dambrose wrote:This is waaaay to much thinking and MATH.......Just use the biggest radius curves and "eye-ball" it......works everytime. We don't need to follow NASA/Govt. Standards you know..... dan
This is waaaay to much thinking and MATH.......Just use the biggest radius curves and "eye-ball" it......works everytime.
We don't need to follow NASA/Govt. Standards you know.....
dan
Hello Dan,
That is quite true, OTOH if someone would like to know how one measures "whatever" accurately, then it is best to list a few methods which give accurate results.
If any of those methods are then used is a completely different matter. Just a matter of "can it be done?"
ER
Now on to some practical stuff;_
Read this in conjunction with what has been said about my golden palm problem; at this stage i have opted to take the easy but not the most worthwile alternative of going in front of it.
The scene is still my area 1, which i am reworking to make it fit in with my "Ell" development which connects area 3 with area 1. This is now part completed and i am running trains around a loop betwen the three areas but i am only utilising the front half of my reversing loop, which will be refered to as the ascending ramp. (up to the points which switches the train from going around the reversing loop or on to the "Ell")
My ascending ramp is completed and i have a beautiful R2 curve and a very nice gradient of 2 % and it looks correct and works very very well.
Now we are on to the desending ramp, which will go to the front of the palm; at about the middle of both ramps they unfortunately become adlacent to each other. At this point the descending ramp willbe behind the ascending and it should be the same height as the ascending ramp or about a centimetre higher. But as i am approaching this point in building the descending ramp, it is becoming obvious that opposite will be more likely; ie it will be about a centimetre lower.
As i am now working on a gradient of 1.5 % down as against 2 % up, there is not much in it and everything i do must be pretty right.
So i have decided to modify one of my spirit levels (i have 5) to accurately measure 1.5 % gradient. it is 220 mm long ( it is the one mentioned previously that sometimes has 2 bubles) so if i have 15 mm rise in 1 metre, i believe i have a gradient of 1.5 % so if i X this by 0.22 i will end up with about 3.3 mm or for practical purposes 3.5 mm. I have attached a small stepping block at one end of 3.5 mm to check things over minutely.
What do people think? do you agree with my method and calculations?
Rgds Ian
Ian,
The math looks good and the block for the level sounds fine. Since it's a short level it should be able to fit through the corner well.
Jack
Yes Jack you are quite right, i have used this length as i a musing bricks and i want to check each individual brick for gradient and using a smaller level from side to side as well.
A point i omitted previously is that the top of the ramp has just over an R3 curve and the rest is pretty straight, so i want to have the gradient on the straight rather than the curve if i can.
Well i am making headway; i have redone about 10 sets of bricks and i am using this modified spirit level to check out not just the gradient of the bricks but also the gradient from one brick to another and that was where my real problem was.
I have gained about 15 mm (0.6") but i had hoped to gain an 20 to 30 mm (an inch or so) in height at least, but it is 100 % correct and i wil live with it.
Rgds ian
I am now well past the point where the two tracks abutt each other and lo and behold it worked out exactly correct, the descending ramp at the rear is exactly 1 cm higher than the ascending ramp at the front. So the rest of the gradient at 1.5 % should mate precisely with the shorter ascending ramp at 2 %. These are two parts of a reversing loop and they must both start and end at the same place.
I knew you all would be interested.
I'm glad it worked out the way you had hoped.
Yes jack this is quite a complex business as it is a reversing loop i have S09 connected to S10 twice about 7 m one way wand about 11 m the other way, S09 connects the loop up to the main drag and S10 connects to an "L" .
Had you better explained what you wanted you would have had better answers.
I agree with the block and level method, however, I took it one step further so that it will work over varying distances.
I determined that I wanted 1.75% grade on straightaways, and 1% on curves; so I went to local hardware store and picked up a couple of el cheepo plastic framed levels (1 of 4' length and 1 of 2' length), some 1.25" X 1.25" aluminum angle, some small nuts and washers, and a tube of construction adhesive.
Using my handy dandy calculator, I deternined the amount of rise 1.5% would be in the 4' of run and used some nuts and washers to elevate one end of the level that much in the angle. I then clamped it to hold everything steady and pumped the void between the level and the angle full with adhesive. now, when that bubble reads centered, it gives a 1.5% grade either up or down, whichever way you place the packed end of the angle. works on anything from a short distance to the 4' length at a time. for a long run, I do about 4', then shift it about 3' at a time to check longer runs and keep then aligned with the prior section.
Likewise with the 2' level for the 1% grade on curves. I used the shorter length to better accomodate the curveature! Works like a charm.
Have had them for over 4 years now, and they have been exposed to all kinds of weather and banging and have held up like new!
Dear Bob,
Using the KISS method is by far the best way to proceed. If the thread title wouldn't have been "How do you accurately measure gradient on a curve?" perhaps one page of replies would have been quite enough, alas...........
Regards
I don't owe an explanation to anyone, however i posted this subject just to see who knew what they were talking about and who didn't and that has become ubbundantly clear to me.
However as the thread went on, progress an position on my current project changed and other matters came into the the thread. but i can tell you a few blokes really showed up justy how knowledgeable they are like Tom, Jack and Dave.
For those who are interested i am making a concerted effort to learn how to post photographs and i have much more to discuss and any people who find it an imposition to contrinute are hereby invited to not bother.
iandor wrote:I don't owe an explanation to anyone, however i posted this subject just to see who knew what they were talking about and who didn't and that has become ubbundantly clear to me.However as the thread went on, progress an position on my current project changed and other matters came into the the thread. but i can tell you a few blokes really showed up justy how knowledgeable they are like Tom, Jack and Dave. For those who are interested i am making a concerted effort to learn how to post photographs and i have much more to discuss and any people who find it an imposition to contrinute are hereby invited to not bother.Rgds Ian
Dear Ian,
Premise accepted...... but don't forget that model railroading in general, and Large Scale or garden railroading in particular, is still governed by the same laws that apply to the "everyday world" we live in.
Chances are very good that if one paid attention during one's years of education that the knowledge acquired will be applicable to the hobby, too.
In this particular case it was ordinary geometry and straightforward mathematics, applied to a simple problem. No more, no less. Applying High School knowledge in a practical manner.
Kind regards
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