Switch to Kadee

Trying to use Protocraft couplers on a small switching layout. Not happy with the operation. Which Kadee would be a good replacement. No curves to worry about.
Thanks for any and all thoughts.

John -

I don’t think that anyone on the A&O has used Protocraft couplers. From our experience (David please chime in here) the original Kadee 804/805 couplers, with the external knuckle springs, switch the most reliably and gently. The newer models with internal knuckle springs seem to couple less reliably. Assuming that the cars are able to naturally align couplers according to the curves on which each sits, it is easy to couple-up without moving the stationary car with a good DCC decoder properly set up for low-speed operation.

One thing to observe is whether each car has metal truck bolsters and a metal under frame. In that case, watch out for the 805s with the metal coupler shank and box. Depending on the orientation of the wheels, a short circuit between the rails can/will develop over time as parts wear. Even after checking that all wheel sets on a car are oriented with the insulated wheels on the same side, coupling to a similar car in “reverse” can cause a short circuit from one car to the next, through the couplers, coupler boxes, under frames, trucks, then wheels.

YMMV. All the best!


Thanks Bob, using overhead for one phase of pickup prevents shorts. Even though I’m P48, the 805s sound good as operation trumps looks, imho.

Wow! Overhead wire!

Are there any photos you can share with us? I would love to learn more about your modeling.


Not sure on loading photos here, just consider me a novice in O scale, mostly complete 2x16 layout, first time hanging wire, scratch built motor based on Milwaukee Traction work equipment. Powered by two NWSL magic carpets, Atlas metal floor, and strip wood. I can only upload one image as a new guy

John, nice layout shot! Always love seeing people building models!

Attached is all of the current Kadee O scale products. Bob is correct, the old school #805 is the gold standard as far as operation goes. Very smooth and gentle. So much so that a free rolling car won’t move when coupling! On the other end of the scale, we have put a lot of stress on the #805 in use on the A&O; heavy trains, pushers on grades, and the coupler torture chamber we call the Hump Yard! The external springs periodically pop off (mostly due to uncoupling with picks) but the couplers seem bullet proof!

I’ve used several of the newer 700 series type “E” couplers, and they are as tough as the original 800 series and look better, but they don’t couple nearly as smooth as the originals. Another advantage of the 700 series is the variety of shaft lengths and offsets available.

For what it’s worth, the old Weaver plastic couplers are perfectly suited for the trashcan! Atlas couplers are a mixed bag with the earlier version being nearly worthless, and the newer version being slightly better. Both versions use a unique coupler box that doesn’t accommodate Kadees and to add injury to insult, they mount to the car with an odd screw spacing that doesn’t match the Kadee box.

O Scale Trains magazine published a very in depth O scale coupler article by Dan Pence titled “Coupler Compatibility” in the Jan/Feb 2015 issue #77. It is available at: https://shop.whiteriverproductions.com/products/ost-201501

Well I made the switch to 805s. No regrets, cars couple smoothly. Thank all of you who answered.