MT coupler help

[mike_lawyer]

Hi everyone,

I am working on installing an MT coupler to the tender of a first run Bachmann Spectrum Consolidation.  I am having trouble tightening the screw.  If I tighten the screw to the point where the coupler box is snug, the coupler will not swing free in the box.  Any ideas on what I should do?

[Jim Costello]

I would just release the screw 1/4 turn or so until the coupler works satisfactorily and add a very small drop of AC to the screw on the inside of the tender frame.
Will stop the screw from coming loose but not enough to stop you removing it at a later date.  Other wise use a longer screw and nut.

[thomasjmdavis]

Which coupler/box did you use?

My usual recommendation on any MTL is to burnish all the parts (and check for any flash) and add the puff of their graphite lube, but I bet you've already done both.

Also, check the hole through the coupler box- run the clearance drill through to make sure there isn't any flash or debris that might cause the screw to hang up inside it-

My Consolidation has  a 2004 (I think) mounted on the tender. I am not experiencing the issue you describe.

[mike_lawyer]

I am using an MT 2004.  Not sure why, but I can't get the box snug and the coupler having a good spring back and forth in the box.  I tried another MT 2004 and had the same problem.

Not sure if it matters, but I used a cutter 00-90 tap instead of an MT 00-90 tap.  Could that have made a difference?

[BCR 570]

I have had this happen on occasion, even when using an MT tap.  It occurs sometimes when drilling into a thin surface such as a caboose or tank car end platform.  I have had occasions when the draft gear opewrates but the coupler box is rotating on the screw.  Two possible solutions when it is necessary to back off on the screw:

1.  As mentioned, apply a small dab of CA on the screw to secure it; if you ever need to remove the coupler you should be able to break the bond.

2.  Sometimes I have installed a small strip of styrene on either side of the coupler box to stop it from swivelling on the screw.


Tim

[peteski]

When a coupler box swivels too freely with the screw tightened, I simply place a very small drops of CA at each side of the coupler box and spread it along the sides.  But be careful not to use too much glue. Also don't use the extra thin CA as it can wick between the box and the mounting surface, possibly clogging the pivot hole in the box.  Regular viscosity CA works well. Put just enough to build up a small raised area around the box.  Use accelerator to set the glue fast.

[jdcolombo]

Yep.  What others said: a (very) tiny drop of THICK CA to hold the coupler.

But my technique is slightly different.  I scruff up the side of the coupler box that mates with the tender floor.  Then I get the coupler screw started, and take a toothpick with the tiniest amount of thick CA I can muster, and put a dab on the very end of the coupler box where it mates to the coupler floor.  Then tighten the screw, and then back off until the coupler swings freely.  I like this solution because if you ever need to take that coupler off, you can remove the screw (no CA on it) and use the end of a hobby knife to pop the coupler box off where it was glued.

John C.

[JoeD]

We used to sell GOO which is pretty much a contact cement.  it surprisingly works really well.  Enough flexibility so it wont sheer off and holds things pretty well.

Joe

[nkalanaga]

Seal-All from the hardware store, or sometimes Walmart.  It's sold as a contact cement and gas tank repair, and will stick almost anything together. 

In the early 1970s I even managed to glue 1025 couplers to ConCor passenger car trucks, and they held quite well.  The joints didn't look like much, but they were under the car, out of sight.

[peteski]

Walthers Goo is likely similar to what MTL used to sell, and it is still available from Walthers or many hobby shops.  Yes, that is a viable option for gluing MTL coupler boxes.