Scale

[Dan WalkerParticipant @danwalker]

Hi guys,

I’m building a model where its 1/12th scale which obviously is 1 inch per foot on the real thing. Ive never worked in inches and dont feel comfortable with the imperial system. Is there anyway i can convert this to metric with ease?

I am using rnli drawings to build the trent kit which are at 1/20th scale. i know that i need to multiply any measurement on the drawings by 1.66 to get the 1/12th length but this is all inches.

Would appreciate any help!

Dan

[Paul TParticipant @pault84577]

Hello Dan

I was lucky enough to have learnt my trade during the changeover from imperial to metric so I am one of the happy breed that is fluent in both types of measurement. But when I am converting 1:12 to metric I find that using 25mm = 1 inch quite a good rule of thumb guide.

And before the engineering police jump up and down I do realise that the true conversion is 25.40mm = 1 inch and I will qualify my comments by saying that if I am working on a large model where increments of error can become critical then I always convert to 25.40mm (simple on the calculator)

I also cheat a little by using a digital caliper that works in both imperial and metric so I can just switch very easily between both sets of measurements.

Hope this helps you Dan

Paul

[Bob Abell 2Participant @bobabell2]

Can I but in?……………Just to be pedantic……..1/12 scale is not imperial or metric

1mm = 12mm …………..and 1" = 12"

Just being silly ……….lol

Silly Bob

[Bob Abell 2Participant @bobabell2]

In other words

Multiply the drawing by 20….to get full size

Then divide by 12…….to get the model size

Bob ……feeling clever now

[Paul TParticipant @pault84577]

Ah Bob

Confucius say that there are many ways to skin a cat.

Paul…..feeling un pedantic 

[Dan WalkerParticipant @danwalker]

right so my model is 48" long, that makes it 121.92 cm long in metric at 1/12th scale

now would i use the same conversion factor of 1.66 from the 1/20th drawings to get to the 1/12th measurement if i used the metric system?

confused dan

[Bob Abell 2Participant @bobabell2]

Dear Confused Dan

Just read my post………………multiply drawing size by 20 then divide by 12

Metric doesn`t come into it!

Bob

[Paul TParticipant @pault84577]

Dan

The rule of thumb works very well at 1:12 but at 1:20 I am sorry to say that Bobs system comes into play.

Paul

[andrew hustlerParticipant @andrewhustler]

Hi guys ,how do i work it the ohther way around to work out the scale of something that you have already built .My leander comes in at 4ft 10" in length and a beam of 8 inches i’ve been old that it’s 1/72 scale ,roughly.I have the exact details and they are follows

 Length  267 ft 10" (81.6m)

 Beam      48ft    4"  (14.7m)

 Draught   21ft 9"     (6.6m)

Have i got the right scale

Many thanks

Andy from Cardiff

[Bob Abell 2Participant @bobabell2]

Hello Andy

Your model is 58 " long

The full size ship is 267`-10"..which is…….3214"

Model scale is….3214 divided by 58 = 55:1

Bob

[TelstarParticipant @telstar]

Hi … Isn’t it strange if you use the beam measurements

Full size 48’4"      580"

Model       8"

Scale 580 /8 = 72.5

just a though

Tom

[Bob Abell 2Participant @bobabell2]

Well that`s a sad state of affairs!

So the beam should be 10.5"

No wonder Andy was confused!

Bob

[andrew hustlerParticipant @andrewhustler]

I’m still confused !!!!!!!!!!!! as this is my first attempt at something on this size it’s good to learn from mistakes on the original plans it was 30",75cm,x 4" ,10cm. So i just doubled the sizes to get these measurements .As i said it’s my 1st attempt and I’m quite pleased even if it’s not to an exact scale but it looks good and we all learn from our mistakes said the dalek getting off the dustbin !!!.Next time i will know or rather leave flying to the birds !!!!

But the idea is it’s a hobby to have fun no matter who or what you are.As i’m on a severe budget,Mr brown dont pay that well !!,would it be possible to use cardboard sheet for the bulkheads and coat them with tissue paper and sand and seal or just wait and buy proper ply ??

Many,many thanks for everyones help

Andy from cardiff

[Bob Abell 2Participant @bobabell2]

Hello Andy

Hope you`ve not started yet………..30.75 x 2 ain`t 58!………it`s….61.5!

Oooops!

Bob

[Bob Abell 2Participant @bobabell2]

Andy

I`ve misread your dimensions..

…..It should read…..2 x 30 = 60…………….ie..not 58

Bob

[andrew hustlerParticipant @andrewhustler]

Hi bob OOOOPS!!!!!!!!!!!! is about right as she is 3/4 built but i have just noticed that the bridge is slanting to the left so off it must come and be replaced.I now know that she’s not to a scale that i thought but we all make mistakes as we go along and I’m sure I’m not the first or last.The plans I’m working from,roughly,were drawn up by Vic Smeed back in 1975 for the BBC TV  serise Model World hosted by Bob Symes who had a magnificent railway layout in his back garden.

For my next project i would’nt mind building the police/harbour patrol launch that runs up and down the river Taff here in cardiff.It looks to be quite simple,famous last words !!!,and has a shallow draft and looks to be proppeled by water jet rather than a conventional prop.

Any Bob many thanks for yourr help and advice and i hope you dont mind me giving you a shout if i have any more problems or questions.

Many thanks  

Andy from Cardiff

[Bob Abell 2Participant @bobabell2]

No problem Andy……….Any time

All the best……Bob

[Dan WalkerParticipant @danwalker]

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