I posted about a step-up on a 130ft TT from Atlas Code 83 to the TT.
I did some research and the following are the results; RAILS only
Atlas Code 83 .0825 (avg 5 readings High was .0831 low was .0822.)
Walthers turnouts .0794
Turntable #1 .0851 ( the step-up)
Turntable #2 .0828 No problem
Turntable #3 .0824 Will be no problem.
Talking Ties with the rails:
Atlas 83 .1735
Walthers 83 .1475
Turntable No reading it is a deck.
???
These are the REAL thickness of the Rails and track for planing a transition from the yard onto the turntable. Shows the difference of each CODE 83 product.
A Centipede tender with a drop WITHOUT a rail joiner is VERY unhappy. Track to turntable=no rail joiner.
Early in my Air Force career I was assigned as a Computer Maintenance Repairman/Technician in a Titan I missile squadron at Moses Lake, Washington. We had a Chief of Maintenance who once threatened to Courts-Martial the next person he heard say “Close enough for government work” and he put out a directive to that effect - this guy was tough as nails and probably would have at least tried to do it. One phrase he never quite caught on to - although perhaps he just overlooked it - was “Don’t sweat the small s**t!”. Meant substantially the same thing but was just a little broader in its concept.
When you are talking about these minute measurements in Code 83 sizes “don’t sweat the small s**t!!!”
While your attention to detail is terrific, it’s highly unlikely that you’ll be able to build benchwork and turntable mounts, or lay roadbed to the tolerances of 0.03 to 0.0009 inches that you’ve measured. What you’ll more likely be doing is building to normal tolerance, and then making final adjustments with metal shim stock, and thin wood or styrene striping.
In other words, you can’t plan your work as closely as you’re implying. (Or. to put it another way: “What he (meaning RTPoteet) said!” )
-Ed
I’d just use a big hammer or a few shims…
If your Centepede tender doesn’t like the turntable, there’s probably a slight cantilever action of the wheel assemblies due to a height change when entering the turntable.
I’d start with shimming the turntable where the motor shaft penetrates “the Pit” until your transition point is equal between turntable deck rails & entry track rails at one location…or vice versa shimming everything BUT the turntable so as to equalize height with the turntable rails.
To avoid repetitive work, I’d consider selecting just one track on which to park the Centepede if it’s the only problem…
…or just drag out the sander and file all pertinent rails until they are equal at the point of operation.
George,
The ‘real’ measurement is not the thickness of the rail. It is the measurement at the top of the approach rail in relation to the top of the rail on the TT. There will be variations in the rail(that is manufacturing). Various code 83 track also has different thickness ties as well. And you have to take in consideration the thickness of the TT mounting itself. So, one needs to look at the final ‘top of rail’ measurement to make the approach track and the pit rails match. BTW, the prototypes had issues there as well. I have watched many prototype engines ‘clunk’ as the move on/off of the TT bridge. If your final installation is within the range of .0025 - .0057 that you measured, I sort of doubt you will have problems with that centipede tender(this IS straight track?).
Jim
Atlas code 83 and code 100 are the same height at the rail head if that helps any.
{Edited… I forgot the code 100 part. Sorry!}
Tell that to the Pilot truck on the Athearns Challenger [:D]
I am right now scratching my head in utter confusion but it’s not the first time today I have been there. Just what are we supposed to be telling the pilot truck on an Athearn Challenger??
If I read your post correctly you state that the heighth of Atlas Code 83 rail is .0825 inches; the heighth of the Code 83 rail on the turntable is .0851. That is a “step-up” of ,0026 inches. That is 26/10000 of an inch, a machinists measurement. This is 1/384th of an inch, less than half the thickness of a sheet of 20# Bond Paper. If your Athearn Challenger is having difficulties rolling its front truck onto your turntable with a 26/10000 of an inch “step-up” it is time to grab the trusty ol’ NMRA standards gauge and start doing some serious checking!!!
Problem Solved. Bridge track out of gauge.
claycts :
Your efforts are laudable, but EXTRUDED material such as RAIL varies in thickness as it is spewed out. Mfg.tolerances come into play - if they are accurate. In short, the ‘advertised spec’ is nominal. Tightening the specification can be done, but reduces yield - so increases cost, and (guess what?) to YOU.
This may, or may not, be a good reason to stay with one brand
“Dont ya just love it when a plan comes together”
Karl