I am changing a few turns in my layout to accommodate longer passenger cars. I am easing a few turns radius up to 30”. I will be using flextrack for the turns and looking for a template, tool or method to use in aligning the track in the turns to as close to and consistent to 30” radius. I noticed that JMD Plastics sells a Curve Track Laying Tool – 3 piece 30” radius. This looks very helpful in closely aligning to a 30” radius. In another turn in the past I have used the pencil at the end of a 30” length of string method to draw the arc, then align the track to the pencil line. The stretch in the string and no template seems to result in a turn with variations in the radius. With the template like this one from JMD Plastics, it looks like the template sits within the flextrack section while you tack the track down. Seems this will result in much more consistent and accurate 30” radius through the turn. So I am thinking I will buy this template to use in revising my layout turns. Wondering if anyone has used this JMD Plastics template? does this work? insure the track aligns to 30” radius? Or are there other tools / templates that work better? Also, in a previous track laying step, I have soldered together two pieces of flextrack to make a turn. In this turn I am making a half-circle – so wondering if it will work to solder together 3-4 pieces of flextrack – or should I limit the soldered pieces to just two and have one rail-joiner in the middle of the half circle? Before I soldered together the flextrack in one of my turns I had derailment problems due to the abrupt rail joint . So thinking if I solder together several pieces, no rail joints through the entire half-circle turn, no possibility of derailment problems – but not sure how that many pieces of flextrack soldered together will work – any experiences with this? Any recommendations? Thanks,
You can make a trammel if you have some thin scrapwood long enough for 30 inch radius. You need a nail close to one end (drill first so you don't split the end), and then several holes spaced at intervals until you reach the other end wide enough to set a sharpened pencil into the holes so that the tip reaches just past the bottom surface. Tap in the nail where you want your center of circle, and the thin insert the pencil where you want the radius, and swing the item in a wide arc. For easements, have your tangent come about 1 cm/3/8" outside the arc you just drew. You can let the flex track elements run along the tangent at the centerline, and anchor it until about two inches just before you want your flex to start to conform to the easement and true radius. Anchor the central third of the radius where it is true to your dimension, and then allow the flex to meet the tangent on the other side that is also offset about 3/8". There is your eased curve and your desired radius all in one.
You should probably only solder two lengths together, place them such that the one most of the way along your curve is free to swing for the last six inches or so, but tack down the rest so it doesn't budge. Then with the free end, solder another length, this one the third, when they are flat and in line...tangent. When you have a solid join, continue to curve the now longer length...and so on.
Crandell
Crandell, thanks - never dawnded on me to use a rigid piece of thin wood to draw the arc - will solve the string stretch problem, as for the easements - great idea on tacking down the center of the turn then work outward to the start of the turn and mid / end of the turn section and have the track run just outside the radius about 3/8" - what may be obvious to some - never seems to be for me - thanks for these tips.
My trammel started life as one of those $0.69 wooden yardsticks sold by Home Depot. The `hangup' hole will take a golf pencil, and I've drilled the necessary center holes for all the radii I use, just big enough to clear a nail. For 30 inch radius I'd drill 3 center holes, 30" even and 30" plus and minus 14mm. (Atlas ties are 28mm long. if your flex uses a different tie length, adjust accordingly.) The end of the tie lines are more useful than trying to sight a centerline through the track nail holes (which aren't drilled all the way through Code 83 flex)
When I lay curved track I pre-bend my flex - fixed rail, if any, to the outside, please - so it will hold the approximate radius I want. That includes some judicious use of pliers on the last few inches of each rail. I also let the inner rail slide so the joints are not directly across from the joints in the outer rail. Clean up every rail end and file a tiny bevel in the upper inside corner of the railhead. That has proven to be one of the best derailment preventers I know.
A final point. An expert can work accurately a lot faster than most of us. Take the time to make those curves as near perfect as you can. The time spent up front will be paid back with time you WON'T have to spend picking up after derailments.
Chuck (Modeling Central Japan in September, 1964)
For a quick and easy no brainer you may want to look at these. the video shows how versatile they are
http://www.handlaidtrack.com/SweepSticks-for-HO-track-30-quot-radius-p/sw-ho-c-30.htm
ratled
Modeling the Klamath River area in HO on a proto-lanced sub of the SP “The State of Jefferson Line”
I use the Ribbonrail Track Alignment Gauge. It is a 10" long metal gauge that fits between the rails and does a marvelous job of producing consistent curves.
http://www.walthers.com/exec/productinfo/170-1030
I also use Altlas Flex Track which is a lot easier to form into curves than other flex track like Peco that wants to snake instead of curve.
Rich
Alton Junction
Eh... They answered your questions, but the LION just plops his tracks down and really does not concern himself with a static radius number throughout the curve.
It looks good, the trains stay on the tracks, the tracks stay on the table: It is good enough for a LION.
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
I use a cheap beam compass set with a 4 foot, 1/2" diameter dowel. I sometimes need a larger radius than what you can get with a yard stick.
Enjoy
Paul
Fast Tracks also has curve alignment tools, in addition to the ones mentioned. I do have some of the Ribbonrail ones, however with Atlas flex track it's more to prevent me from going under my minimum radius. Atlas flex forms a smooth curve automatically because it's springy.
Since my layout is around the walls and the centerline for any curves are in the aisles, I took a scrap piece of wood and drilled a hole at one end to fit over the stud on my tripod, and then drilled holes big enough for a marker at the other end at various raddi. I can adjust the tripod to exactly the layotu level to draw in smooth curves connecting the straight sides. Since I'm using cork, this is the centerline of the two halves, then I align the track to basically the center line of the cork. Everything is fasted with latex caulk, so after the track is set I can slide the Ribbonrail gauge through it and get it all aligned just right, the Ribbonrail forces the track to move is while the caulk is tacky.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
IRONROOSTER I use a cheap beam compass set with a 4 foot, 1/2" diameter dowel. I sometimes need a larger radius than what you can get with a yard stick. Enjoy Paul
For those with truly humongous curves I can see going to one of those folding carpenter's rules, or even a length of 1-by. However, for anything much over 33 inches in the usual (cluttered) layout space, it might be easier to revert to engineering practice and lay out the curve in degrees, with a 100 (scale) foot straightedge attached to the protractor arm. The result would be a succession of 100 scale foot tangents, which can then be faired with a bent batten.
Imagine the consternation in the editorial office when you submit your track plan and specify 17.5 degree mainline curves...
Chuck (Modeling Central Japan in September, 1964 - where the JNR identified curves in metric radii)
Fast Tracks Sweep Sticks are what I use to both plot my curves as well as accurately lay flextrack on my N scale layout. They can't be beat for accuracy`and they come in a large assortment of radii. It may cost more than the price of a Home Depot yardstick, but having an assortment of sizes on hand is well worth the cost in time savings alone.
Frank
You can also use a light chain. It won't stretch like string does.
Dave
Lackawanna Route of the Phoebe Snow
The other question you asked was about soldering more than 2 pieces of flex track together. I wouldn't recommend it for curves. The rail has to slide in the flex track when you curve it. When you solder 2 pieces together, you have to remove 2 or 3 ties to accommodate to the rail joiners moving as the rail slides. Then you can trim the end of the rail even to add the next piece of flex to the other two. If you fasten more than 2 pieces together, by the time you curve the track, the third piece's rail joiner will move so much that you'll have to cut out 6 or 8 ties. The better idea is to solder the rail carefully and only do 2 pieces at a time.
Just my opinion. Take it for what it's worth.
Lefty
Thanks to all of you for your advice and tips, these will really help, and would not have figured this out without some help.
I believe the solid rib of plastic on the flex track goes on the inside of the curve. Also, with regard to rail joiners within a curve, you might consider not soldering them prior to installing the track. It's just my opinion. Some ties need to be removed, and one of the rails needs to be cut in any event. Slightly staggering the joint locations (rail joiners not right across from one another) will help eliminate the tendency of the flex track to kink at the joints. Using your NMRA gauge (or other gauge) to maintain correct rail spacing, the removed ties can be replaced, keeping everything squared away. On either side of each joint, a slick trick is to use a printed circuit board tie with the rail soldered to it. You can then use the PCB tie as a track feeder. For the other ties that have been removed from the flex track, replacing them with wood ties allows the rail to be spiked in position. Spiking the rail joiners on the side away from the curve center can also help maintain a smooth curve. If you choose to do it this way, the rail should be spiked in position prior to soldering to the PCB ties. The rail joiners do not require soldering with this method, and will "give" a bit, allowing a more circular curve at the joints.
If the two pieces of flex track are soldered together with rail joiners while straight, the joints will make a "bump" , or straight kink within the curve since the soldered rail joiner will not bend (the rails will be straight for the length of the rail joiner). Also, there will be compressive force at the joint on the inside of the curve which tends to both force narrowing of the gauge and the rail to rise at that point.
I highly recommend The Trackwork Handbook by Paul Mallery; I do not know if it is still in print.
Good luck & have fun! Ric
drh
One thing not mentioned when using a trammel. You may not always end up with the centerpoint of your radius falling on solid benchwork or at the same elevation as the track. In this case a temp board of sorts, usually a 1x4 will do, will need to be positioned to locate the center of the arc.
Ribbon rail temps, etc can work fine, however, following the outer tie marks as mentioned seems to do fine. The curved templates do help, esspecially if you use a much stiffer flextrack. These can help reduce the chances of slight kinks as you try to force the track to the curve. Also can stop those slight kinks @ the soldered connectors. Generally just nudging the ties w/ a wood block and pinning w/ "T" pins is all that's needed though.
Sometimes on a tighter radius, usually under 24", it can help to slightly overbend the rail ends before placing/ soldering the railjoiners. The rail ends will always seem to want to be forced outward on that tight turn. At the club, we spike the rail flange rather than use nails. This gives us far better control to minimize the whips or kinks by holding the track where nec.
The very stiff track (especially ME) will lay much better "pre-bent" close to the radius. Lay one section, dry fit the next, nudge/ bend the rail ends if nec and then install and solder the joiner. This method also will allow for less tie removal, as someone had already mentioned.
Just need to remember, as long as the trackwork is in guage and you use proper easments, some wave or other track undulations actually can look better while running as well as just sighting sceniced/ ballasted track. Take a good look @ most real 1:1 trackage.
Modeling B&O- Chessie Bob K. www.ssmrc.org
I fix the problem of the pivot being off the benchwork by using a photo tripod for the pivot.
Phoebe Vet I fix the problem of the pivot being off the benchwork by using a photo tripod for the pivot.
Clever idea, just don't bump one of the legs or force the trammel. Don't know just how strong that tripod is, but would set up rather quickly and also adjust height to track level easily. Guess you just can't be a clutz when doing this. Double checking the arc would always be good.
It's a very good quality Bogen tripod. It is VERY stable.
It worked for a living before I retired.