Keeping cars coupled...any tricks?

[MinnMonkey]

I recently moved my layout and now I am having problems with a couple of my cars uncoupling themselves.

Before I moved it, everthing worked flawlessly. I do have 4% grades and 11" radius track on incline/declines. I know it is tight, but I have very limited space, and in all my testing it worked.

The uncoupling always happens at the same spots and with the same cars. Does this sound like a track problem, car problem or both.

If I end up replacing the couplers (truck mounted), is there ones that work better on steep hills and sharp corners?

 

[yellowlynn]

Sometimes there is a simple solution. You may have already done it. If the same cars uncouple, Switch ends. I have had this happen many times and I just reversed the direction of one car. Worth a try before digging too deep.

Lynn

 

[LoudMusic]

Have you watched to see how exactly they're uncoupling? I assume they're sliding virtically out of eachothers' grasp, so with that make sure that all your couple heights are the same. Often time people make a "coupler height measuring block device ... thing". A block of wood with a coupler mounted to it for quickly checking all the couplers in your fleet. You could also just use a car with correct height.

If they are of different heights you'll see them let go of eachother when the lower coupler's truck hits a dip in the track causing them to be just enough more out of alignment to let loose.

Adjustments are easily made by adding shims to the coupler boxes. I've used everything from sheet metal, to plastics, to cardboard and paper. It usually doesn't take much to fix them, but they need to be pretty darn close to the same through your layout. If you plan on having visitor freight (friends' rolling stock on your layout) or take your stuff somewhere else, you'll want to use a universal standard.

http://www.nmra.org/standards/S-2All_Scales.html

Looks like N scale is 0.216 inch coupler height. Unfortunately I don't know what that's a measurement of, ha ha! Someone else will have to enlighten us both. I believe it is top of the rails to the center of the knuckle, but as usual, I'm probably wrong