Tomix track layout geometry problem - 1245 / 1246 Double Slip

[The_Ghan]

This is killing me.  No matter what I do, I can't seem to resolve this damn problem I'm having implementing a couple of Tomix 1245 Double Slips.  See image below and note the gap in red.

 

I've tried swapping either or both for 1246, to no avail.  Any ideas?

 

Cheers

 

The_Ghan

[David]

It's the 1272 switch (the lower one connected to both slip switches) that's throwing things off the usual Tomix geometry. You could swap it with a 1271 so that the switch is no longer connected upside down in relation to the curve geometry, but that would change the look of the layout. Unfortunately I don't think there is an easy way to do this, the same thing happens with Kato switches if you use a a switch upside down in relation to the rest of them.

[The_Ghan]

Actually, according to the Tomix catalog it should work.  The problem may be with AnyRail instead.

 

Cheers

 

The_Ghan

[rankodd]

Actually, according to the Tomix catalog it should work.  The problem may be with AnyRail instead.

 

Cheers

 

The_Ghan

 

That'd be fine, except that XTrackCAD agrees with AnyRail - it doesn't fit, and with a big enough margin that it seems unfudgeable. Do you have a link that shows how Tomix thinks it goes together?

[Martijn Meerts]

Railmodeller also says it's not doable (I don't have a screenshot to prove it though ;))

[David]

With the real track it is fudgable best I've seen, however the degree that the joints are bent is higher then the safety factory in any of those programs and for good reason. You'll end up with a visible gap on one side and it will pose a derailing hazard.

[The_Ghan]

Thanks folks,

 

It seems at least we can rule out AnyRail as the culprit since other software is producing the same problem.

 

I'm at work right now, so I can't give you the exact page reference in the Tomix manual, but it is towards the back where they have the sample layouts and track fragments.  It isn't exactly what I'm trying to do but it is the same as figure 7 here - http://www.trainweb.org/tomix/track/Snippets.htm.  I'm thinkin I might try to reproduce that snippet first and build on it.  There must surely be a way to do it as what I'm proposing is not an uncommon scenario.

 

Any help would be greatly appreciated.

 

I might have to buy a few double slips and try to sort it out by hand.

 

Cheers

 

The_Ghan

[David]

Snippet 7 has the turnouts and curves the 'right' side up. In order for the geometry to work the curve portion of each turnout (or a R514 curve) should meet the diagonal piece pieces, either from a slip switch, other turnout or crossing. Connecting the straight portion of a turnout to a diagonal creates gaps.

[The_Ghan]

Here is a reply I've just received from HS:

 

Thank you very much for your inquiry.

 

Regarding your TOMIX Fine Track geometry problem, our train model division manager suggested replacing 1245 with 1246, although he added that he never tried so he is not sure.

 

Apparently manufacturers rarely offer solutions to original track layouts problems.

There are infinite possibilities to track layouts, and solving problems is part of the fun.

 

We hope for the development of your track layout, and if there is anything else we can help you with, please do not hesitate to contact us.

 

 

Cheers

 

The_Ghan

[The_Ghan]

Hi David,

 

I get that.  If I replace the 2x 1272 with 2 more 1271s and then add 15^o curves it works.  However, that's not very prototypical.  I'm going to investigate cutting down one of the 1271s and fudging it.

 

Cheers

 

The_Ghan

[brill27mcb]

It's the track geometry that does not work, not any layout software. There are two ways to design a turnout, and each has its advantages and disadvantages.

 

Method 1 is to have the curved route of a turnout end at a point straight out transversely from the end of the straight route. Tomix turnouts are designed this way, as is the Kato #6 turnout and all of the 15-degree crossings. That's why there are "left" and "right" crossing pieces.

 

Method 2 is to have the curved route and the straight route end symmetrically, so that transverse lines from each cross midway between the two routes. The Kato #4 turnout is designed this way.

 

With Method 1, using turnouts to make a cross-over or siding, creating parallel tracks, keeps the ends of the track pieces making the parallel tracks in synch. But, if you flip one turnout as your drawing does, so that a curved route on one turnout leads to a straight route on the next turnout, the synch is thrown off. Hence the gap in your plan.

 

With Method 2, you can flip a turnout and it will work, however, all of the synch is messed up to begin with. That's one reason the Kato #4 comes with little straight pieces to compensate.

 

Rich K.

[The_Ghan]

Rich,

 

It's the little things that keep me awake at night .... and at around 2:15am today I had an idea!  

 

See the first image below.  :evil5:  I added a 1024 (70mm) and 1023 (72.5mm), in red, between the 2 x 1245s.  I also replaced straight track to correct endpoint geometry, in green.  This does two things:

 

1. it evens up the connections to the upper 1271 and lower 1272 - which were throwing out the geometry in the first place;

 

2. it creates a standard 55.5mm space between the horizontal 1022 and 1023 - the standard Tomix platform space.

 

I'm going to have a station here anyway, but with this solution I would have two outside platforms, which I didn't want for this layout as the station is right at the front and I didn't want the platform hiding the undercarriage equipment when the trains were stationary.  So, I used 1150s (R605 10^o) and some straight track, all in blue, to reallign the track as I desired.  See the second image below.  :evil5:

 

Now I can sleep easy!

 

Cheers

 

The_Ghan

[brill27mcb]

The second plan has that true-to-life look, not so perfectly geometric. If you put a straight piece to the left of the upper double-slip before the 1150 curves, you also avoid almost all immediate left/right zig-zags, which should also improve operational reliability. The Tomix track system is very flexible, and difficult situations can be overcome with enough thought. Trying out your plans with real track will be the true test of how they work.

 

Rich K.

[The_Ghan]

Yes, I really like the second plan also.  I particularly like the space between the bottom double-slip and the west-bound main line and can imagine a little signal box or something in there ... like this: http://www.1999.co.jp/eng/10009840

 

I'm also thinking I need a piece of straight track on both sides of the lower upper double-slip, expanding on your suggestion.  I'll see what I can come up with.

 

Thanks for your input.

 

Cheers

 

The_Ghan