Kadee trouble with 21" cars

long shank couplers KD #746

@davidbross posted:

Listmates:

I built two 21" auto racks.  I can get them to work everywhere except coming out of my yard.  I have switch that goes directly into an 0-72 curve, and there is just not enough lateral movement in the couplers.  I could unscrew one side and let the boxes turn too, but then I lose the automatic centering of the couplers.  Any ideas on other approaches.

In other words, you have an "S Curve".  That is NOT a good situation for long close coupled cars. One method of increasing the swing of a regular Kadee coupler assembly, is to cut-out the sides of the gear box. If that doesn't work, then you will probably have to resort to on of those special "long shank" Kadee couplers (check their website for different styles & lengths).

Thank you both for the advice.

 I’d try modifying the boxes as mentioned. I found on my layout that was all Gargraves flex track. 21” cars had no problems negotiating even slightly tighter than 072 curves in a few spots. 072 was my minimum when it was built. The key was. The layout was built with easements into the curves. I’ve seen diagrams and formulas on how to do this. I just eyeballed them. The one spot that had an 072 curve coming off a straight portion. Instant derailment.

 Without knowing your track plan or if it;s ballasted. If modifying the boxes doesn’t work. You might be able to take out the 072 turnout and replace it with a #4. The curve won’t be so abrupt and you can maybe go slightly tighter with the curve using flex track  to get where your going.

  I recently converted a set of Lionel 21” passenger cars to Kadee #805s and test ran them on my 072 layout, which I discovered a “reverse curve” issue that caused derailing.

  Although I had a 10” straight section in between the opposing curves, It required a 15” straight to solve the problem 

Al

I have  14 plus MTH 20- series cars i would like to convert to 2 Weaver  trucks. Does someone know anybody that makes a bolster or plug that goes in that big MTH mounting hole ? I thought Atlas made some thing ?

The rule of the thumb with reverse curves is that you have a straight section the length of your longest car or locomotive between the reverse curves. Glad you got your situation resolved. 

@clem k posted:

I have  14 plus MTH 20- series cars i would like to convert to 2 Weaver  trucks. Does someone know anybody that makes a bolster or plug that goes in that big MTH mounting hole ? I thought Atlas made some thing ?

That's funny.  I want to convert my Weaver cars to MTH trucks.