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Kind of weird thing is happening on my layout that I just finished. The locos will slow slightly just before the turnouts, over them, and slightly after. And more so where I have 2 turnouts back to back. Ive checked the voltage with a meter at several spots and it is the same wherever I check it, as is the resistance. I tried moving the power closer to the turnout and that has no effect either. I also checked the rolling resistance and that seems to be fine also.
Any ideas, Thanks
Gerry
Check the gauge of the track through that section to make sure it hasn't decreased and is compressing the wheels on the locos. Sometimes, the rails will just lean inwards a little and cause pressure on the wheels and make them work harder to roll through there.
Gerry, you didn't say what kind of switches you have. That sometimes gives us a little more information. Although this could be a gauge problem, I suspect it's something electrical. Check the voltage right at the rail joiners, that's the most likely place for a drop. If you have something like Atlas #4 snap switches and they are the first switch after a curve, the locomotive will slow down on the diverging route because you have an "S" curve and increased rolling resistance, even if you can't feel it rolling a freight car by hand. It would probably help if you made a sketch of your track plan with the location of the switches and posted it here.
Here is the layout. While running counter clockwise it will start to slow on the outer leg curved section just before turnout #2 and continue untill its past turnout #4. It does not slow to a crawl but it is definately noticable. They are Atlas #4 turnouts. I have checked the voltage in several spots in the problemm area and it is the same as everywhere else. I will check it at the joiners this afternoon. One thing I find weird is no matter where I check the voltage it varies slightly and the meter will not settle on a solid number. Its not much maybe .3 in either direction
Does the engine do the same thing running clockwise or only when running counterclockwise? Where is your power feed compared to these turnouts? What kind of locomotives are you running? This still sounds like an electrical problem but the question is, what's causing it? You should be able to get a solid voltage reading with the throttle wide open and no trains. What does the voltage reading do as your train approaches and then leaves the area of the switches? Have you given all the tracks a good cleaning? Keep at it and we'll figure it out.
You have to check the voltage under load. with nothing running in the area the voltage will show the same as everywhere else. With a load (Engine in problem area)you might find that the voltage is lower. The engine motor doesn't know where it is. It only knows what it is being fed. If it's slowing and not due to rolling resistance as noted earlier, then it's a voltage drop. Just having a couple of loose fitting joiners will cause it (they don't necessarilly have to be at the turnout, just on the way to the turnout.
Good Luck
I have some of my bigger steamers slowing appreciably, if that word can be deemed appropriate under the circumstances, in my #7.5 W/S curved turnouts. I always felt that it was due to the tight curvature, but the fact is the inner diverging route is supposed to be above the stated minimums for those engines. They are not, but I learned this early enough to do surgery on them and extend their radius by about 2-3" before I set them in place and ballasted them.
I found out, one time when I decided I wanted definitive knowledge instead of conjecture, that the gauge of the rails at the points was a considerable incursion into the gauge that ought to have been the case in a tight curved turnout. So, those affected engines were close to binding in the points rails section, but not due to the tightness of the curvature on those diverging routes...it was because the points rails were too thick, or perhaps insufficiently separated when built, or maybe even tilted a bit as suggested above. But, my NMRA gauge clearly showed they were tight, and my engines feel the same way.
If I run the loco backwards it does the opposite(speeds up through the turnouts and slows on the curves) Tried different power packs and locos all do the same. With the loco running I do see the voltage drop or increase as the loco goes arround. Voltage fluctuates about .5 volts. Having a difficult time locating the trouble spot. Power feeds are exactly where they are in the pic. Thanks for the help. Going back in with the meter
Kind of embarrassing what the problem was. My .75 inch plywood warped (crowned, higher in the middle) As the loco would go down or up the grade the voltage would change, making me think I had an electrical problem. Didnt notice this standing over the layout, but one day I sat down on a chair and noticed the warp and the light bulb came on
Just figured Id post the cause of it. Other than that they run great so im going to leave it as is. Thanks for all the responses.
I'm glad you found the problem and came back to let us know. This is a good illustration of two rules in model railroad. First, the apparent cause of a problem is usually not the real cause. Second, you should always use a long carpenter's level when laying down plywood to make sure it's really level in all aspects. It almost never is and it's a lot easier to sand it level when there's nothing on compared to when there's lots of stuff on it.
