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Laying down curved track

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Laying down curved track
Posted by doug57 on Tuesday, November 16, 2021 7:23 PM

What would be the best way to lay curved HO track? Purchsae the required radius pieces, or solder three sections of flex track together.

Doug

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Posted by doctorwayne on Tuesday, November 16, 2021 9:22 PM

Buying sectional track with a fixed radius may work, if that particular radius meets your needs.
Flex track allows you to make the curves in whatever radii you need, and, of course, it also allows you to create transitions between straight and curved track and also between curves of varying radii.

I've always used flex track or Central Valley's tie strips, with 3' lengths of nickel-silver rail.
For the tie strips, I usually cement them together in 15' (or longer) sections, then affix the ties in place using gelled contact cement.
I then solder the rails together, into lengths suitable for the tie strips that are in place, then secure the rail, again using contact cement.

The first (and last) time I used sectional track was with a O-27 set from Marx, when I was a small kid.

Wayne

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Posted by crossthedog on Tuesday, November 16, 2021 10:56 PM

I strung three 3-foot flex track lengths together. It's tricky, though, because when you curve three 3-foot lengths of soldered track the loose (inside of the curve) rail becomes longer and so the left and right sides of the joint become grossly misaligned. When I soldered three lengths at one time, while straight, then it was impossible to curve the whole 9 feet without removing half the ties to accommodate this offset in the sliding joint (because with the rail joiner the joint cannot slide past the ties).

So to get around this: I soldered two lengths on the bench, while straight, and then laid them in place, tacking them down so the track roughly followed the intended curve. Then I cut the ends of the second length in its curved state before untacking it and letting it straighten. Now straight, the end rails of the second length are misaligned, but they will realign when I lay them in the curve again. Before relaying it, though, I soldered the THIRD length to the second (i.e., while straight). Then I could recurve the second and tack both the second and third in place. None of my joints are kinked.

The difficulty is having the long 3-footers waving around and trying to solder them while in place on the layout. But it can be done. I was a spanking tyro at soldering, and I did it. Key is to find a way to straighten the pieces while you're soldering them, but remember to anticipate and account for the sliding of the inside rail.

Hope this helps, and good luck.

-Matt

 EDIT: There may be smarter ways to do this, and I'm sure you'll hear of them. I'm a person who cannot think very far down the track, as it were, so I manage each disaster as it befalls me (thereby setting the stage for the next one). There's always a way.

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by Pruitt on Tuesday, November 16, 2021 11:06 PM

Sectional track is easiest, probably, but also the most limiting.

Flextrack is much more "flexible" (sorry), but it takes a bit more work to get a smooth curve. What radius are you building? A larger radius curve is easier to build out of flextrack than a tighter one.

Which brand of flextrack will also impact how easy it is to build a smooth curve.

Assuming HO, Atlas track is probably the easiest to use, since one rail slides easily through the ties. It's pretty easy to build a curve thanks to that feature, as you don't have to be quite as precise with inner rail length cuts as you do with other brands where a rail doesn't slide easily.

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Posted by crossthedog on Tuesday, November 16, 2021 11:26 PM

Pruitt
Which brand of flextrack will also impact how easy it is to build a smooth curve. Assuming HO, Atlas track is probably the easiest to use, since one rail slides easily through the ties.

Good point, Mark. I forgot to mention that I settled on Atlas code 83 flex. The first couple of flex pieces I bought (just to get my old engines out and have something to test stuff on) were some other brand, very stiff, and not friendly to work with at all. I have cast those aside. The Atlas track is very easy to work with.

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by Lastspikemike on Wednesday, November 17, 2021 8:20 AM

Atlas conveniently makes 24" radius sectional track so I don't bend flex track down to that radius I just buy a pack of curves. Connecting the curved sectional track to flex track at each end of the curve allows easy easement from curve to straight so I use flex track for straights and larger radius curves.

A rail joiner won't slide through the spike heads. Atlas also makes handy flex track end pieces of four ties cast with the joiner recess for easy connection of rail ends.

If you want soldered joiners it gets tricky to fit the inside rail without cutting spike heads off and creating gauge issues. I don't bother to solder rail joints. Any continuity issues can be resolved by adding more power feeders instead.  

It seems to me to be feasible to solder just the outside rail joiners initially, then form the curve, trimming the inside rails to fit as you go and only fitting joiners and soldering them to inside rail joints after the desired curve is achieved.   I've successfully curved several connected pieces of Atlas flex track with the joiners in place but not soldered on the outside rails but not on the inside rails. 

The issue is creating a constant radius right out to the ends of the flex track forming the curve. The ends of the curve benefit from the sort of automatic easing you get bending flex track but it hinders forming a smooth constant radius curve between easing at the ends. 

Peco is more flexible and easier to bend closer to the ends of the flex track but it is also a lot less robust than Atlas.

So far I find the new Walthers line the easiest to use to form smooth curves. Their flex track bends more easily than Atlas but has more robust spike heads than Peco.

Model Engineering flex track is just floppy  and so are the ends of their turnouts. ME flex track requires a different approach to get a smooth curve but when it works it works well. 

Alyth Yard

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Posted by wjstix on Wednesday, November 17, 2021 9:10 AM

Right now it can be hard to find, but Ribbonrail - the people who make the curved and straight track laying gauges - make pre-cut curved and straight roadbed made of Upson board. You would lay that down instead of cork roadbed, and then you just need to keep the flextrack in the center as you lay it down.

If you do use it, you need to either paint the upson board pieces completely, or spray them with something like Testor's Dullcote. Otherwise, they can 'flex' a bit with weather / humidity changes.

Stix
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Posted by doctorwayne on Wednesday, November 17, 2021 11:41 AM

Rather than soldering a bunch of flex track together, I found it easier to put down one piece at a time, then trim the rails as required, before adding the next piece.  It never occurred to me to keep the sliding rail on any particular side.

I have used Central Valley tie strips on some of the track on the partial upper level of my layout, and except for turnouts (all drop-ins from various manufacturers), there's about 40' of mostly double track (in other words 80').  I found that it was fairly easy to solder 4 or 5 pieces of rail together, then install it on the tie strips using contact cement.  Lengths longer than that were difficult to handle.

All of my layout's track is soldered together, with insulated gaps where necessary, for isolating certain areas on my DC-only layout. 
Two wires provide power to all of the track.  One of these days, I should make up a train of a suitable length (10' or 20'?), and measure exactly how much track is there.  I know that it's several hundred feet, but the actual measurement would take some time to complete.  Since I run only one train at a time (usually with multiple locomotives), there's no particular strain on the power supply. 
It's easily handled a dozen locos at a time, in a game I sometimes play with my grandkids.

All I can say is that the trains run just fine.

Wayne

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Posted by crossthedog on Wednesday, November 17, 2021 11:59 AM

doctorwayne
Rather than soldering a bunch of flex track together, I found it easier to put down one piece at a time, then trim the rails as required, before adding the next piece.

Wayne, I imagine this would work fine with very large radius curves. My space is tight and my minimum curves are 24", and I found that curving flex track to that degree and then trying to solder them together creates a kinky joint (I'm imagining a less-than-reputable trackside business at the dodgy end of town called Mazy's Kinky Joint -- maybe Walt's Cornerstone should get working on that). But maybe the OP should try it first as you suggest, especially if he has wide curves. It would be a lot less trouble.

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by Water Level Route on Wednesday, November 17, 2021 12:19 PM

crossthedog
I imagine this would work fine with very large radius curves. My space is tight and my minimum curves are 24"

Still easily done with 24" (even 22", probably tighter).  Lay most of the piece, leaving the last few inches to lay straight.  Solder your next piece to the little bit left straight (as a straight connection, but trimming rail as necessary for the curve) and continue laying your curve.  I've done it plenty of times building down to 22" radius turns using this technique.  Never tried tighter but I don't see why it wouldn't work.

Mike

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Posted by crossthedog on Wednesday, November 17, 2021 12:49 PM

crossthedog
There may be smarter ways to do this, and I'm sure you'll hear of them.

Water Level Route
Still easily done with 24" (even 22", probably tighter). Lay most of the piece, leaving the last few inches to lay straight. Solder your next piece to the little bit left straight (as a straight connection, but trimming rail as necessary for the curve) and continue laying your curve. I've done it plenty of times building down to 22" radius turns using this technique. Never tried tighter but I don't see why it wouldn't work.

Q.E.D. Beer

 

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by doctorwayne on Wednesday, November 17, 2021 1:28 PM

I should have mentioned it, but Mike's reply has it covered:  the last few inches of the track that's in place should be trimmed as needed, then the next piece soldered-on, and the tracklaying can continue. 

Once it's all in place, you can go back with some modified ties to take care of the gaps between sections.

Wayne

 

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Posted by azrail on Wednesday, November 17, 2021 1:44 PM

You can't do transitional curves-which are a necessity for smooth curves-with sectional track.

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Posted by selector on Wednesday, November 17, 2021 2:24 PM

doug57

What would be the best way to lay curved track? Purchsae the required radius pieces, or solder three sections of flex track together.

Doug

 

Doug, 'easy' has different connotations in the hobby.  Like the old saw saying you can have it cheaply, quickly, and good quality, but only two of those qualities at the same time.

If you don't mind the expense of the sectional track, and the look/code, I would call that easy. Means more joints, more joiners if you have to supply them, and you're limited to the radii closest to what you need.

Flex gets you closer to what you need, but allows so much more range over and above what your plan intends for the curve we're discussing.

Both require some kind of a centerline, at least in concept, but many of us actually draw one.  If it's of a common sectional radius, yup, that's really easy.

If your radius is 26.3", flex is going to do the trick.  

You can lay flex curves several ways.  I find I like to lay one length at a time, and then fiddle with the sliding rail and tie removal where the sliding rail finally abuts up to the same rail in the piece already in place.  It takes maybe five minutes of filing, trimming, sliding back and forth, getting the joint just right, driving in a few push pins or small black track nails to keep it all aligned until I solder the joints and ballast the tracks.

IF you enjoy the looks of eased curve ends, and superelevation, you'll have a much easier time of it with the flex.  Sectional tracks don't superelevate quite as well, but it can be done.  You can't ease sectional curves unless you add a wider radius piece at each end of the curve.

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Posted by Lastspikemike on Wednesday, November 17, 2021 2:34 PM

Laying Atlas or Walthers flex track with the sliding rail on the inside of the curve uses slightly less total track because you only need to cut the end off one rail.

Fitting the sliding rail to the outside of the curve also spaces the ties a bit further apart.

Theres no technical reason to fit the sliding rail on the inside or the outside of a curve or an s bend wouldn't work if formed in one piece of flex and it does.

Peco track has both rails sliding to some degree, I'm never sure if it's an identical resistance to sliding for each rail or slightly different. It can be a nuisance or an advantage depending on what you're trying to do.

ME is equally curvable left or right as both rails can slide and the rail/tie combination they use curves really easily. Some find it is too easy, I'm one of them. But for some applications ME works particularly well. 

Each brand has advantages and disadvantages. If you are laying 24" or tighter radius then sectional track has significant advantages over flex as long as you don't want easements (Kato has none) or you are prepared to create easements by using flex track for adjoining straights and fit a suitably progressive curve into the end of the straight instead.

Alyth Yard

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Posted by York1 on Wednesday, November 17, 2021 3:30 PM

doug57
What would be the best way to lay curved track? Purchsae the required radius pieces, or solder three sections of flex track together. Doug

 

Doug, reading all the replies, it might sound like laying flex track is very difficult.

I had never laid track before my present layout.  I used only flex track.  There were a few trial and error mistakes, but it was actually pretty easy.

I soldered the track joiners on curves after having a joint kink a little without soldering.

I would recommend using flex track.

My kids say they want a cat for Christmas.  Normally I do a turkey but hey, if it'll make 'em happy ...

York1 John       

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Posted by BigDaddy on Wednesday, November 17, 2021 6:03 PM

York1
Doug, reading all the replies, it might sound like laying flex track is very difficult.

And it's not difficult.  I have never had to "remove half the ties"  Because it doesn' have that funny H piece at the end of sectional track, it looks better too.

Henry

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Posted by ricktrains4824 on Thursday, November 18, 2021 5:27 PM

I can vouch that ME is different from Atlas, but if you know the "tricks" it is very easy to get a smooth curve. 

Requires a paint stir stick. You start to curve it by hand, then drag the paint stir stick back and forth on the tie ends on the inside of the curve with slight outward pressure. 

Get to the approximate radii needed, then lay into place and make final adjustments as you tack it down. As it tends to hold a shape better than Atlas, I can get smoother curves with ME than I can with Atlas. Soldering is easier, as the rails are not as springy, so once curved properly, they will sit nicely to solder together.

Never tried Peco, nor the new Walthers.

Ricky W.

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Posted by Doughless on Friday, November 19, 2021 8:36 AM

Is OP trying to form an easement into a 24 inch radius curve?  Its already too sharp to look like a prototypical curve, so why fuss with an easement?

Just use sectional track for curves 24 inch radius and less.

You can do it, but flex track really wasn't designed to replace curves that could be made with sectional track....especially 24 inch radius curves.  It was designed to provide that realistic sweeping non-straight long curve that is impossible to build by combining sectional straights and curved tracks.

Compare the tie spacing appearance of curved sectional track and sharply curved flex track and you'll see that flex track really wasn't designed to do what OP proposes.

- Douglas

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Posted by mbinsewi on Friday, November 19, 2021 8:54 AM

I've "stretched out" sectional curve track, by cutting the plastic, under the rails, between the ties, on one side, to help with easments and alignments.

Mike.

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Posted by Lastspikemike on Friday, November 19, 2021 9:06 AM

mbinsewi

I've "stretched out" sectional curve track, by cutting the plastic, under the rails, between the ties, on one side, to help with easments and alignments.

Mike.

 

I have done this also. It works. The plastic tie moulding seems stiffer than that used in flex track but that may be illusory.

Alyth Yard

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Posted by dknelson on Friday, November 19, 2021 12:05 PM

My curves are fixed radius (fairly generous, minimum radius is 38") with transition/easement curves on the ends where they meeting tangent.  I use a trammel with a pencil to mark the fixed radius curves on the plywood or homasote subroadbed before I cut it from the sheet.  Then I use templates I made out of sheet styrene that show the 2" spacing I use -- one template is 42" and 40" radius, the other is 40" and 38" readius - to verify the center lines that the pencil in the trammel made.  I have a similar template for tangents

The reason for this is that by laying the cork roadbed following the penciled center lines, I avoid - or try to -- the little bit of cheating that is so easy to do when laying track, even using RibbonRail curved jigs between the rails.  It is easy and tempting to squeeze a curve here or there even with sectional track.  Assuming I do it all correctly the curves are smooth and even.

Dave Nelson

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Posted by jjdamnit on Friday, November 19, 2021 2:16 PM

Hello All,

azrail
You can't do transitional curves-which are a necessity for smooth curves-with sectional track.

I respectfully disagree.

On my pike I use sectional track with 15-, 18- and 22-inch radii.

Some curves are asymmetrical- -half of the curve is composed of 15-inch and the other half is 18-inch radii with a 2-inch section of straight track easement between them.

Other curves are half 18-inch and half 22-inch radii with 3-inch easements between the curves.

A curved turnout also has a 2-inch easement entering it, with a 4-inch easement to a #6 turnout on the "outside" radius.

I have also made DIY flex track.

Several articles in MR magazine have been written about modifying turnouts to fit a particular situation.

Yes, sectional track can have transitional curves, even within the same piece of track by utilizing the methods outlined in my DIY flex track post.

All it takes is a few simple tools: track rail nippers (flush cut), a razor saw, and sharp blades in a utility knife or #11 hobby knife.

As far as which is "better"...

Well, I'll leave that decision up to the individual.

Hope this helps.

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

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