I have bought a Tillig Elite double-slip type DKW II and am about to istall it in a test-running configuration.
I chose it because of its very useful geometry, forming a 15 deg crossing angle and nevertheless the curved routes have very generous 42" radii.
I have studied and compared it with regular doubleslippers and found that the Tillig is of the so called Baeseler type, in which the outer rails of the two curved routes never cross, only just touch. Thus the curves can start all the way back which is why the radii can be so generous. Baeseler slippers sure occur in the prototype as well. See the nice Wikipedia description and picure: http://en.wikipedia.org/wiki/File:2001-07-19.0004.DKW-Baeseler.jpg
The reason they are not very common in the prototype seems to me to be that although they are good space savers at more steep crossing angles they get very long at shallower angles.
But they should thus often be good for model rairoads! Especially for my yard throat, I think.
Anyway, I have run into two flaws with my exemplar.
First, the electrical connections from the frogs to the cast middle rails consist of two thin metal strips, which seem to be point-welded to the rail undersides – has not quite worked. One of them was loose right away and the other came loose right after I fixed the first.
I didn’t dare try soldering them back, too little space between the plastic tie structures to get in there even with a narrow electronics solder unit.
Instead I drilled a hole and tapped it for an M 1.4 brass screw from below that fastens a strip of thin brass, which in turn was soldered to the loose end of the original strip.
Both done, all ok I thought, but:
Second, it turns out that the rail pieces that form the points of the (outer) frogs are not soldered or joined in aný other way, thus one of th
to most people in this forum, Tillig track is widely unknown. Tillig is a German brand and their design (tie arrangement) follows German prototype practice, which is different to the US practice.
I have used Tillig switches in the past and found them unreliable, for the same reason as you have stated. Most of the issues could be solved, though, by soldering extra feeders to the frog and rails. Soldering a feeder to a rail btween two ties is not a big issue, if you place two wet cotton balls on each side to the point, where you want to place the feeder.
Thanks for the advice!
Here is the present situation:
My Tillig Baeseler type double-slipper is now working in a test setup. But only after a lot of work. Turned out there were four cases of failed necessary electrical connections. Following your suggestion I soldered in extra feeder wires in all those cases.
Although there is now proper electric contact to all rail pieces, I remain a little nervous about how it will fare in the long run. This is because the way it is manufactured, no pieces are soldered together. The design seems to be to connect many of them with the point-welded straps on the underside (3 of 10 were faulty; now replaced with my extra feeders). But in other cases, electrical contact is made only through mechanical contact, and that seems unreliable. This is for the four inner point-rails which are inserted but not soldered in the frogs, and also by touching the stock rails at the point end. Will that work in the long run?
This much done, I installed it with lengths of flextrack in all directions and started to test run it with short trains (all with American standard RP-25 wheels, mostly Kadee 33’ wheelsets.
And only rarely did a train pass without derailments.
The resason was pretty clear: All the eight points were way too blunt. The railheads were not filed at all on the inside (running-), forming a blunt points that flanges were hitting almost every time.
So I had to do a lot of delicate filing on the points, in place (found it useful to insert a toothpick between the stock rail and the point to keep them apart during filing). I filed them real sharp, starting the taper a good inch from the point.
And then it started to run ok!
Before I install it finally I will have to do some more work on it though!
— Give it a good workover with the NMRA gauge, it is is a bit narrow at several points.
— Check and correct vertical