Can the Kato 20-210 be fixed for pure DCC?

[defor]

I (somewhat obliviously) bought a few 20-210's for both of my in-progress layouts, and while one of them can be swapped with a set of single crossovers, my b-train layout practically relies on one...

This said, my problems are stemming from the power routing that occurs when the crosses are not complete, as is one of the normal 'running' turnout configurations I'd like to be able to leave the switch in.

It also appears that the features of the #4 that make it perfectly suited for DCC (power routing off, frog unpowered)  simply cannot be accommodated without extensive modifications.

 

Has anyone attempted to 'correct' the 20-210 to allow for independent turnout control and complete removal of power routing?

 

Unless I'm mistaken, it appears the summary of changes needed is:

• Insulation of the points so that a short does not occur when entering from the middle of the crossing if the points need to passively be pushed out of the way (I simply can't come up with a good way to do this)
• insulate the closure rails in each turnout from each other (looks reasonably trivial)
• isolate and insulate the frog (looks pretty straightforward)

 

Of course, internal wiring will need redone, but it looks like most of it can be removed.

I'm hoping theirs a better answer- or is there:s a reasonable replacement that fits my needs for independent control and can be fit into a unitrak layout.

 

Anyone?

[kvp]

So basically you would like to be able to control the 4 turnouts indepedently and cut them when set the wrong way?

 

Rewiring the drive coils is easy as there are 4 coils on 4 circuit boards wired in parallel. The plastic even has the slots for the extra wires. There is no power routing in the turnout, except for the frogs. This can be disconnected on the circuit boards but will leave huge chunks of the turnout without power. A better solution would be to add 4 automatic DCC frog polarity switcher circuits so the polarity will sort out itself.

[defor]

what do you mean "cut them"?

I was definitely planning to remove the parallel wiring or course-

The frogs-- which in this case are pretty massive given the fact the points are one conductive surface, connected to the closure rails, which are then the same part as the frog itself, is the core of my problems... at least on most powered frog switches, the closure rails and the points have each rail insulated from each other, but kato seems to have foregone this in favor of ?cost cutting? (I wish my wallet saw the cost cutting)

 

The effect of this seems to be that if we consider the double crossover as 4 separate turnouts, we see that if a turnout is set for track A, but a carriage enters the switch from track B, regardless what A and B are, the effect of the wheel pushing the points out of the way, will cause a short between the outer rail and the entire point/closure/frog, and the opposite side wheel will be electrified the same.

If the wheelbase is wide enough, this could cause the points to come in contact with the opposite rail, causing a systemwide short.

Of course this is assume no powered pickups- our problems multiply when the carriage has powered bogies or is a locomotive, which, while a reversing circuit on the frog MIGHT assist with same-rail path shorts, it still looks like the unified points/closure/frog will still cause a short here as well.

 

I was actually unaware of these frog polarity switchers...they look like they would also be good for #4 turnouts instead of using insulfrog mode, or am I mistaken there?

 

can you recommend a small quad-channel frog switcher my use case if I'm incorrect in my assessment of the problems with entering the turnout from the non-switched direction?

 

 

 

Edited June 28, 2018 by defor

[kvp]

Cutting a turnout means running trough from the direction which is not selected. This is when shorts could occur, due to the polarity mismatch. The obvious fix is to never cut the turnouts and always set them correctly. On the prototype only tram and old interurban lines use sprung turnouts that could be cut without a derailment.

 

The single piece point rails are from the old Kato turnout range, like on the #6-s. If you isolate the backs of the point pieces with paint, then the whole frog and blade assembly could be connected to a polarity switching circuit without further modification and it will work.

 

For frog power switching, the dual and hex frog juicer or the dcc80 modules are good.

[defor]

This has been a rather enlightening conversation as I actually was unaware that 'cutting' was non-prototypical.

 

I also spent some time reconfiguring today and was able to fit in two single crossovers, but definitely ran into that 'don't put a curve before a #4 point unless you like derails' problem.

The double crossover is simply far more leniant (out of the box) owing, as you say to its #6 influenced design.

 

Given that as usual, the layout in question will have some bit of automation at least, I'm thinking that I should simply approach the issue from the perspective of verifying turnout directions ahead of time, and well, 'stop being lazy!' by cutting.

[Oz_Paul]

I use the Tomix 1247 (which seems to be very similar) on my DCC layout with no additional modifications. I have power feeds on all four legs of the cross over and it seems to work fine for me.

 

I have block detection on the entire layout except on and around the cross over which had to be isolated. The issue was that all tracks leading out of the cross over used to show as occupied when a train passes even if set to run straight. 

 

Paul