Large Scale Central

Good Weather activates construction crews

Track and Trestles
#1

BN 2225 inches onto new track as a break in the winter weather allows some work to continue. I guess you could call this my version of the Keddie Wye? Actually we are considering a raised platform in the middle with a station and junction tower.

The Wye connection to the outside world was custom made by Dan from Eaglewings, designed for #6 switches on a ten foot radius. Doug - look no snow under the deck! I still need to get my hands on a bobcat skidsteer to lower the grade on the east end of the line, and will need to get this done before the decomposed granite turns into concrete this summer. John

#2

…grinning…

#3

That’s some serious roadbed under that wye. Looking good!

#4

Well the ground is on a slope. going from about four feet at the house to below grade on one leg and about a foot on the other leg. I looked at all kinds of ideas and decided to have Dan build it.

#5

Yesterday my Train-Li railbender was delivered, once I get it figured out this morning, I will bending track to at least get the Wye working.

#6

The Train-Li railbender works better than I would have ever imagined. I did have to use railclamps on the curves though. Now I gotta take a stab at wiring the reverse loop leg of the wye. BN2225 took a test train out n back.

(http://freightsheds.largescalecentral.com/users/johnm/_forumfiles/Saturdays-progress.jpg)

#7

Looks great John. Reverse loop wiring isn’t too bad, It can be done with diodes or a DPDT switch. You need to isolate one leg with either gaps or insulated joiners. I found this diode method diagram on the net somewhere…

(http://freightsheds.largescalecentral.com/users/jrad/_forumfiles/diodeloop.jpg)

Indoors I use a DPDT switch on a section of reverse loop. Outdoors, my wye is a dead, end, so I simply switch one tail…

(http://lsc.cvsry.com/Wye_Polarity.jpg)

Note that in the above diagram, the optional frog power doesn’t work as drawn. It needs it’s own separate pole (3PDT).

#8

If you use the diode method, just remember that they will have to be beefy enchuritos as the potential current of your supply is ten amps, and that is DC. I foresee heatsinks of a good size.

#9
mike miller said:
If you use the diode method, just remember that they will have to be beefy enchuritos as the potential current of your supply is ten amps, and that is DC. I foresee heatsinks of a good size.
I agree. I haven't tried it yet, but if I did I'd use a large diode bridge with heat-sink salvaged from an old power supply. If you regularly pull close to 10 Amps then the diode method is probably not the best idea.
#10

Thanks, for now I am one of those folks still on track power.

#11

Hey John,

The wye looks great, but all that wiring talk is a big head ache looking for a problem. I know you still use track power but believe me once you go to battery you’ll never look back. You don’t have to worry about wiring, you can run as many trains on one line as space provides and much, much more. Up until about 3 years ago the majority of our club was track power, now its the other way around and it is so much funner. Just my 2 cents.

Chuck

#12

Jon,

Your diodes do nothing but insure that the loco travels the loop clock-wise CW (LS) or counter-clock-wise CCW (NMRA). You still have to time the polarity switching of the mainline power.

If you tie your power pack directly to the (isolated) loop, and have a DPDT switch to flip polarity on the main, you can skip the diodes.

Tie the power pack to a turn around loop on the other end of the main, you should be good to go.

If you get shorted entering a loop, flip the polarity of the power pack feed (i.e., swap the wires) to the loop’s rails, or change your spring loaded turnout points to pull to the opposite side…

Hope this helps.

Sincerely,

Joe Satnik

Edit: Added “swap the wires”.

#13
Chuck Inlow said:
Hey John,

The wye looks great, but all that wiring talk is a big head ache looking for a problem. I know you still use track power but believe me once you go to battery you’ll never look back. You don’t have to worry about wiring, you can run as many trains on one line as space provides and much, much more. Up until about 3 years ago the majority of our club was track power, now its the other way around and it is so much funner. Just my 2 cents.

Chuck


No problem John. I am slowly converting. I have one stand-alone loco and a trail car set ups for 1:20 and 1:29. I’m still wired, but an electron has not flowed through my track in over a year, except to rescue and engine after the battery died :smiley:

EDIT - OOPS - you were addressing the OP. Sorry.

#14
Joe Satnik said:
Jon,

Your diodes do nothing but insure that the loco travels the loop clock-wise CW (LS) or counter-clock-wise CCW (NMRA). You still have to time the polarity switching of the mainline power.

If you tie your power pack directly to the (isolated) loop, and have a DPDT switch to flip polarity on the main, you can skip the diodes.

Tie the power pack to a turn around loop on the other end of the main, you should be good to go.

If you get shorted entering a loop, flip the polarity of the power pack feed (i.e., swap the wires) to the loop’s rails, or change your spring loaded turnout points to pull to the opposite side…

Hope this helps.

Sincerely,

Joe Satnik

Edit: Added “swap the wires”.


Yes. You need to change direction of the power pack. I would stop the train. This is required no matter how you do it - diodes or switches. Even DCC requires some of what Steve F. would call PFM to get through a reverse loop.

Your wiring suggestion for connecting the power pack to the isolated section would certainly work, but might get confusing if you are running multiple trains with block control.

Best solution has already been mentioned - Battery power :smiley:

#15

Hey Jon,

You said - “I’m still wired”

A truer statement was never spoken and that’s something to be proud of. Far better than a short circuit. :wink:

#16

Perhaps some day I will either convert to DCC or Battery. Yes - the reverse leg of the “wye” will have a “red” indication forcing eastbound trains to come to a complete stop before entering the main.

#17

Jon,

Your diodes would change the waveform of a DCC signal (all positive peaks, negative valleys flipped around to positive peaks) and reduce its voltage slightly (2 diode drops ~ 1.4V).

The main under DC power would have to change polarity (no matter what) to have the reversed train travel in the opposite direction.

That main (with one or two reversing loops) would have to be a separate block (electrically isolated) from the rest of your layout if you were trying to run multiple engines off the same power pack.

Hope this helps.

Sincerely,

Joe Satnik

#18

Tonight i cut the wood to make a small panel to control power to the wye and switches (turn-outs in HO speak) So we are moving along.

#19

Jon, tonight I ran the wires to the legs of the Wye… Need to run wires out to the switches… freakin USA #6’s use a four wire. Once that’s done I will wire up the panel.

#20

All the wires have been run to the switches and necessary blocks for the wye. On one leg of the wye today we installed about twenty feet of conduit at (unfortunately) a 3.5% grade using the Kevin Strong method for roadbed. Once the snowstorm passes I will build up the roadbed and lay some track so I can at least use all three legs of the wye.

Other than wiring the control panel for the junction, we will be at a standstill until I can get a skid steer into the yard.

John