What is the proper name for those curve radius rulers?

Mark Truelove Mar 23, 2023

  1. Mark Truelove

    Mark Truelove TrainBoard Member

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    They're generally steel, and you use them to properly curve flex track to your goal radius when laying track.

    And, if anyone has a favorite place to find them (if that's allowed), please let me know!

    Thanks all.
     
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  2. Sumner

    Sumner TrainBoard Member

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    What flex track are you using.

    I have a couple tools up on thingiverse.com that you can print out but if you don't have a printer Invertlogic on here shows how to make one. Here is a link to Invertlogic's YouTube channel ( HERE ). Check it out as he has many great videos and has a wonderfully detailed 2' X 4' layout that is exceptional. You can also find the video that inspired making the tool below ( HERE ).

    [​IMG]

    Above is a video showing the compass you can print. More about it and print links ( HERE )...

    [​IMG]

    Above is another tool that is my main go-to tool and one you can make if you don't have a printer also. I use ME flex and love it as it is quick and easy to curve into shape with the above tools and it pretty much holds that shape.

    Here is the link to more info on both tools....

    https://1fatgmc.com/RailRoad/Trackwork/Trackwork-Index.html

    Sumner
     
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  3. cbg

    cbg TrainBoard Member

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    Not as fancy, and maybe not as durable, but you could use the string method to draw the radius needed on a good piece of cardboard and use that.
     
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  4. Mr. Trainiac

    Mr. Trainiac TrainBoard Member

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    I would look up 'track curve template' online. Peco makes plastic ones, and I see a few generic ones on ebay and such. Some of them fit on top of the rails, and some fit in the gauge.

    Fast-Tracks also makes a tool they call a SweepStick. It's their version of a track template that fits between the rails. They are laser-cut wood, and you can connect spacers to make parallel double tracks. I used one of the HO tools for a module, and it works decently well.

    If you want to make easements or spiral transitions, it may be a bit more difficult since the radius of those curves constantly changes. For that, you may just be limited to plotting the curve on the benchwork and then lining the track up, or making a custom jig for the entire curve in one piece.
     
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  5. Hardcoaler

    Hardcoaler TrainBoard Member

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    On previous layouts I drilled holes in a yardstick and used it as a giant compass. Simple and cheap, it worked great.
     
  6. Mark Truelove

    Mark Truelove TrainBoard Member

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    Thanks for all the ideas. It seems "template" or "alignment guide" were the terms I was missing, but now that I found one of them they're popping up all over.

    I actually like the yardstick/compass idea. I want to try working with sub-par curve radiuses with shorter cars and switchers to try to run more on a 2x4 base (since 12" curves take you right to the edge). So having flexibility in creating the curve measurement may actually trump all the other methods!
     
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  7. Point353

    Point353 TrainBoard Member

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    If you are referring to the Tracksetta track laying templates, Walthers distributes them, so you can buy them either direct or from any shop that deals with Walthers.
    They're available for N and HO/OO gauges and you can see the various versions listed here:
    https://www.walthers.com/catalogsearch/result/?q=+Tracksetta
     
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  8. BoxcabE50

    BoxcabE50 HOn30 & N Scales Staff Member TrainBoard Supporter

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    I had one, which was used many times. Perfect curves, with little effort needed.
     
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  9. Sumner

    Sumner TrainBoard Member

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    One problem with my compass and using something else that is flat like a yard stick is the part past the pivot point sticks out and can hit things. Also between the pivot point and the marking point it can also drag on things. Working on a nice flat surface is ideal. I can hold mine up above the urface to some point with the nail as a pivot. You could do something similar with the yard stick but I think both might be longer and more awkward for what you need.

    Using a drawing compass like the one ( HERE ) might actually be a better solution if you are working with a radius under 12 inches and there are larger ones.

    Are you planning on using some of the small radius track out there or flex track?

    Sumner
     
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  10. Mark Truelove

    Mark Truelove TrainBoard Member

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    Flex, so I can try different radii. And yes, I noticed that the fixed-radius templates become moot in this situation, since they're sold in radii that people buy, not infinite variations.
     
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  11. Mark Truelove

    Mark Truelove TrainBoard Member

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    Hey I did it, using the compass method. I'm using Peco Streamline flex track in N scale, haven't gotten may hands on any ME track yet to try it. I keep seeing code 70 being thrown about, though - is that likely to cause me problems? (Code 80 everywhere so far)

    So I realized I have several old wooden yardsticks hanging from the pegboard in the basement, and can't remember the last time I used any of them. So I cut one down to just over my radius, measured it and poked a new hole through it. My new <first curve diameter is 8.5 inches. It calculated out to 8 17/32 but I don't have those markings on here, nor that steady of a hand :) I actually added 1/4" to line up with the outside edge of the track plus 1/2 to accommodate the offset of the hanging hole on the other end of the ruler.

    I was able to use a drywall screw into my pink insulation with only hand-strength applied to secure the pivot point. I used a sharpie through my drilled hole to draw slightly past a half circle, then measured a couple of markings for a straight section coming off the ends and tangenting the curve.

    The curve came out beautifully, and one section of Peco covered the whole thing. I use hot glue (I can hear some people groan) to secure my track after I have all the temporary pinning in place.

    Again I'm curious to try ME here since it holds it's shape, which brings up my next inquiry.

    Despite the very smooth curve I produced, it always "seems" as if the junction to the adjoining straight track will never be perfectly straight because of the springy component of the flex track. i.e. the not-so-complete contact of the rail joiners isn't really enough to offset any tendency the end of that rail might have to be a little off-straight. It looks good, and I've tested it with a couple of cars and a loco, but my brain still persists to annoy me.

    A clarification, and one solution I considered, is to extend the curve further into the straight transition before cutting the track and joining it to the actual straight section. This way any errant forces are dealt with in the shaping of the last inch or two, which is solidly part of the curved rail and not just connected by rail joiners. I'm interested in any thought/tricks others have about this, because I'm sure I'm not the first person to have thought of this IMG_20230326_121809.jpg IMG_20230326_121823.jpg IMG_20230326_121839.jpg IMG_20230326_121943.jpg IMG_20230326_121809.jpg IMG_20230326_121823.jpg IMG_20230326_121839.jpg IMG_20230326_121943.jpg already!
     
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  12. Sumner

    Sumner TrainBoard Member

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    Good work and we all have our preferred ways to do most of this.

    [​IMG]

    I start a curve and glue/caulk it down for part of the curve but leave the end straight. Then I cut it off square as the inside rail gets longer bending the track. Then I join it to another straight piece with joiners and solder them on lightly. Then go back to curving the track to and past the joint and caulking it down.

    [​IMG]

    I put the cork and track down with the products above and copied Joe ( HERE ) as I like how he lays track and pretty much follow his techniques. I like caulk that dries clear myself and it would be easier to move the track if required vs. the hot glue I imagine.

    I wouldn't venture into the ME track unless you make or print or buy one of the tools I mentioned earlier. They make it a snap to form into a curve but without them that isn't the case. I was trying to use only ME code 55 and I make my own turnouts so make them from the same rail. Then during COVID ME 55 was hard to get so bought code 70 and also rail to build 70 turnouts. I'm using it in my hidden staging and any place else that it isn't very visible. I think I have enough code 55 to use in all the visible places. Not sure what availability is on either at this point and not sure about mixing it with other track although I know people do. I'm connecting 55 to 70 when I transition from one to the other.

    Sumner
     
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  13. Mark Truelove

    Mark Truelove TrainBoard Member

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    Yes I see lots of people using that or a similar tool on the ME track but it does make a nice result.

    The reason for the hot glue is 1) I'm just experimenting and it's fast, but 2) the Peco positioned into its curve is like a spring wanting to straighten out again (not as bad as Atlas but still present). I can't pull the pins without locking it down first, which would make the caulking process harder. I just don't want to waste this whole box of Peco so I'm trying different ways to make use of it.
     
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  14. Sumner

    Sumner TrainBoard Member

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    Even though the ME will stay 90% to shape I caulk, pin and don't pull the pins to the next day.

    Sumner
     
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  15. porkypine52

    porkypine52 TrainBoard Member

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    You are not using EASEMENTS are you? Don't just run a straight [tangent ] track into curve. Let the tangent track gradually flow into a curve. This is an old book, but ever word in it still applies TODAY [​IMG]
     
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  16. BigJake

    BigJake TrainBoard Member

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    You can also use two nails/screws/pegs and a loop of string to draw a varying-radius, elliptical curve. These often look more natural and pleasing that a fixed radius curve.

    By varying the length of the string loop and the distance between the two nails, you can vary the minimum and maximum radius in whatever section of the ellipse you want.

    The shortest radii of the ellipse will be the half the string loop's circumference, less the distance between the two nails. The sharp ends of the ellipse will be inline with and beyond the two nails.

    The two nails can be in a yard stick, strip of pegboard, etc. that you can move around the layout, and vary the nails/pegs' locations and orientation (and therefore curve) on the layout.
     
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  17. jhn_plsn

    jhn_plsn TrainBoard Supporter

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    20230220_183608.jpg 20230225_140335.jpg 20230225_140553.jpg 20230225_140802.jpg 20230220_183600.jpg Hey Mark, my solution for joints on curves is to use Gapmasters(four PCB ties connected as one unit) and solder it all together without the rail joiner. Leaving the joiner out lets the rail rest on the Gapmaster and the joint stays flat better. The curved templates sure are nice to have. I ordered the Fastracks version with appropriate separation for clearance. The templates make great solder helpers by holding the rail in a curved state to a point. I noticed when the rail is heated it seems to hold the curve better to. Be sure to use a good flux, tin everything, and have a hot iron. Once the heat hits it all comes together quite neatly.
    Look here for the Gapmasters,

    http://www.americantieandtimber.com/

    I built my helix using this method.
    20230225_140335.jpg 20230225_140553.jpg 20230225_140802.jpg 20230220_183600.jpg
     
    Last edited: Apr 19, 2023
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  18. wvgca

    wvgca TrainBoard Member

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    is the op talking about trammels ??
     
  19. BigJake

    BigJake TrainBoard Member

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    I have a more recent edition of that book, and it is truly a gold mine! It is excellent at explaining various operational moves of a train, and the track features/structures to enable/require them. It also explains various operational schemes that work more efficiently in given circumstances.

    Not mentioned in the book: Easements, of a sort, can also be implemented even in purely sectional track. Just substitute a longer-radius curved section where you transition between straight (tangent) and curved track. You can even compensate for the extra area by using a shorter radius section(s) in the middle of the curve. Most rolling stock has problems transitioning suddenly between vastly different curve radii (including straight track = infinite radius) long before they have problems on a circle of the same constant radius. Think of the ideal curve as being hyperbolic, parabolic, elliptical, or a piece-wise approximation of such.
     

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