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Half Loop Radius

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Half Loop Radius
Posted by Bayway Terminal on Sunday, October 18, 2020 11:32 AM

What demensions should the bench work be if im planning a 24'' or 36" inch elevated curve connecting from an existing single lead track ?

The planned track extenstion will be exiting an existing flat surfaced yard area, and this initial layout expansion will start by using sections of flex track with no turnouts involved, just an elevated half-loop radius / which will expand my shelf layout eventully by another 15 ft or more, but first i will need to make this right turn due to a basement wall. 

Note: At the very end of the planned 15 ft. shelf expansion i'm planning a 24" or 36" circle loop.  Bayway Terminal NJ         

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Posted by cuyama on Sunday, October 18, 2020 1:01 PM

The width of the benchwork needed is twice the radius plus the width of the track and ties, plus clearance and safety margins to walls or aisles.

Byron

 

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Posted by Lastspikemike on Sunday, October 18, 2020 7:49 PM

Right turn of 90 degrees or 180 degrees? That is are you turning 1/4 of a circle or half a circle?

To make a 90 degree turn from your yard to an adjoining straight section can take a lot less space than you might think. 

Alyth Yard

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Posted by doctorwayne on Sunday, October 18, 2020 10:14 PM

Lastspikemike

Right turn of 90 degrees or 180 degrees? That is are you turning 1/4 of a circle or half a circle?

To make a 90 degree turn from your yard to an adjoining straight section can take a lot less space than you might think. 

 

 
It would help to understand what you wish to accomplish if we had a photo for reference.
 
The benchwork, especially for a 90º curve, doesn't have to be much wider than the track itself, although if it's in a corner of the room, it would make sense to also fill the space between where the walls meet and where the track curves.
 
Wayne
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Posted by SeeYou190 on Sunday, October 18, 2020 11:33 PM

Bayway Terminal
Note: At the very end of the planned 15 ft. shelf expansion i'm planning a 24" or 36" circle loop.  Bayway Terminal NJ   

NOTE: This is not my area of expert knowledge, so when Byron responds and tells you what I am wrong about... listen to Byron.

I assume you are in HO scale, and what you are planning is a return loop at the end of the layout.

These things are space eaters. The drawing below shows how much space is needed for 22 inch radius curves in HO scale, you can see it is almost 4 foot by 8 foot. If you put one on each end, that will be all of your 15 foot length. On one side only, and you lose almost half of your usable space.

I hope this helps a little.

-Kevin

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by Bayway Terminal on Monday, October 19, 2020 1:12 PM

Respectfully if I clould learn how to post photos i certainly would, Bayway Terminal  

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Posted by Bayway Terminal on Monday, October 19, 2020 1:28 PM
Your return loop plan will be useful, but will not occur until the very end of the layout expansion, first i need to make a right turn coming off an existing out-side lead for out - bound traffic. The existing inside lead track is 22 inches opposite the out bound described, and the overall out-side dimension of my shelf layout is 36 inches. This being the return loop connection for inbound traffic back to the existing industrial yard will have to be taken into consideration as well. Bayway Terminal NJ
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Posted by Bayway Terminal on Monday, October 19, 2020 1:34 PM

90 degrees / but gradually elevated. I need to turn a corner due to a basemmet wall in the way. , i would prefer a 22 or 30 degree radius curve . Bayway Terminal  

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Posted by jjdamnit on Monday, October 19, 2020 1:39 PM

Hello All,

Bayway Terminal
...if I clould (sic) learn how to post photos i certainly would...

How to Post a Photo to the Forums

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by Bayway Terminal on Monday, October 19, 2020 1:49 PM

Thanks, i will need to study your plan in and try to conceptually apply it, initailly i will need to install (45 degrees) of the 180 drgree radius you provided, or 1/4 of a 360 degree circle / as a right graduating elevation turn / without a switch, RE: flex track .

Bayway Terminal         

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Posted by cowman on Monday, October 19, 2020 6:57 PM

To post photos, go to the General Discussion section of these forums, first one.

My problem is getting the photos from my camera to the computer.  (Yes, a camera.)

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Posted by riogrande5761 on Tuesday, October 20, 2020 7:36 AM

cowman

To post photos, go to the General Discussion section of these forums, first one.

My problem is getting the photos from my camera to the computer.  (Yes, a camera.)

In my experience, typically there were two ways of getting digital pictures from a camera to a computer.  A USB cable is traditionally used to connect the two devices together.

1) Cameras usually come with software that will give you control over moving the pictures to the computer.

2) When you plug your camera into the computer via the USB cable, it will show up in your directory (Windows Explorer or This Computer) as an additional drive (like a flash drive).  You simply navigate to the folder where the pictures are stored and copy/paste them to a folder on your C: drive.

These days I mostly take pictures with my smart phone.  In that case I navigate to the pictures on the phone and choose "share" and the use my gmail to email the pictures to my self.  Then I go to gmail on the computer and copy the attachments to a folder on the computer where I can upload them to a photo host or other things.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by Lastspikemike on Tuesday, October 20, 2020 2:07 PM

From the context I inferred you were looking for some formula for a 90 degree bend in an along the wall layout.

Doing that myself as we speak.

Interestingly and counterintuitively you need less space if you build a 90 degree larger radius curve. 

I first drew mine with a set of compasses (you recall those are included in your high school geometry kit) trying different radii at different foci.

The smaller the radius the further into the corner it will fit but you're already starting with x width of your yard. The largest radius will be the one that comes closest to the inside corner of the 90 degree adjoining shelves.  Make that an angled 45 degree cut instead of 90 degrees and you'll find even more room.  Other angles that in effect fill in the inside corner can get you more flexibility in alignment with no real penalty in shelf intrusion into the room.

To get the largest radius you start at the back wall of one shelf and bring the curve as close as you can to the inside corner before curving out to the back wall of the other shelf. Depending on your main line alignment running past or through your yard you can easily get more than a 36" radius into 18 inch wide shelves. 

I recommend you draw the shelves and set your compasses at the desired scaled radius and just try a few arcs.  The desired alignment will pop into view quite quickly.  

Alyth Yard

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Posted by wjstix on Tuesday, October 20, 2020 4:00 PM

Lastspikemike
Depending on your main line alignment running past or through your yard you can easily get more than a 36" radius into 18 inch wide shelves.

I agree. The 'around the walls' part of my layout uses 16" wide shelves attached to the wall; I was able to fit Kato's 31-1/8" radius (HO) curves on a 90-degree corner turn and could have fit in a bit larger. I would think 36"R would fit on 18" wide shelves quite nicely.

Stix
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Posted by Lastspikemike on Tuesday, October 20, 2020 6:57 PM

For a 180 degree return loop the minimum radius rules but you can compress the "length" a little if you accept the dreaded S curve. Again, it helps to break out the compasses and draw a few intersecting arcs. Then see how short a tangent (the straight track part connecting the end if your return loop to the returning mainline along the wall) will get you the right reverse curve to complete your loop to rejoin the main line.

Basically, you build about 270 degrees of return loop to get the needed 180 in the shortest space lengthwise. There is no way to squeeze the 180 part into less than 2x minimum radius. There is no way to squeeze the long direction of a return loop in under 2x minimum radius plus the section needed to get your main line back to the shelf. 

Of course, if you keep going around the room.....

Alyth Yard

Canada

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Posted by FlattenedQuarter on Tuesday, October 20, 2020 7:33 PM

Question, where is the stated radius of a curve measured on a piece of track? Inside rail, center of track, outside rail?

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Posted by davidmurray on Tuesday, October 20, 2020 7:53 PM

Radius of a curved track has always been measure on the centre line.

Thus you need to keep it two inchs from a wall or table edge.  Track spacing is measured the same centre line to centre line.

 

David Murray from Oshawa, Ontario Canada
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Posted by Bayway Terminal on Tuesday, October 20, 2020 10:22 PM

Thanks to all for the assistance, I will follow the advice on proceeding with a scale drawing for the right turn radius that works best for my layout expansion . Bayway Terminal NJ

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