Installing scale couplers on MTH rolling stock.

they are 2mm by 8mm on their engines I believe. (if that helps at all?)

LNCNo8Brkr posted:

This may have been covered before, but it's a simple question.  I want to install kadee's on my MTH equipment.  I know the screw holes are there for installation, but am baffled by the screw size.  The screws I have are to large, and I don't have a means of measuring the proper screw size.  Can anyone tell me which screws I should us?  Thanks.

First, are you inquiring about rolling stock, or locomotives?

I also use 2mm by 8mm, on locomotives and just used these on a MTH caboose. 

I re-drill and tap the holes for 2-56 screws on all my rolling stock. 

As Joe, Clem and Ben stated above, use #2 screws.  The length may vary depending upon the thickness of the shims (if any) required to bring the Kadees to the proper height.  (Side note: I recommend that you purchase a Kadee coupler height gauge if you don't already have one!)

As you can see in the photo below of the MTH caboose I'm currently working on, the screws obviously need to be long enough to go through the Kadee box AND the shims to reach the pre-drilled mounting lugs.

Ok, I tried using the 2x56 screws, which I had in stock but they would not go in unless I opened up the holes by drilling then tapping.  It was a pain in the neck, must be an easier way.  I did manage to break the head off one screw, but the coupler box is solid.  Perhaps at some point I will go back and extract that screw.  By any chance are you guys using self tapping screws?  I did not, I just user plain machine screws.  Thanks for the input.  I did the work on the new F-7, haven't tried on the cars.

LNCNo8Brkr posted:

Ok, I tried using the 2x56 screws, which I had in stock but they would not go in unless I opened up the holes by drilling then tapping.  It was a pain in the neck, must be an easier way.

There is. I use only 1-72 machine screws to attach the Kadee gear box assembly to ALL MTH freight cars, that are equipped with Kadee mounting holes and also come with the correct mounting shim. I've never had any problems.

 I did manage to break the head off one screw, but the coupler box is solid.  Perhaps at some point I will go back and extract that screw.  By any chance are you guys using self tapping screws?  I did not, I just user plain machine screws.  Thanks for the input.  I did the work on the new F-7, haven't tried on the cars.

 

Hot Water is correct.  MTH cars that are equipped to install Kadees are tapped for 1-72 machine screws.

Atlas cars are tapped for 2mm screws.  Most modelers drill and tap for 2-56 screws or use self tapping screws for all other cars,

Bob

Ok, that does make more sense.  Now to find a source for the 1-72 screws which shouldn't be hard.  Also will go with the 2-56 self tapping screws.  Going away for a few days so won't get back to it for awhile.  Thanks again for the input.

LNCNo8Brkr posted:

Ok, that does make more sense.  Now to find a source for the 1-72 screws which shouldn't be hard.

I purchase all my various screws from Micro Fasteners, out of New Jersey. They have EXCELLENT service.

 Also will go with the 2-56 self tapping screws.

I have used #2 "sheet metal screws", i.e. self tapping, for mounting Kadees through the center hole on the Kadee gear box assy. The center hole needs to be enlarged slightly with a drill bit, then the #2 screws work just fine.

 Going away for a few days so won't get back to it for awhile.  Thanks again for the input.

RRDOC posted:

Hot Water is correct.  MTH cars that are equipped to install Kadees are tapped for 1-72 machine screws.

Atlas cars are tapped for 2mm screws.  Most modelers drill and tap for 2-56 screws or use self tapping screws for all other cars,

Regardless of what they are equipped for, chose your own personal standard(s) and use it for all of your stock - all of my brass, plastic, or resin cars have the Kadee couplers mounted using blackened 2/56 screws.  All wood cars get #0 x 3/8" wood screws.

You might as well buy a few different sized taps and matching drill bits. There will come a metal floor or pilot that requires drilling. If you are going to convert your entire fleet at some point, tools of the trade are  "must have". Like anything else there's a learning curve, but having the proper tools for the job makes like much easier  and like Joe said, don't forget the Kadee height gauge.