TT scale trains and models

Started poking through my new layout bits and came up with some questions regarding the Tillig EW2/3 turnouts:

1. What wire diameter fits the crossbar? The wires supplied with the MTB MP1s are too large and I'm loath to try and ream out the holes.

2. I noticed that the wing rails are jumpered together. Is the normal practice to remove the jumper and cut a gap right behind the frog point and not power the tiny bit, cut a gap right after the jumper and use the jumper to power the frog or some other solution?
I was leaning toward gapping right after the points.

I read the excellent tutorial regarding building them, but nothing directly addressed my questions.

Thanks all.

In response to #1 - not sure of the diameter. I usually just ream them out. Haven't had a problem. Just be careful and you should be ok.

In response to # 2: I'm not ready to cut a gap in the wing rails. So I prefer the variant with the polarization of the wing rails with a 2 pole changing switch/relais (DPDT). The jumpers to the wing rails will be removed.

See the scheme at http://fktt-module.de/node/190

That's one of the many different options I've seen, better explained than most, thanks. One option I've been looking at is to use a DPDT switch where one side controls the MP1 and the other side powers the wing rails. Cuts down on the electronics and ensures everything is in sync.

I did buy an extra turnout though... Maybe a bit of surgery will lead to a breakthrough or a broken turnout or both.

sacto-tt wrote:1. What wire diameter fits the crossbar?

I use 0.9 mm wire (36 thou-ish). It fits the hole and it is stiff enough to operate smoothly. I set the travel on the MP1 to 9 mm.

sacto-tt wrote:2. I noticed that the wing rails are jumpered together. [...] or some other solution?

I have the ready-made EW3 switches (not kits) and did not modify them at all. I use the MP1 internal switch (terminals 4, 5 and 6*) to switch the polarity of the wing rails. Terminal 4 feeds the power directly to the jumper between the wing rails. Terminals 5 and 6 get the power from the track (there is a 50% probability of getting the polarity of T5 and T6 right in the first try ).

I also powered the points. Tillig thinks that the points get power from the stock rails by firm contact or by magic. Unfortunately my magic wand was in for service that day, so I had to hard-power the points.

(*) - For this example I arbitrarily numbered the terminals 1 to 6 starting from the red end of the motor.

Oh yeah - points have to be hardwired unless you want shi++y contact.

And just to save you some headaches later, if you power the motors from track power, don't forget to feed the motor side of the MP1 though a rectifying bridge. The motor is sensitive to polarity. Terminal 2, helpfully labelled COM (+), must be the (+), or the motor will not turn.

This is more important for modular displays, where you do not have control how the track polarity is set up from one display to the next. Yes, it has happened to me.

Thanks! That's exactly what I needed to know

Power the motors from track power? C'mon guys....just run a bus.

ConducTTor wrote:Power the motors from track power?

The TT-Tracks standard does not have any busses, neither for track nor for auxiliary power. Yet.

I am working on it