When designing Fastrack layout on RR-Track layout software I occasionally encounter the need to “join” track that may be slightly off, whether by .05 inch, .2 inch, .5 inch or whatever. However, I am not sure what joint tolerance might be acceptable under operational conditions.
Is there a rule of thumb for how large a misfit could be before you reject it and redesign the track combinations?
Getting perfect fit on a complex layout may not always be possible, or could be extremely time consuming.
generally speaking the bigger the loop is the greater the mismatch the FasTrack will tolerate. In a small loop about the size of a 40X60 oval, anything greater than about 3/4 of an inch will give you problems but I have experienced mismatches of 2-3 and even four inches on my 12’X16’ “L” shaped layout that can be “Fudged” together with pretty good success. I like to have a handful of 1.75" track pieces handy to use as adjusters; you can add them in somewhere in almost every case to close the mismatch a little. Bottom line: It ain’t tubular but FasTrack does offer some flexibility. If it’s close in RRTrack software, then I bet it’ll work fine when you go to lay the track down.