Kadees on Berwicks

After putting it off for years (literally) I've finally started making good progress converting the rest of my O scale rolling stock to Kadee couplers, specifically 805 metal couplers in the 817 plastic boxes - what would now be a #816.  Progress has been so good, in fact, that I've run out of the plastic boxes I had left.  I ordered more which should be at the local hobby shop this weekend, so in the meantime I'm writing this blog post about putting Kadees on Atlas O 60' Berwick high cube box cars.

Not all the Atlas couplers are the same length, so the first thing I did was to measure the distance from the end of the car to the outside face of the Atlas coupler knuckle, to make sure I got the Kadee mounted in the same general place.  It turns out the in the case of the Berwicks at least, the holes are in the right place so just re-using them puts the Kadee coupler knuckle face exactly the same distance from the end of the car.  But you can't tell that right off, the first problem is removing the Atlas coupler.

The Atlas couplers are held on with two screws that are inside the coupler box - you have to pop the lid off and remove the spring and coupler to get at them.  Popping the lid off an Atlas coupler box without breaking anything is a real challenge.  Someone once posted a picture of a tool they came up with that makes it easy, I wish I could remember who or find the post so I could give credit, but I can't.  However I was able to remember what the tool looked like, so I made one by cutting a few pieces of 1/16 thick brass, filing the end of one into shape, and soldering together the sandwich with a resistance rig.  Here's the tool in action.

Coupler box tool

Basically, you slip a knife blade in under the cover and exert a little pressure, pull the tab back with the tool, and once you get it pulled back far enough the lid will pop off.

Popping the cover off

Once you've got the Atlas coupler box off you'll notice that the screws are very different lengths.  This is important - the screw that goes in right at the end of the car has to be shorter, because it goes into the little spacer block right over the plastic end of the car.

The spacer block under the coupler box

This is the time to put the car back on the track and use the body height end of the Kadee coupler height gauge to see whether and spacers are needed.  I use Micro-Mark coupler shims.  In the case of the Berwicks, 1 shim is needed.

By comparing the length that stuck out of the Atlas box against different length screws sticking out of the Kadee box & 1 spacer combo, I decided an 8mm screw was about right for the end hole, and the other hole I wanted more bite so I used a 10mm screw. I bought my screws from NWSL - my packages say 31208-5 for the 2.0x 8mm panhead screws, and 31210-5 for the 2.0 x 10mm panheads.  The Atlas couplers are held on with 2.0 mm metric screws, spaced very slightly closer together than the Kadee holes.  By using the same screw size, and enlarging the holes in the Kadee box with a #43 drill I find I can re-use the same holes.

Next step is to prepare the coupler.  With a metal coupler in a plastic box most of the tedious filing and burnishing that's needed with an all metal installation is unnecessary.  All I do is burnish the outside of the knuckle with Kadee greasem, since it's the part that needs to slide by another coupler really easily to couple slowly.

Burnishing the knuckle

And more burnishing just to be sure

It's not that hard to burnish the knuckle faces on an installed coupler, but it's trivial before you put the coupler in it's box so I like to do a thorough job of it.

Then put the coupler together, get the coupler, spacer, and screws all sandwiched up, and mount it.

All the pieces

Putting in the center screw (that goes over the car end) first since it's the shorty makes sure it gets as much of a bite as it can, and of course you have to be careful not to over tighten it.  The other screw will be a little reluctant to find the hole (even after enlarging the holes the spacing isn't a perfect match), but by tipping it a little it will catch and you can then straighten it out.  No need to worry about over tightening the 10mm screw, at least not with a jewelers screw driver.

Installed Kadee

The end result sticks out the right amount, is the right height, and works great.  The Tighe warehouse at the back of my layout (track center line 26" from the layout edge) is the industry the Berwicks head to on my layout.  Uncoupling the Atlas couplers back there can be pretty annoying - visiting friends have sometimes been unable to do it at all.  The switch to Kadees has improved the experience immensely.

Now if those plastic boxes would just come in so I can finish off my Berwicks and get on to the coalveyors...