselage datum line, with respect to the datum
line (again not the same thing), along the thrust line, with respect to
the thrust line (yup, same again), or plan length (length projected at 90
degrees onto the ground of the aircraft on the ground)

Thats the seven I've seen, for all I know there may be more. The
diffence between shortest and longest is greatly dependent on whether
centreline, thrust and datum are the same (usually not !) and whether the
aircraft is a tricycle or tail dragger, but is also dependent on the
actual shape of the nose and tail.

Also many dimensions exclude propellors (because different types or
different spinners are different lengths) or include them but don't tell
you which type! Other details like tail lights (not usually in WW1 :-),
are arbitrarily added or excluded.

In our case (WW1 aircraft) you need also recognise that the aircraft may
be up to several inches different in length or span even when built in
the same factory by the same craftsmen. Henry Fords mass manufacturing
techniques had not yet really been applied too stringently back in the
days of craftsman built wooden airframes. This is in part why you often
read of airmen having favourite aircraft - some flew better because the
happy coincidences of aircraft component size and weight.

The bottom line for a modeller is this. Anyone pedantically quoting any
kit as innacurate because of a supposed difference of "inches" in length
or span, or imperfect agreement with published plans is talking what we
colonials impolitely call utter bullshit.

As usual its up to you. I subscribe to the - Looks right, agrees with my
best knowledge, is right, school.

Sorry all, but I have had to get on this soapbox as a judge to protect
modellers from nutcases wedded to a micrometer, and I tend to repeat it
occassionally.

End of sermon. Normal transmission resumes. Bzzzztttt.

Regards

Shane

(most used acronym in this group is AFAIK - I wonder why ?)