Re: Wiring a Helix for DCC

Vollrath, Don <don.vollrath@...>

Brian, An ideal connection is to have a track bus feeder about every 6 ft. What I might recommend is …

Run a sub-bus up/down along one of the uprights. 14-16 AWG

Add track feeders to the sub bus at each circular pass of the spiral.

Solder the track joints in the spiral for alignment and continuity.

Leave plenty of space gaps in the rails at top and bottom for expansion/contraction.

But with an approx. 33 inch outside radius, the rail length on each turn will be ~17 ft long…. Or about 8+ feet from the nearest outside upright and track feeder. There is no need to follow the track along the spiral with an electrical wire, but if you are overly concerned, providing a second sub-bus and connecting to each set of rails at each pass on an opposite upright will double the electrical connections and reduce the electrical path to the nearest feeder to be less than 5 ft. A little on the side of overkill.

DonV

From: w4dccqa@groups.io [mailto:w4dccqa@groups.io] On Behalf Of Brian Eiland
Sent: Thursday, June 07, 2018 1:10 PM
To: w4dccqa@groups.io
Subject: [w4dccqa] Wiring a Helix for DCC

I've seen a few references that suggest it is NOT necessary to run the bus-lines along the track route in a spiral helix, but rather just run the track feeders lines down one of the vertical legs (post) to the bus wires at the bottom. I thought this was a good idea.

My question is how many of these vertical connections should be made?

My helix is a double track affair with radii of 32.5” and 29.5”. I have plans to stagger the rail joints, and to solder all the rail joints,...code 100 Atlas rail.

Considering this sort of relatively small radius/circumference, I'm thinking I need only one feeder set of wires for each elevation/loop of the helix. And perhaps these feeders wires might be sized a bit larger than normal??

Re: Wiring a Helix for DCC

John Cahill

I have a similar helix and use threaded rod but never thought to use them as a bus. Interesting concept. I did stagger joints as it helped keep kinks out of the rails. I fed the busses up round the rods inside and outside for the two lines and wound them round the rods taking feeders off to each yard of track (don’t like soldering fishplates to track). Solder as usual to convenient spot on the rails. Hope this helps.

Best Regards,
John

Re: Older Shinohara Turnouts

George Galyon

Our club has two Shinohara turnout assemblies (a 3-way and a double x-over) with the "old" double cross-bar design.  Both work well in DCC and DC with just point-to-stock rail contacts...no derailments..nada.
Try it ..you'll like it. I think the saving grace is that these turnouts have a generous "gap" between the point rails and the stock rails ...generous enough so that none of our rolling stock bridges the point-to-stock
rail gap.  And..we keep the point and stock rail contact area clean with an occasional swipe.

Note:  I did jumper wire the point-to-closure rails on the 3-way for better electrical continuity..no gapping though.

Note:  I did "putty up" the X-crossings on the double crossover to eliminate shorting.  You need to cover the vertical surfaces at the crossing for good DCC operation.  With India ink I needed to put an auto light bulb in one (of the two) feeder wire.  With JB weld I got enough thickness on the vertical surfaces of the X-crossing so I didn't need the light bulbs.
ref.  See Double-crossover article on "Wiring for DCC" web site.

Hello

John Gondek

I am responding to the e-mail. I am a new to dcc starting my first layout at 67, better late than nevre.

John

Re: Wiring a Helix for DCC

Brian Eiland

This subject of track expansion comes up again and again. I even started a separate subject thread on this subject, and it does appear to be a roadbed issue rather than the track itself

What exactly is the problem that almost all us face with our model railroad track seeming to change shape (length in particular), with temp & humidity variations? Can it be attributed to the track alone, or the subroadbed alone?  ...or primarily to __?

I've heard a number of folks who say the expansion/contraction of our rail itself is minuscule compared to that of the wood that most of our subroadbeds are constructed of.?... And that is the primary reason we experience what appears to be a change in track length, but its really the roadbed the track is attached to??

On Thu, Jun 7, 2018 at 3:27 PM, John Cahill wrote:
I have a similar helix and use threaded rod but never thought to use them as a bus. Interesting concept. I did stagger joints as it helped keep kinks out of the rails. I fed the busses up round the rods inside and outside for the two lines and wound them round the rods taking feeders off to each yard of track (don’t like soldering fishplates to track). Solder as usual to convenient spot on the rails. Hope this helps.

Best Regards,
John

Re: Wiring a Helix for DCC

Don Vollrath

Yes Brian. It is the roadbed that contracts and expands far more so than the metal rail. When the roadbed shrinks and there is no place like a gap at rail joints for the rail to slide into it can force a kink to occur. If you have neatly nailed down flextrack in multiple places the rials will kink and make wave-like curves between the nails. So in a multi-turn helix one might be better off soldering all rail joints but only securing the track with one nail per helix turn. Now you will not notice the change in roadbed dimension as the track, ties and all, will move ever so slightly.

DonV

Re: Wiring a Helix for DCC

Mark Cartwright

My Helix is similar to yours; but in a double N Scale Double Kato Unitrack at 30' and 28" radius in a oblong shape at a 1.5% Grade. For now the straights carry all of the grade and the Helix flattens out into the curves. The overall dimensions of this N Scale Helix is 63 x 96 inches. (about the size of a Queen Sized Bed.
===
Each level is constructed on four modules, which are held up by all threads. Each module is 1 1/2 inches thick with 5 mm triply facing on both sides. Squared to the outside but rounded to the inside, like a football/track field; as found at a High School.
===
As for my bus lines...
Kato Drop down leads every 90 degree Quarter Radius approximately every 36 inches. And one drop down lead per straight module.
That is six drop down leads per level.
> Yes, I solder each section as well. Being very careful to set each section flat with top rail to top rail leveling. I clamp each two sections to  either marble or steel strip as I solder, then go over the finished/soldered rail with a variety of files, both on top and the insides.
These plug into Kato Blue Boxes which have been opened up and 12 gauge color coded wire soldered through them.
====
I have only tested this arrangement and do not have it currently in an operational layout.
The Kato Track was to be set upon CCW-705 underlayment which quiets it up substantially on a sub-strand level.
For now I do not totally solder my track. Instead, i put a toothpick slice of Dielectric Grease between each snap section; as I test.
====
This Helix was to be part of a three tier multi-connected layout in a large basement....but I have moved, my sleeping arrangements to a another location which also sports room for a layout.  So My Helix basically sits in the basement as storage for now.
====
Sounds to me you have a good clue on what to do already.
Mark

Re: Wiring a Helix for DCC

Brian Eiland

One nail per helix turn sounds like far to little in a helix spiral? Did you perhaps mean one nail per 36" section of track?? .....Even that sounds questionable.
Brian
*************************************

On Thu, Jun 7, 2018 at 10:17 PM, Don Vollrath wrote:
Yes Brian. It is the roadbed that contracts and expands far more so than the metal rail. When the roadbed shrinks and there is no place like a gap at rail joints for the rail to slide into it can force a kink to occur. If you have neatly nailed down flextrack in multiple places the rials will kink and make wave-like curves between the nails. So in a multi-turn helix one might be better off soldering all rail joints but only securing the track with one nail per helix turn. Now you will not notice the change in roadbed dimension as the track, ties and all, will move ever so slightly.

DonV

Re: Wiring a Helix for DCC

Timothy Holmes

Im listening to this discussion closely, as I am about to begin construction of a helix

TIM

On Fri, Jun 8, 2018 at 7:57 AM Brian Eiland <railandsail@...> wrote:
One nail per helix turn sounds like far to little in a helix spiral? Did you perhaps mean one nail per 36" section of track?? .....Even that sounds questionable.
Brian
*************************************

On Thu, Jun 7, 2018 at 10:17 PM, Don Vollrath wrote:
Yes Brian. It is the roadbed that contracts and expands far more so than the metal rail. When the roadbed shrinks and there is no place like a gap at rail joints for the rail to slide into it can force a kink to occur. If you have neatly nailed down flextrack in multiple places the rials will kink and make wave-like curves between the nails. So in a multi-turn helix one might be better off soldering all rail joints but only securing the track with one nail per helix turn. Now you will not notice the change in roadbed dimension as the track, ties and all, will move ever so slightly.

DonV

--

Tim

San Luis and Rio Grande

Re: Wiring a Helix for DCC

Dale Gloer

For what it's worth, on my previous layout I had a 4 turn, 2 track helix in HO with a 27 inch radius.  Each turn was split into 2 parts with detection on each part.  I ran the track feeders down the the track bed supports to terminal blocks that connected to current detectors.  This arrangement was absolutely trouble free.  I used 18 gauge wire for all the track feeders from the terminal blocks.  Don't skimp on wire size.

Dale Gloer

Re: Wiring a Helix for DCC

John Cahill

I see where Don is coming from and how that would work. I used plywood and it doesn’t move noticeably even with significant temperature changes.

Best Regards,
John

On 8 Jun 2018, at 13:28, Timothy Holmes <taholmes160@...> wrote:

Im listening to this discussion closely, as I am about to begin construction of a helix

TIM

On Fri, Jun 8, 2018 at 7:57 AM Brian Eiland <railandsail@...> wrote:
One nail per helix turn sounds like far to little in a helix spiral? Did you perhaps mean one nail per 36" section of track?? .....Even that sounds questionable.
Brian
*************************************

On Thu, Jun 7, 2018 at 10:17 PM, Don Vollrath wrote:
Yes Brian. It is the roadbed that contracts and expands far more so than the metal rail. When the roadbed shrinks and there is no place like a gap at rail joints for the rail to slide into it can force a kink to occur. If you have neatly nailed down flextrack in multiple places the rials will kink and make wave-like curves between the nails. So in a multi-turn helix one might be better off soldering all rail joints but only securing the track with one nail per helix turn. Now you will not notice the change in roadbed dimension as the track, ties and all, will move ever so slightly.

DonV

--

Tim

San Luis and Rio Grande

Re: Wiring a Helix for DCC

Vollrath, Don <don.vollrath@...>

A good alternate is to use typical slip-joint type rail joiners with a slight gap in the rails to allow for track-bed movement. Firmly anchor the ties on both sides of each rail joint to help prevent any kinking. Then add an electrical feeder to every section of rail not soldered to another rail with an electrical feeder to the power sub-bus to ensure there will never be any discontinuity.

DonV

From: w4dccqa@groups.io [mailto:w4dccqa@groups.io] On Behalf Of John Cahill
Sent: Friday, June 08, 2018 8:33 AM
To: w4dccqa@groups.io
Subject: Re: [w4dccqa] Wiring a Helix for DCC

I see where Don is coming from and how that would work. I used plywood and it doesn’t move noticeably even with significant temperature changes.

Best Regards,

John

On 8 Jun 2018, at 13:28, Timothy Holmes <taholmes160@...> wrote:

Im listening to this discussion closely, as I am about to begin construction of a helix

TIM

On Fri, Jun 8, 2018 at 7:57 AM Brian Eiland <railandsail@...> wrote:

One nail per helix turn sounds like far to little in a helix spiral? Did you perhaps mean one nail per 36" section of track?? .....Even that sounds questionable.

Brian

*************************************

On Thu, Jun 7, 2018 at 10:17 PM, Don Vollrath <donevol43@...> wrote:

Yes Brian. It is the roadbed that contracts and expands far more so than the metal rail. When the roadbed shrinks and there is no place like a gap at rail joints for the rail to slide into it can force a kink to occur. If you have neatly nailed down flextrack in multiple places the rials will kink and make wave-like curves between the nails. So in a multi-turn helix one might be better off soldering all rail joints but only securing the track with one nail per helix turn. Now you will not notice the change in roadbed dimension as the track, ties and all, will move ever so slightly.

DonV

--

Tim

San Luis and Rio Grande

Re: Wiring a Helix for DCC

Stephen Lamb

This is how I constructed my helix:-

The Bus is clipped to the inner edge of each 9.5mm thk board which are cut out in 120deg arcs using a template which also positition holes for the M12 screwed rod stantions. Each length of rail has a soldered tail running from the bus and completed as each level is added.

Re: Hello

Tim Bowser

Required post to verify I'm not a spamming troll.  :-)

I'm returning to the hobby after a 20-year gap, continuing the march away from DC block control, to Bob Keller's "Onboard" pre-DCC walkaround cab, and now the NCE ProCab (PH-Pro-R) DCC system.  I managed to get a simple Free-Mo module wired almost properly (neglected to spiral wind the track bus to fend off signal corruption), and from reading here and Mark Gurries' posts, need to gap a test oval's rails for pretty much the same reasons.

This DCC, it isn't your grandpa's power packs.

Tim B.

Re: Wiring a Helix for DCC

Dale Gloer

John,  the expansion/contraction issue with any kind of wood is mostly related to the humidity of the environment, not so much on temperature.  Plywood should move a lot less than dimension lumber but is not immune to it.  I live in a semi-desert climate with large differences between summer and winter temperatures and therefore large swings in humidity.  My benchwork is all plywood and I still get issues with seasonal expansion and contraction.

Dale Gloer

Re: Wiring a Helix for DCC

Stephen Lamb

I sealed all surfaces and edges of the plywood segments with a 50/50 water/PVA mix.and have not experienced any problems with expansion or contraction although the monitored humidity fluctuates between 45% and 84% with temperatures between +5degC and 24degC. The shed  has automatic frost protection that kicks in at +5degC. The inner walls are lined with plywood to inhibit condensation and are constructed with vapour barrier membrane/50mm polystyrene insulation and 50mm air gap as so are the walls and ceiling. There are adjustable slots in the ceiling to provide ventilation.

Helix

Jerry Kramer

Information is helpful but duplicates what I have. Just trying to get it built period. I have a birth disability that prevents me from assembling.

Sent from XFINITY Connect Application

Re: Wiring a Helix for DCC

Charles Brumbelow

Has anyone experimented with sealing the roadbed to reduce expansion and contraction? Shellac might be satisfactory and inexpensive.

Charles

Re: Wiring a Helix for DCC

John Cahill

Guess my next layout will be plywood painted with diluted PVA to seal it! We don’t get extremes in temperature but humidity can go from very dry temperate climate to cold wet, and change can be fast.

Best Regards,
John

On 9 Jun 2018, at 16:15, Dale Gloer <dale.gloer@...> wrote:

John,  the expansion/contraction issue with any kind of wood is mostly related to the humidity of the environment, not so much on temperature.  Plywood should move a lot less than dimension lumber but is not immune to it.  I live in a semi-desert climate with large differences between summer and winter temperatures and therefore large swings in humidity.  My benchwork is all plywood and I still get issues with seasonal expansion and contraction.

Dale Gloer

Re: Wiring a Helix for DCC

Brian Eiland

PVA,....basically wood glues we use so often?

I also found this...
http://www.instructables.com/topics/What-is-the-difference-between-PVA-glue-and-Elmers/

On Sat, Jun 9, 2018 at 6:48 PM, John Cahill wrote:
Guess my next layout will be plywood painted with diluted PVA to seal it! We don’t get extremes in temperature but humidity can go from very dry temperate climate to cold wet, and change can be fast.

Best Regards,
John

On 9 Jun 2018, at 16:15, Dale Gloer <dale.gloer@...> wrote:

John,  the expansion/contraction issue with any kind of wood is mostly related to the humidity of the environment, not so much on temperature.  Plywood should move a lot less than dimension lumber but is not immune to it.  I live in a semi-desert climate with large differences between summer and winter temperatures and therefore large swings in humidity.  My benchwork is all plywood and I still get issues with seasonal expansion and contraction.

Dale Gloer