Hello everyone. I have a helix with a radius 22"/24". The whole thing is about 4.5 turns, which is about 58 feet of track. The Alan Gartner’s site indicates a single DCC block should not be more than 30 feet. As such, I’m wondering if I need to break my helix into two halves. The problem is the helix is completely circular, and cutting the flextrack is sure to be disastrous. So my question is two fold: first, should I worry about the 30 foot limit? If so, any suggestions on cutting the helix track without completely ruining the train’s ability to navigate the helix? Any suggestions welcomed. Thanks.
I have very little knowledge of DCC… but couldnt you just insulate the rails on the top section from the bottom section with a plastic joiner and then feed each “half” seperately?
Tom, the recomendation about 30’ refers to the Bus not the total length of the track. The bus itself should not be more than 30’ away from the booster itself at its farthest point. I would add feeders to each loop of the helix. You would have a feeder every 13 foot of track but the feeder runs from the bus would only be a few inches. If you brought the bus to a terminal strip located at about 2 3/4 turns into the helix, you could then just bring feeders from it to each of the turns in the helix with no problem at all. This is not in a helix (it is in a yard) but shows the technique:
The main bus is the #12 black and white wires and the feeders to each track are the #22 black and red wires.
With DCC a bus / feeder system suitable for 58 feet of length length would apply - such as 12 gauge and 20 gauge. Feeders to EACH segment of track (yes each!) would give you peace of mind ONCE rate of climb and vertical easments (top & bottom) have been established, I see no reason it can’t be all one block. One enters - and exits. Multiple blocks need extra wiring , plus ‘eyeballing’ to prevent crashes. Our club used fixed TV cameras and TV screens plus reqires sombody available to man each Helix. Next consider ACCESS. Should something stall, or worse derail, you need to get at it. Bullet proof trackwork is necessary, and Atlas re-rerailers top & bottom are a good idea. You might also consider narrow strips of clear plastic stapled onto the sides to prevent prized equipment taking a shortcut to the floor. As for cutting flextrack - wiring flextrack - on a helix, one works from the bottom up, and the rules for cutting track on a curve apply - excenpt for not soldering each joint. Doing that could bring on expansion problems.
Hi Tom, There are many ways to do the same thing and here is mine. I made a jig out of lauan plyboard, using the factory straight edge for the straight slot of this jig. After sodering the track, its straight both horz and vertical. If a tie melts it cant curl up and be a problem, use a hot tip with a tad of soder on it, if it aint smooking before you put the tip on the rail its too cool, Key is to very quickley get in, soder, and get out.Cutting flex track is a piece of cake as well as sodering the track (dont inhale the fumes)
Nail track a foot or so from end of track, slip jig under track, add another track, mark, cut, and soder.Check for soder burs on track, check gauge and run trains on each level befor going to next loop. I have never had a derailment using this jig and thourly inspecting rail joints befor each loop.
I dont nail helix track in solid, set nails so the track is just held in a curve, no more as the track will expand to the side with no problems, its not going anywhere as its solid, top to bottom.
The helix can be one DCC block - just make sure you have multiple feeders spaced along the helix. Our club has a 5 turn helix on 33"/36" radius track. There are feeders on each section of flex track so that there minimum voltage loss. My own home layout has 25’+ power bus’s out to the actual trackage ‘power districts’ and I have had no problems. I have a #22 feeder from each piece of track down to a #18 power bus. The power bus’s are fed by a Digitrax PM42, and this is tied back to a pair of Digitrax boosters. If I did it again, I would use #10 residential wire for the power bus’s…
What I would be most concerned about is:
The very tight radius curves you have in the helix(what grade do you have?). Pulling/controlling trains may be a real issue.
22"/24" parallel trackage may cause ‘sideswipe’ issues with longer cars/engines. With 4 axle GP’s and 40’/50’ freight cars there may be no problem.
Thanks everyone for the responses. I think I’m good with my current setup. I have two bus lines feeding the helix, one from the bottom and one from the top. The buses are each about 30 feet. I have feeders on nearly every track (which is standard practice on my layout). I’ll have the entire helix on a separate block (well, probably two, one for each track). I’ll post pictures when I get a chance.
I’ll be interested to see how this turns out for you. I’m just finishing up a staging yard and will be building my own helix in a month or so. Strangely enough, it has the same number of turns as yours, and my radii are 22" and 24.5". It’s a single track helix, and my grade is planned at 2.5%. Here’s a switch . . . I’m building my whole layout out of foam, including the helix. 1/2" foam in the helix so there’s sufficient clearance between levels. A couple of people in my NMRA division have built such structures and they work well, so I have some people to consult. But it’s a first for me!
jrberneir: Please excuse a “sidebar”. I’m still strictly DC & even there #18 is a bit light for power bus. With a single power bus, the current can come from only one “direction” to the #22 feeders. An easy fix is to add a second #18 wire to the present bus – tie the ends of the second bus to the ends of the first & don’t worry about the feeders inbetween. This creates a “same-potential” loop on that power feeder and the current can then reach the #22 feeders from TWO directions!!! Works great in DC, should work OK in DCC & I’ll leave a better “explain” to some EE.
Should you wanna go to the #10 bus, there’s no need to rip out the #18 bus, assuming you made a good mechanical connection at each of the #22 feeders. Leave the #18 alone – string the new #10 along side & strip the insulation at each feeder. Wrap the #10, the#18 & the #22 with a couple turns of #22 and solder the whole thing. Yes, this will take a little time, but much less than if you try to remove the #18. And then you’ll have a #10 feeding each #22 feeder. Good Luck !!!
I was just engaging in the danerous sport of thinking, and I realized that I think someone was talking about having bus lines run up and down the helix following the track. No need for that, just run up the inside. If you want to have more that one set of feeders per loop, have two runs up the inside.
