hey all ;just finished my oval shaped 3 turn helix ,I left a unsodered jointer on each side (straite sections ) of oval for possible expantion. but not to experianced on this part …would it be better to solder the jointers and cut a gap w/ a dremil tool for releaf or just leave it ? I ask cause I fear the loose joint may get out of line where the cut rail only would still have the uncut tie strip for allinement…? better now than later type of after thought…J.W.
I wouldn’t leave any gaps in a helix, and I would solder all joints. I would expect track kinks due to expansion to happen on tangential, or nearly tangential, track, not on a curve, and not on tracks that are secured with the somewhat pliable caulking.
Crandell
Gaps around curves are NOT recommended.
A lot of people like soldering joints on sections of flex track where there is a curve at the joint. This helps prevent curve “kinks”
Another good way of doing this is use Atlas code 100 track. It’s cheap and provides nail holes to hold down the track at the end. This works well in combination with ordinary bathroom caulk to hold the track in place around curves.
You don’t need to solder joints with (mostly) straight sections.
Experience has taught me that cutting a gap with a dremel is a no-no unless you use metal razor saw blades (which are hard to find). The gap made is just too wide and doesn’t look good. I would use a razor saw if possible.
What are the gaps on the helix for?
Running DC common rail, I cunningly arranged for the common rail to be on the outside of most of my curves. All rail gaps for control are left in the inside rail.
Note, “Left,” not “Cut.” I plan my electricals before I lay track, and put insulated rail joiners where gaps will be needed. That way I can put a little bevel in the railhead to eliminate that hard corner at the joint.
Chuck (Modeling Central Japan in September, 1964)
expantion ,provide abit of relief and protect from kinking …something I read somewhere ,about never soldering more than 3 pcs of flex track to allow alitte expantion gap …now I did use code 100 atlas in the helix as stated above …and hay I can solder those joints faster than typeing this post ,so if concensus is no need for gaps ,so shall it be .I have open access to it right now but when I put the out side wrapper on it (its under a blob) then only access well be up thru middle inside !! thats why IM HAVEING AFTER THOUGHTS…any advise will be helpfull …oh some of the details its HO aprox 29" radius outside loop and 26 1/2" inside loop, double trk, oval shaped to keep @ 2% grade or less (just shy of 6 pcs of flex per track per loop or level)3 level ,12" of total rise …Jerry
I don’t think you need to worry. If you do decide to have gaps, I would not cut them but I would measure and leave them. I would ensure every single rail tip, joined or gapped, has a bevel to help the flanges get past them, and I would probably work at pre-bending the rail tips. On flex, the very last 2" will not bend, or very little, so you need to mechanically force them to retain a real curve. But, at each gapped rail end, I would drive small screws into the road bed so that the heads and shanks abut tight against the rail feet, thus preventing them from shifting out of alignment. In fact, I would probably drive several small screws against the outside rails every 2’ or so just 'cuz. If the rails ever want to deflect on a curve, it will necessarily be towards the outer curve, never inward, because they are already in compression to want to move that way.
Crandell