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Adding a tangent to a 22" radius curve

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  • Member since
    April 2003
  • 305,205 posts
Adding a tangent to a 22" radius curve
Posted by Anonymous on Wednesday, July 23, 2003 10:10 AM
I'm trying to modify a track plan from a book, and I'm not quite sure how to do what I want.

I have a 22" radius curve in the 'as published' plan. I want to add a spur, by replacing the first curved section with a turnout. (The straight path through the turnout will lead to the spur, the curved path will lead into the existing curve) But I'm not sure what type of turnout (#4 or #6) and subsequent pieces will be needed to allow me to get back in sync with the plan.

I have some leeway to play with; there are six 22" curves in this segment of track, and I could replace anywhere from just 1 (for the turnout) to all six, depending on what gave me the smoothest curve through this area.

I'm sure if I had all the track in front of me I could try test-fit things to see what felt about right, but I'm still in the planning stages of the layout.

Thanks
Mike
  • Member since
    April 2003
  • 305,205 posts
Adding a tangent to a 22" radius curve
Posted by Anonymous on Wednesday, July 23, 2003 10:10 AM
I'm trying to modify a track plan from a book, and I'm not quite sure how to do what I want.

I have a 22" radius curve in the 'as published' plan. I want to add a spur, by replacing the first curved section with a turnout. (The straight path through the turnout will lead to the spur, the curved path will lead into the existing curve) But I'm not sure what type of turnout (#4 or #6) and subsequent pieces will be needed to allow me to get back in sync with the plan.

I have some leeway to play with; there are six 22" curves in this segment of track, and I could replace anywhere from just 1 (for the turnout) to all six, depending on what gave me the smoothest curve through this area.

I'm sure if I had all the track in front of me I could try test-fit things to see what felt about right, but I'm still in the planning stages of the layout.

Thanks
Mike
  • Member since
    September 2002
  • From: Nova Scotia, Northumberland Shore
  • 2,479 posts
Posted by der5997 on Wednesday, July 23, 2003 8:28 PM
Mike: I think that a #6 will do the trick, but you are left with the 22" radius following the #6's curved branch. Are you stuck with the 22" radius track sections, or could you use some flex track? With the flex track you could draw whatever tangent suits your plan, and build it exactly as you've drawn it. The other 22" radius sections may fit into your plan elsewhere. An alternative, if you simply can't bear not to use the 22" R section at the turnout is do a little surgery on the underside of the plastic ties. Remove sufficient of the parts under the rail between the ties so that the track can be bent to a different radius, and so give you the tangent you want. Hope this helps. It's just my guess, and there may be wiser counsel out there. Have fun!

"There are always alternatives, Captain" - Spock.

  • Member since
    September 2002
  • From: Nova Scotia, Northumberland Shore
  • 2,479 posts
Posted by der5997 on Wednesday, July 23, 2003 8:28 PM
Mike: I think that a #6 will do the trick, but you are left with the 22" radius following the #6's curved branch. Are you stuck with the 22" radius track sections, or could you use some flex track? With the flex track you could draw whatever tangent suits your plan, and build it exactly as you've drawn it. The other 22" radius sections may fit into your plan elsewhere. An alternative, if you simply can't bear not to use the 22" R section at the turnout is do a little surgery on the underside of the plastic ties. Remove sufficient of the parts under the rail between the ties so that the track can be bent to a different radius, and so give you the tangent you want. Hope this helps. It's just my guess, and there may be wiser counsel out there. Have fun!

"There are always alternatives, Captain" - Spock.

  • Member since
    April 2003
  • 305,205 posts
Posted by Anonymous on Wednesday, July 23, 2003 9:55 PM
Mike,

If you want to take the shortest path to get the plan done well, you should use a piece of flex track. There are a few difficulties with what you are attempting to do.

First, the nearest turnout for what you are doing is a No. 4. The Atlas No. 4 Customline turnout has a substitution radius of 36 inches and a curve of twelve and one-half degrees. The No. 6 by Atlas has a substitutiion radius of sixty inches and a curve of nine and one-half degrees. Eight pieces of Atlas 22 inch radius track make up a 180 degree curve so each piece has a curve of twenty two and one-half degrees. If your plan has six pieces of 22 inch radius track, then it curves around 135 degrees over the length of the six pieces. To get the curve to come out to the 135 degrees using the No. 4 turnout, you would use five pieces of 22 inch radius track, one No. 4 turnout and one piece of track with an angle of ten degrees. It turns out that there is a piece of track with an angle of ten degrees and a radius of 18 inches.

But the best way to make a smooth flowing curve is to place the turnout where you want and then put one or two pieces of flex track in to fini***he curve. All you do is trim the inside rail to length with the proper tool (I use a Xuron Rail cutter) and you are in business. Many guys here would be happy to explain further if you want to take this path.

Good Luck - Ed
  • Member since
    April 2003
  • 305,205 posts
Posted by Anonymous on Wednesday, July 23, 2003 9:55 PM
Mike,

If you want to take the shortest path to get the plan done well, you should use a piece of flex track. There are a few difficulties with what you are attempting to do.

First, the nearest turnout for what you are doing is a No. 4. The Atlas No. 4 Customline turnout has a substitution radius of 36 inches and a curve of twelve and one-half degrees. The No. 6 by Atlas has a substitutiion radius of sixty inches and a curve of nine and one-half degrees. Eight pieces of Atlas 22 inch radius track make up a 180 degree curve so each piece has a curve of twenty two and one-half degrees. If your plan has six pieces of 22 inch radius track, then it curves around 135 degrees over the length of the six pieces. To get the curve to come out to the 135 degrees using the No. 4 turnout, you would use five pieces of 22 inch radius track, one No. 4 turnout and one piece of track with an angle of ten degrees. It turns out that there is a piece of track with an angle of ten degrees and a radius of 18 inches.

But the best way to make a smooth flowing curve is to place the turnout where you want and then put one or two pieces of flex track in to fini***he curve. All you do is trim the inside rail to length with the proper tool (I use a Xuron Rail cutter) and you are in business. Many guys here would be happy to explain further if you want to take this path.

Good Luck - Ed
  • Member since
    September 2002
  • From: N.W. Ohio
  • 166 posts
Posted by nslakediv on Thursday, July 24, 2003 8:55 PM
Yep, Give up the sectional track pieces and fill in with flex track. You will be suprised how easy it is.
  • Member since
    September 2002
  • From: N.W. Ohio
  • 166 posts
Posted by nslakediv on Thursday, July 24, 2003 8:55 PM
Yep, Give up the sectional track pieces and fill in with flex track. You will be suprised how easy it is.
  • Member since
    April 2003
  • 305,205 posts
Posted by Anonymous on Wednesday, July 30, 2003 10:15 AM
Thanks for the suggestions. I'll lay out the curve originally using the 22" radius pieces, to mark the intended path, and then replace these with the turnout and flextrack.
  • Member since
    April 2003
  • 305,205 posts
Posted by Anonymous on Wednesday, July 30, 2003 10:15 AM
Thanks for the suggestions. I'll lay out the curve originally using the 22" radius pieces, to mark the intended path, and then replace these with the turnout and flextrack.
  • Member since
    September 2002
  • From: Nova Scotia, Northumberland Shore
  • 2,479 posts
Posted by der5997 on Wednesday, July 30, 2003 8:43 PM
Way to go. I think that will do the trick.. Once you get the flex track down, you may just use the 22 s for templates! [;)] BTW, it's a good idea when using flex track on curves (why else use it did I hear someone think?) to solder the railjoints rather than just relying on the joiners to hold the curve. What happens often is that the pressure of the curved rail on the joiner results in a kink rather than a smooth flowing curve.

"There are always alternatives, Captain" - Spock.

  • Member since
    September 2002
  • From: Nova Scotia, Northumberland Shore
  • 2,479 posts
Posted by der5997 on Wednesday, July 30, 2003 8:43 PM
Way to go. I think that will do the trick.. Once you get the flex track down, you may just use the 22 s for templates! [;)] BTW, it's a good idea when using flex track on curves (why else use it did I hear someone think?) to solder the railjoints rather than just relying on the joiners to hold the curve. What happens often is that the pressure of the curved rail on the joiner results in a kink rather than a smooth flowing curve.

"There are always alternatives, Captain" - Spock.

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