Large Scale Central

Thomas wiring issue

General Discussion
#1

Whilst dealt with on another forum, something that is not covered is compatability with reverse loops. My loops are wired per the defacto largescale ‘standard’ (positive rail to the right side). Aware that Thomas is wired per NMRA standard, I was not aware it would short out my reverse loops when entering a reverse loop section. Correcting the wiring polarity to defacto standard has Thomas now traversing my loops, without shorting out my power supply. This issue did not even occur to me previously.

After a little thought, setting the wiring to ‘reverse’ polarity (NMRA standard), effectively reverses the direction of travel through my loops. I was getting the short circuit much as if I attempted to enter the loop from the wrong direction.

#2

This is a Bachman thing. The NMRA/LARGE SCALE switch was added to the Annie and has been included on most locos produced since. I guess they decided that no real Large Scale people would ever run Thomas with anything else on the same track.

I’m curious about your reverse loops. Do you have some electronics that automatically changes the polarity? My loops are wired with polarity reversing switches on an isolated section of track. I must stop, throw the polarity switch, reverse the power pack direction, then proceed.

#3

Does Bachmann do this stuff just to irk us?
How hard would it have been at the factory to wire them standard.

#4

Tim a fellow on MLS reworked Thomas to be a usefull engine and run like all the others by switching the pick up wires, looks fairly easy to fix.

http://www.mylargescale.com/Community/Forums/tabid/56/aff/17/aft/113445/afv/topic/Default.aspx

When to we get Dave’s review? :lol:

#5

Vic,
I did interchange the wires as shown on MLS.

Jon,
My reverse loops (similar to your loops) use a bridge rectifier (no complicated electronics employed). I enter the section, remove power and then reverse polarity to allow the locomotive to proceed. What had not occurred previously, as none of my locomotives were NMRA ‘standardised’, is that my reverse loops are effectively ‘reversed’ when using unmodified (NMRA compliant) locomotives. This may be a plus, in the future, as I will be hopefully able to alter my normal direction of travel through the loops.

#6
Victor Smith said:
Tim a fellow on MLS reworked Thomas to be a usefull engine and run like all the others by switching the pick up wires, looks fairly easy to fix.

http://www.mylargescale.com/Community/Forums/tabid/56/aff/17/aft/113445/afv/topic/Default.aspx

When to we get Dave’s review? :lol:


Aaaargh! Good thing I learned of this little wrinkle before I tried to run Percy with the Lionel/Playmobil/LGB/Aristo locos on my show layout.
Someone at Bachmann didn’t think this one through. Should I be surprised? :stuck_out_tongue:

#7

Interesting. Why oh why would they do this.

Jon.

#8

Why not? Except for the few of us that mix this with our model trains, the parents of kids that are getting their first train, don’t know the difference and if I under stnad this right, neither will the LGBers. So how many people do you think this really impacts? Maybe 12 or 14 people.

#9

Ric Golding said:
So how many people do you think this really impacts? Maybe 12 or 14 people.

Add me to the list (so make it 2 so far). We have a bride rectifier controlled reverse loop. So if I ever got a Thomas, not planning to, he wouldn’t work through the loop. But then again I don’t even know if our loop still works via track power. Almost everything we run now is battery powered and the old rectifier hasn’t been used in years. I wonder what it looks like? It’s buried underground in a small Tupperware container with tiny holes where the wires come out of. Sounds like a great spider hideout…eek

(http://www.3dtrains.com/forums/style_emoticons/default/ohmy.gif)

#10

Jon,
why you ask. Simple answer. Bachmann is showing, that like in their smaller scales, they are complying with universally ‘accepted’ standards. ‘Largescale’ standards have always been considered ‘Maverick’ standards to outsiders. B’mann started the education back with the polarity switch. Eventually we will see all largescale locomotives complying.

#11

Matt,

I think you can only count as a 1/2 point. Battery superceeds the issue and makes it not a problem. :wink: Cale is only a problem until 01-10, so we have to subtract him. I smell a lot more battery conversions just to resolve the situation. :wink:

Don’t take life so serious guys, if the wiring of a Thomas largescale train engine in a reverse loop is your biggest problem, count your blessings.

#12

I will utilise the opposite polarity wiring to advantage. I will leave half of my number of Thomas/Percy locomotives as delivered and modify the others to largescale standard. I will then be able to approach my loops from the opposite direction. I tried an unmodified (as delivered) version and it performed ‘normally’, travelling the opposite to normal direction, through my loops. Could be a blessing in disguise.

#13
Tim Brien said:
Jon, My reverse loops (similar to your loops) use a bridge rectifier (no complicated electronics employed). I enter the section, remove power and then reverse polarity to allow the locomotive to proceed. What had not occurred previously, as none of my locomotives were NMRA 'standardised', is that my reverse loops are effectively 'reversed' when using unmodified (NMRA compliant) locomotives. This may be a plus, in the future, as I will be hopefully able to alter my normal direction of travel through the loops.
Thanks. I had to draw this out before I could get my head around how it worked. Pretty simple really, just not something I'd heard of before. Because my reverse loop has sidings off it, I need the ability to run either direction, so I'll stay with my DPDT switch. Not a big deal because I'm there with the train anyway, not running a continuous circuit.

Outdoors my “loop” is really a wye with one tail as the reversing section. The diode bridge would work there too, but again I don’t want to limit my options for traversing the wye.

Good info to have stored in the gray matter though. Thanks!