# Can't get proper grade



## dfischer (Nov 14, 2012)

I have a subroadbed section I am trying to give a 3% grade to. I figured the run and the amount of rise for each riser and was measuring to the bottom of the sub roadbed. Yet, when I put the subroadbed on top of the risers, and then put my digital reader on the top of the subroadbed, the grade is nowhere near the calculated 3% grade. Am I way off base - just not making sense to me.

Thanks.

dfischer


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## Blackout (Jul 23, 2013)

Is your digital reader giving you degrees or % grade?


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## dfischer (Nov 14, 2012)

It is set for %.


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## dfischer (Nov 14, 2012)

Blackout said:


> Is your digital reader giving you degrees or % grade?


It is set for %


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## eljefe (Jun 11, 2011)

Can you explain your math used to calculate what you built? Have you done any measurements independent of the digital percentage?


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## gunrunnerjohn (Nov 10, 2010)

The grade is simply the rise divided by the run length. If you have a 3" rise and 100" of run length, you have a 3% grade.

3 / 100 = .03 which is 3%.

The calculations are really simple...


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## dfischer (Nov 14, 2012)

*Can't get the Grade*

Thanks to all for responses, but I know how to calculate the grade. I used 3% and calculated the amount each riser should be raised above the tabletop to achieve the 3% at that location. I have risers approx every 2'. The entire run is 12'.

Once I installed the risers, each to its specific height I then laid the sub roadbed (plywood) on top of the risers. I placed my digital scale on top of the sub roadbed and nowhere was I close to the 3%. I rechecked my risers.

The way I measured is from the tabletop up to the bottom of the sub roadbed. But, the scale on top of the roadbed is not showing the expected 3%. So, I am doing something stupid, but can't figure out what it is.

Thanks.

Dan


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## dfischer (Nov 14, 2012)

I just posted a general reply explaining what I have done. To be specific, I just multiplied the distance of the run (at the various riser locations) by 3% to get the amount of rise for the risers. The only measurements I have taken have been with my digital scale for %.

Many thanks.

Dan


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## spoil9 (Dec 24, 2008)

Time for a little math!

General formula: raise/run = grade %

You're run is a total of 12ft, or 144 inches.
so x/144 = .03 --> x=144*.03 = 4.32

So assuming you start at ground level, the track at the end of the 12ft run should be at or less than 4.32 inches. If it's more, than you have more than a 3% slope. 

For each riser, you said they are 2ft or 24inches apart. (On a side note, not sure what scale you're running, but unless you're running plywood as a base there may be some sag between risers which may cause the level to think there is more than a 3% slope at that point)

For 144in run, risers at every 24in, I assume there are 6 risers. Each should be so tall...

1. 0.72"
2. 1.44"
3. 2.16"
4. 2.88"
5. 3.6"
6. 4.32"

Hope this helps. I in no way mean to insult anyone's intelligence with this post. I mean it simply to help anyone in the future who may read it as I know a lot of people just do not like math.


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## dfischer (Nov 14, 2012)

*Can't get the Grade*

Spoil9 -- many thanks. Your math matches mine! The math is not the problem. The problem is that when I install to that math, my end result when I put a digital scale on top of the subroadbed, I don't get close to 3%. My problem is an installation problem, but I'm not sure what! THAT is what I need the help on!!!

BTW, my subroadbed is 15/32 plywood and I can't detect any sags. I have checked and rechecked my riser heights...all match the math! Again, I am measuring from table top up to the bottom of the subroadbed for the height of the riser.

Any ideas?? Thanks to all. You guys are great!


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## kimber (Aug 2, 2013)

Are you working from a level surface? Check the base with the meter.


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## dfischer (Nov 14, 2012)

*Can't get the grade*

Already checked and it is level, so I don't think that is my problem. I've checked it all and eliminated it all. So, technically, I should not be having the problem! Thought maybe there was some secret to this that I was not aware of!


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## Blackout (Jul 23, 2013)

Can you post a side view picture of your grade? How far off are you? Can your measuring tool be in error?


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## BK R (Dec 8, 2012)

I'd be trusting the maths more then a machine, what is it telling you the grade is???:dunno:


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## eljefe (Jun 11, 2011)

I echo the above comments. Have you tested the digital device against something you know the angle of, like a 45 degree triangle for example? Maybe it's out of calibration.


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## BK R (Dec 8, 2012)

An easy test is...measure 100" (8 foot 4 inches) up your track, then check the height...it should be 3"..if it is throw the digital dodad in the bin.


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## gunrunnerjohn (Nov 10, 2010)

I'm with the other opinions, if you're actually doing what you say, your inclinometer isn't working correctly.

Of course, you do have to have a really flat surface that reflects the grade in order to measure it. I don't know what device you're using, or how long it's measuring surface is, but that could be a lot of the issue.


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## Blackout (Jul 23, 2013)

Good point, if the meter has a short measuring surface, that could be part of the problem. Lay a 4 foot long level down first and then place the meter on the level. 

I'm with the others, no need for the meter. When I built my incline, I knew what height on needed the trains to get to, so I computed the distance needed to get to that height given the acceptable 3% grade. 

Love to see a picture, they are worth a 1,000 words.


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## Carl (Feb 19, 2012)

Once you get every thing figured out, then comes the question of 2% versus 3%. Lots of folks try to stay inside of the 2% slope....seems to be an issue of loco's pulling a long consist and loss of "pulling" power as the % slope increases......just a thought.


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## BK R (Dec 8, 2012)

How'd you go??


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