Hi All wise ones
Of course I understand HO scale is 1:87 which is 87 of the real thing, Could somebody please give me the mathematical formula of how to scale down several different real life objects ?
eg: If a house is 3mtrs high. how do I convert it down to scratchbuild it in HO scale 1:87.
If I can be shown the formula to convert one thing, I should then be able to convert most things down to build them for my layout.
Thanks again for your wisdom
Tom From Down Under
If you have a passenger car that it 87 feet long, you would divide that 87 by 87 and you would have a model that is 1 foot long (87/87=1)
Now suppose you have the front of a building that is 35 feet wide… divide 35 by 87 and if this computer had a calculator on it I would tell you how wide that would be in HO.
But if you model in inches ( you don’t being down under) you might multiply that 35 by 12 to convert it into 420 inches. Now divide that 420 by 87, and you would know how many inches wide to make your store feont or whatever.
So you use meters… 3 meters / 87 will tell you how big 3 HO meters would be. Or 3000 mm bivided by 87 would give you your answer im milimeters.
Any 1:1 dimension divided by 87 will convert it to HO
ROAR
The Lion has summed it up well, all I would add is if you’re going to do a fair bit of scratch building, buy yourself an HO scale ruler, I find mine invaluable.
Cheers, the Bear.
Fine, bud down under do they make metric scale scales as it were?
I wouldn’t have a clue Lion ! I guess I will have to have a trip to the local hobby shop but it is small and I dont like my chances !
where do you guys over there get yours ?
Maybe online might be an option
Your thoughts?
All of the above is great info!
I would suggest buying Stan’s Handy Converter Software, it has a calculator for everything the model railroaded needs. That is one of the best $20 investment I’ve ever made.
http://www.stanstrains.com/SoftwareHandyConverter.htm
The Converter will convert any dimension to any scale in inches of meters as well as electrical, grades, curves and even a helix.
Check out his Model RR Scale 1:1 converter on his demo.
http://www.stanstrains.com/Demo/HC17ModelDemo2/index.html
I’d be lost without it!
When working from a plan (of any scale) or a photo, as long as you know one dimension you are OK.
What I like to do is figure out the ratio of the plan (in any scale) or photo to the model I’m building then use a dial caliper and a calculator to figure out the sizes for the model. There is some math on the front end, but once I set the ratio, the rest of the measurements go quickly and knowing the the scale of the plan or photo is not necessary.
Find a line of known dimension on a plan. You can use wheel diameters, truck centers, truck wheel base, coupler height, door height or width if its not a measured drawing or is a photo.
On the plan, measure that distance with the calipers. Lets say you know the truck wheel base is 5’6" and on the plan it measures .965". You are building to HO scale. 5’6" is 66" and in HO is 66/87.1=.758"
Find the ratio between the HO dimension and the plan dimension, HO/plan=.758/.965=.785.
.785 is your conversion ratio. Use that for all future measurements from the plan. Meaure any dimension on the plan using the caliper. The height of the car side measures 1.73". Multiply that by the conversion ratio to get the actual size the model needs to be. 1.73 x .785 = 1.36". The car side of the model will be 1.36" wide.
Note that this method works in either English or metric units once you establish the ratio. The plan measures 43.9 mm. 43.9 x .785 = 34.5 mm. The model side would be 34.5 mm wide.
The nice thing about this method is if you use plans you have copied from a book or printed on your home computer you don’t have to worry if the printer changed the scale or the copier resized the copy.
Tomcat,
I have a General No. 1251 HO/O/S “Model Railroad Reference Rule” that I bought when a teenager decades ago. It still serves, although a few of the markings right at the end are getting scuffed a bit, although the etched markings keep the last of the inking visible. The back has English and metric scales, drill bit diameter conversions to both fractional inch and number types, and other misc tapping and screw info.
AFAIK, should still be available. Weight is 30 grams, so postage shouldn’t be much from up here if you can’t find one in the Southern Hemisphere.
I hope this link to this online converter works. Sometimes it does, sometimes it doesn’t.
Tom,
In this link I will provide from NESL, are very handy scale conversion chart diagrams for, N, HO, S and O scale, meters,inches and fractions for all 1:1 lumber and building materials…which You should find very useful, in scratch building and more info. Just click on link…give time to load, it is in PDF format, keep for future refferal.
http://www.northeasternscalelumber.com/uploads/pdfs/NESLCatalog_2013.pdf
Take Care! [:D]
Frank
Gidday Tom, I would presume that the “General 1251” rule that Mike mentions is this one available here…
http://www.casulahobbies.com.au/catalog/advanced_search_result.php?keywords=Scale+ruler&osCsid=a1897b4a5bfe66e7599da4d78df125f5&x=8&y=10
There is also a printable download HO scale rule here…
http://www.printablerulers.net/preview/Hobbyist_HO-scale
Brother Lion, straight off the bat I would have said no, but again I would be wrong. While I was looking for options for Tom, I found this site…
Bear,
Yes, I think that’s the current version as it is listed as the #1251 if you click through it enough. Mine is from before they added N to this model.
Walthers lists it as an out of stock item. Pic is here:
Tom,
Hopefully You will look through that link I provided…It will show a pic of a scale rule #1251…this one is ‘‘Gold’’ plated…LOL, also special tools and a glue that is outstanding for any wood scratch building and even a lot of tips.
The General #1251 I have for many yrs. The HO scale rule side, is in MM also…there is also one on the backside, of same rule, in MM.
Take Care! [:D]
Frank
Hello All,
I use an online calculator from the Garden State Central Model Railroad Club. It’s only available in standard not metric.
Hope this helps.