Kato Unitrack Length Issue - Fact or Fiction?
*Note – The following is the text of a message that was originally posted to the T-Trak Yahoo Group (moc.spuorgoohay|kart-t#moc.spuorgoohay|kart-t) as message #8898 on February 18, 2015.
Our Executive Committee on T-Trak Standards, otherwise known as "CSI: Kato", met this past Monday morning for bagels and coffee. I ordered my usual, a Sesame bagel, double-toasted, with a 25% Plain schmear. David had his usual lox and creamed cheese on a Poppy bagel; Bob and George also ordered up their usual choices. And, Brenda was glad to see all of us as we were to see her, but I digress.
We were made aware of the "Missing Millimeters" phenomena involving Kato Concrete Double Track by Steve Jackson and several previous posts to this list. The chief action on our agenda this Monday was to investigate this situation and report our findings to the T-Trak community. The game was afoot.
In an effort to insure the proper scientific rigor of our investigation, we used new, off the shelf, unopened packages of 62, 124, 186, and 248mm Unitrack in both the single as well as the concrete double track. We were well-equipped with micrometers and other metric measurement tools; four pair of eyes had to concur before we recorded our findings.
Here's what we found:
62mm Straight (20-040) measured at 62mm
62mm Concrete (20-042) measured at 61.5mm
124mm Straight (20-020) measured at 124mm
124mm Concrete (20-023 measured at 123.5mm
186mm Straight (20-010) measured at 186mm
186mm Concrete (20-012) measured at 185.5mm
248 Straight (20-000) measured at 248mm
248 Concrete (20-004) measured at 248mm
When combined into 310mm lengths:
248 and 62mm Straights measured at 310mm
248 and 62mm Concretes measured at 309.5mm
186 and 124mm Straights measured at 310mm
186 and 124mm Concretes measured at 309mm
186 and two 62mm Straights measured at 310mm
186 and two 62mm Concretes measured at 308.5mm
The .5mm difference between 310mm of Straights and Concrete may not be all that significant, but we witnessed the effect of the problem first hand when trying to attach concrete track to a T-Kit single recently. The concrete track combination did not provide enough length for the essential overhang at the edges. We recommended that the sides be sanded to 'thin down" the module top and we are awaiting the results of that action.
The moral of the story should be obvious. Take care when using the Concrete Double Track, especially if building longer modules, which would only compound the error.
Mike Moore
North Texas T-Trak Modular Railroad Club