My Kadee Under Track Uncoupler

This project is about stopping unwanted uncouplings using the Kadee #322 between the rails magnet.  I got this screwy idea of mechanically lowering the 322 so that it wouldn't accidentally uncouple the Kadee couplers.

I had purchased several Lambert Associates solenoid type switch machines several years ago and they've just been sitting in boxes so now its time to put one of them to work.

The first thing was to do a bit of prep to see if it was doable.  I cut up a small section of Atlas Code 83 track to experiment with.

 It looked doable so next up is to manufacture a box to hold the moving magnet.

 I built a housing from Styrene and used a steel
rod in a brass tube bushing inside a Styrene tube to push for the mechanism to move the  magnet.  Using the Styrene tube to sleeve the brass tube made the mount very strong, brass to Styrene doesn't cut the mustard for strength. 

The movement needed is 5/32”, the same amount of movement as an HO turnout so a
standard switch machine works great.

I began by gluing two layers of 0.04” Styrene to the bottom of the magnet.  Then I used 0.020” sheet Styrene for the inner walls and sandwiched that with 0.04” for the outer walls to end up with a rectangular housing.  I went with 0.01” clearance around the magnet.  The housing is 1⅛” deep with three layers of 0.04” sandwiched for the pit bottom at ⅜”
deep.  ⅜” below the layered bottom is a 0.04” housing bottom plate.

The housing turned out very strong.  I left a .125” sleeve of the 0.02” inner wall to frame the opening between the rails.

I drilled a hole in the center of the layered Styrene base and used plastic cement after inserting the Styrene tube with the 1/16" K&S brass tube as a sleeve for the 0.04” steel rod that will move the Kadee magnet.

I glued the magnet to two layers of .040" Styrene so that I could drill a hole for the .040" steel lift rod, I didn't want to disturb the magnet.

Recessed, no uncoupling.

Raised for uncoupling.

I used a drop of CA on the push rod to secure a small 1/16" tube so that the switch machine push mechanism can lift the magnet into the uncoupling position.

I attached .040" Styrene sheet below the housing to hold the switch machine to operate the magnet lift rod.  The Lambert Associates switch machine has plenty of power to raise the magnet.

I made the fit between the switch machine lever and the push rod sloppy so that there is no friction, the magnet uses its weight to recess.

I've had this uncoulper working for about two months and it has worked extremely well.