I’m sure its been published many times, but now that I need the information I can’t readily find it, either in my back issues of MRM or on this website. Nevertheless, how can I quickly translate HO scale grades (i.e. 2%, 4%, 9%, etc.) into real feet and inches (?" rise for every ?" in length) so I can cut the risers I need for my roadbed? If someone will point me to the formula I promise to print it out and add it to my MRR notebook. Thanks.
Well I do know that a 1" rise in 100 inches is 1%, .5 in 50 inches = 1%, 1 in rise in 50 inches = 2% etc. That aught to get you going anyway.
Terry[8D]
One more thing, grades don’t change with scale. A 2% grade in HO is exactly as steep as a 2% in N scale.
Thanks. I think I understand now.
Follow the link under my signature. There is a grade chart you can print out.
You can approximate the N% grade as N inches in 8 feet (96"). This will give you N/8" every foot and N/4" every 2 feet. The grade is slightly steeper, but the calculations get easier.
claycts nice grade chart.
Thank you, [:D]
This is one application where metric comes in really handy.
A 1% grade is one centimeter every metre travelled. 2.5% would be 2.5cm for every metre, or about 1 inch for every 39 inches.
The only tricky part is conversion to inches: 25.4mm or 2.54cm equals 1 inch. A foot is about 30.5 cm (or 305mm).
The calculation is simple.
Grade = rise over run. For percent grade, multiply that number by 100. So a rise of 3" in a run of 50" is: 100 X (3/50) = 6 per cent grade.
Note that there is no scale associated with it - 1" rise in 100" run is one percent, whether you’re in HO, N, G or any other scale, including 1:1.