Wider radius Ross Switches

I would go with a numbered switch if possible

What he said Chris.

We had an issue with a #8 curved turnout. Basically, short-wheelbase locomotives lost the hot and/or common connection going through the turnout.

The fix is pretty simple since Ross turnouts (NOT the ROSS READY) are fully insulated. You place a hot connection on the unused closure rail (between the point and the frog) -- i.e., the diverging closure rail for the non-diverging route and vice versa. This can be done with a Tortoise machine's relay contacts. For additional benefit, the closure rail that the wheels will be rolling on can be connected to common, which we did. When I put this wiring in, we had ZERO stalling on that turnout. Using Ross 11-degree (#5) turnouts everywhere else should serve you well with larger equipment. I'll look for the wiring diagram, but there might be one up on Ross' website.

The Tortoise contacts can handle the current load as it's of short duration. Ours has worked for years without a problem.

Okay... So how do I figure out what numbered switch I need? I'm thinking the equivalent to an O-80, or something close.

Matt, I presume I would need to solder a lead to each of the closure rails, and that these leads connect to the relay, correct? If I'm using a manual ground throw, what activates the relay? Or maybe these all get the NJSwitch machines, end of discussion? Looking at all my options.

Chris

LVHR

I created my own relay board for switching the powered and outside rails, adds relability over just switching the center track power.

Replacement for DZ-1008 Relay for Ross Switch Powered Rails

John,

It looks like I will be paying you a visit after I figure out what switches to order!

Chris

LVHR

The numbered turnouts aren't curve-replacement turnouts. They diverge at a fixed angle rather than through an arc. The 11-degree turnout diverges are 11 degrees straight off, so it won't generate a perfect curved arc (see images below). If you're running strictly 3-rail equipment with truck-mounted couplers, using a curve-replacement turnout is easier with regard to planning and implementation. If you decided at some point to run scale wheels and Kadees, though, curve-replacement turnouts can bite you in some circumstances because the arc of the curve extends through the frog and scale wheels can pick it, especially when pushed or at higher speeds. The #5 works just fine with scale wheels in my experience at AGHR over the past several years.

Ross O-80 With 11-degree turnout:

Ross O-80 with O-80 Standard (Curve-Replacement) Turnout:

I have been playing with my post-war 2026 conventional engine recently. My old 1033 transformer powers the little guy around two hundred feet of GG and Ross switches. I have 072, 080, #4, #6, and a curved #6. The 2026 runs through all of them with no hesitations even at low speeds.

@lehighline posted:

John,

It looks like I will be paying you a visit after I figure out what switches to order!

Chris

LVHR

You're welcome anytime.

John,

Thank you!

Based particularly on Matt's diagrams and comments (Thank you Matt!), I think the O-80s will fit my needs. I'm not seeing much difference between them and the 11 degree turnout, other than the slightly increased radius.  I do plan to stay with 3-rail equipment and no K-Ds. It does seem that my concern regarding use of short wheel based engines is not as bad as I feared and that both turnout types would have the same issue, if at all. My plan does call for one O-72/O-54 double curve turnout, which I have been warned could cause me trouble. But I think GRJ's relay board will fix that issue if it occurs.

Thanks for all the input, guys!

Chris

LVHR

@gunrunnerjohn...I am putting some of these boards together, but I cannot find the part: HDR-1x2-2.5mm.??? Is there another name or part #? I have searched Digikey and Mouser, but I'm sure I am not looking at the proper category. Thanks for you help!

Great thread, everyone.....learned lots!

Peter

That's a pattern for the connection pads, there is no actual physical header for that location.  That should have been removed from the BOM.  You just solder the wires to the pads.

@AGHRMatt posted:

The numbered turnouts aren't curve-replacement turnouts. They diverge at a fixed angle rather than through an arc. The 11-degree turnout diverges are 11 degrees straight off, so it won't generate a perfect curved arc (see images below). If you're running strictly 3-rail equipment with truck-mounted couplers, using a curve-replacement turnout is easier with regard to planning and implementation. If you decided at some point to run scale wheels and Kadees, though, curve-replacement turnouts can bite you in some circumstances because the arc of the curve extends through the frog and scale wheels can pick it, especially when pushed or at higher speeds. The #5 works just fine with scale wheels in my experience at AGHR over the past several years.

Ross O-80 With 11-degree turnout:

Ross O-80 with O-80 Standard (Curve-Replacement) Turnout:

Matt.......you are to be commended. This is by far the most lucid description of this issue that I have ever read.....Bravo!

Peter

@AGHRMatt posted:

If you decided at some point to run scale wheels and Kadees, though, curve-replacement turnouts can bite you in some circumstances because the arc of the curve extends through the frog and scale wheels can pick it, especially when pushed or at higher speeds.

I understand that straight angle turnouts are more prototypical and offer better tracking in crossovers, preventing S-curves and the like. What about the curve extending through the frog allows scale wheels to more frequently pick the switch?

@rplst8 posted:

I understand that straight angle turnouts are more prototypical and offer better tracking in crossovers, preventing S-curves and the like. What about the curve extending through the frog allows scale wheels to more frequently pick the switch?

Honestly, the gap and guard rail slop required for 3 rail flanges to pass through the switch frog is probably the biggest culprit. I measured a code 148 switch that I built, and the gap the flange has to jump is about 1/4" (from the narrowest spot on the frog where the wheel leaves the rail to where it picks back up at the 'V' in the rails). On an atlas #5 its about 5/8". On a scaletrax #4 its just over an inch.  Thats a lot of space for the wheel to drop in and wander. Free the wheel from the rail for almost its diameter or more (a 33" wheel is .6875) and even with the guard rail holding the other side (c148 guard rail gap .070", atlas #5 .115", Scaletrax #4 .135"... On a machine made atlas 2R switch, the guard rail gap is .085"), there's enough space for a scale flange to drift about. The wheel set will try and keep going straight, so it ends up on the wrong side of the frog point and picks it.

If you went full 3RS and shimmed all the switches to handle the scale flanges, I suspect that you wouldnt have a major issue with it.

@rplst8 posted:

I understand that straight angle turnouts are more prototypical and offer better tracking in crossovers, preventing S-curves and the like. What about the curve extending through the frog allows scale wheels to more frequently pick the switch?

Up front, keep in mind this only applies to "facing point" moves. Trailing point moves aren't a problem.

The "trough" in the frog that the flanges pass through is over 1/8" wide on both curve-replacement and numbered hi-rail turnouts,. This allows for the flange position on hi-rail wheels of all vintages to pass through cleanly. However, because the frog is curved to accommodate the arc you're trying to fit it in, the curve must continue through the frog design (unfortunately I don't have one handy to show you a photo. The curve continues in an invisible line through the frog which is OK for a hi-rail wheelset (the guard rails keep it far enough over to prevent it from picking). A 2-rail wheelset has narrower wheels and the back-to-back spacing between them is wider than that of a hi-rail wheelset. Therefore, the guard rail can't pull the axle in far enough to keep it from picking the frog.

On a numbered turnout, The path through the frog is straight as are the closure rails. So, on everything up to a #5, the gap in the frog just looks like a gap in a straight rail and the wheels stay aligned. Even if the guard rails come into play, the wheels are positioned such that they won't pick the frog. The exception is Atlas turnouts because the guard rails are too low to catch the flanges on scale wheelsets (they can be shimmed and they'll work). Ross turnouts have rail-height guard rails and have worked consistently in my experience at Angels Gate. MTH ScaleTrax turnouts have rail-height guard rails and a little beveled ramp within the frog on their numbered turnouts and will work with scale wheels (they designed for that). In my testing and Rich Battista's layout operation, scale-wheel locomotives and rolling stock do fine on the numbered turnouts. Since I'm the only one so far running scale wheels at Paradise and Pacific, I'm not pushing the issue of shimming the guard rails on our Atlas turnouts, though if a turnout is being removed for repair, I've recommended shimming the guard rails during the repair process.

On MTH RiteTrax/RealTrax O-72 turnouts, it looks like they cut the gap between the guard rails and the stock rails a little narrower and I've heard MTH locomotives with scale wheels can squeak through them at low speeds. I've also managed to sneak a scale-wheel locomotive through a Ross O-72 turnout at very low speed (go figure). I haven't done any testing with FasTrack O-72 turnouts as they are actually sharper than O-72 since they're measured at the outside rail rather than the centerline.

@Boilermaker1 posted:

Honestly, the gap and guard rail slop required for 3 rail flanges to pass through the switch frog is probably the biggest culprit. I measured a code 148 switch that I built, and the gap the flange has to jump is about 1/4" (from the narrowest spot on the frog where the wheel leaves the rail to where it picks back up at the 'V' in the rails). On an atlas #5 its about 5/8". On a scaletrax #4 its just over an inch.  Thats a lot of space for the wheel to drop in and wander. Free the wheel from the rail for almost its diameter or more (a 33" wheel is .6875) and even with the guard rail holding the other side (c148 guard rail gap .070", atlas #5 .115", Scaletrax #4 .135"... On a machine made atlas 2R switch, the guard rail gap is .085"), there's enough space for a scale flange to drift about. The wheel set will try and keep going straight, so it ends up on the wrong side of the frog point and picks it.

If you went full 3RS and shimmed all the switches to handle the scale flanges, I suspect that you wouldnt have a major issue with it.

Agreed. I suspect that if the guard rails were narrowed to even 1/10" they'd work with scale wheels. On a #6, the gap is bigger (don't get me started on a #8). The alternative is to make frog points for the wheels to just ride on. Back in the days when dinosaurs and I roamed the earth early turnouts were "flying wing" style where a plate moved (like American Flyer switches) and left a very small gap for the wheels to negotiate. If they had guard rails at all, they were for decoration.

@Putnam Division posted:

Matt.......you are to be commended. This is by far the most lucid description of this issue that I have ever read.....Bravo!

Peter

Thanks Peter. I just wish you could modify turnouts without removing and disassembling them.

@Boilermaker1 and @AGHRMatt thank you for the explanation. It sounds like the root cause is basically just increased gap size, and curved turnouts just have more of that.

Having come from the HO world (granted many many years ago) everything I ever learned was that the turnouts were built to work with a certain wheel tread and flange size, and mixing them is just asking for problems. When I learned a few years ago that some folks ran 2-rail equipment with "scale" wheelsets on track and turnouts designed for 3-rail I was really surprised it worked at all.

If you have got the space...go with the O-100.