Tuesday, 16 May 2017

Measure For Measure

I saw a discussion online recently where a young narrow gauge modeller was thrown to the lions for asking for confirmation that in OO9 4mm equalled a foot.

As one has come to expect on social media this person was mocked and condemned for their ignorance, and the lack of initiative for asking the question in a post rather than researching the answer themselves.

However it made me realise that those of us who scratch build or work from drawings on a regular basis probably take it for granted how many conversions and calculations me make as a matter of routine.

As well as scaling down the dimensions we also have to convert between metric and imperial repeatedly.

Even the scale I'm working in - 4mm - is a mix of the two.

So take, for example, a model I might decide to make of one of the FR's latest carriages.

These days they're designed using metric measurements, expressed in mm.

So my first task is to convert this to an figure in feet and inches and then scale it down and get a value based on 1 mil for each 3 inches.

(I'm not too proud to admit that a calculator is involved at this point.)

That is not the end of the process, either,  because when I come to make my model - in metric - I'm building it using styrene strips from America which are sold according to imperial sizes.

So, for example, if I need a strip to be 1mm wide (a scale 3 inches) then I need to reach for the packet with strips that are 0.40 thou of an inch thick.

It's no wonder people who are relatively new to the hobby go online in search of answers, is it?


  1. While mocking and condeming someo fro ignorance has no place in our hobby, I do understand the lack of sympathy when faced with yet another person who can't be bothered even to look something up. Most of the time, the answers are easy to find and yet it's even easier to throw a question out there and expect everyone to spoon feed you. I see a lot of this on Facebook. There are resources out there - books, magazines and even websites so why do a tiny number of people refuse to use them?

  2. Whilst I agree the resources are out there, we can all too easily forget that we too are a resource.
    Whilst some would consider it lazy, others may see it as using ones initiative. At the end of the day, one doesn't have to reply.
    If you asked a teacher a question as a child, did they lean back and tell you to go to the library to find out the answer on every occasion?
    In my experience, knowledge can be found in a wide variety of places, including the student who 'appears' to know nothing.
    I appreciate that not everyone has the patience to teach, but everyone can remember to show some modicum of respect.
    "We are not teachers, we are fellow travellers from whom other ask directions"

  3. Sometimes I was told to go and look stuff up. It's the old "give a man a fish..." thing. Constantly answering questions means you'll be constantly answering questions. Pointing the questioner in the direction of useful resources occasionally helps both of you.

  4. It might be a daft question, but when working from a drawing of a prototype in mm, why not just divide the measurements by 76 to get straight to the model size? Of course, a calculator is still needed!

    1. Because i'm not very clever and I never thought of that.