Re: The new couplers

Doug Cummings

If there have been various discussions I have missed them. I do not read all of the modelling magazines that exist. And I am sure there others in the same boat. There are people who model and make a science of it, and others who model as a hobby.  I model because I have always liked trains and worked in the industry for a good many years. 

There has already been some discussion on the new Kadee 705 Hon3 coupler

Here are some salient points on them:

FIRST AND FOREMOST! The 705 coupler is NOT a drop in replacement for a 714 coupler!

Kadee says that the 705 and its box will go anywhere a 714 and its box will go.

The 705 will mate readily with the Kadee 714 and the Sergent Sharon Type true to scale coupler.

The 705's are an all metal coupler in a plastic box.

The width of the 705 box is more or less identical to the 714 box.

Due to the 705's pivot design, the coupler must be used in the box that was designed for.

The 705 shank thickness behind the knuckle is thinner than the shank behind the knuckle of the 714. This means that the 705 coupler box front opening is not as tall as the 714's front opening. This also means that if you try to put a 705 in a 714 coupler box. The 714 box needs to be modified in some way so that the 705 won't flop around vertically in a 714 box.

Even though the pivot hole in the 705 is roughly the same width as a 714's coupler box pivot post (or 714 clone boxes on car kits). The 705's pivot hole is arrow shaped, not round.

In order to mount the 705 coupler on Rail Line, PSC, Durango Press, Model RR General Store and Blackstone cars. If you do it the way Kadee suggests. Most of the Kadee 714 clone coupler box and the pivot post must be removed from these cars.

My experiments with the 705 couplers thus far show that the only way to get them in a car with a 714 clone coupler box without massive amounts of plastic or die-cast removal from said car is to:

(1) Remove and throw away the 705 coupler box lid.

(2) Remove the coupler and its centering spring from the 705 coupler box and set aside.

(3) Trim off the side walls of the 705 box floor flush with the insides of those walls. DO NOT REMOVE THE REAR WALL! This wall is the same height as the pivot post and will give you a second contact point when the coupler box is screwed to the bottom of the car. It will help to keep the box from compressing. The 705 coupler box floor with its pivot post is now almost exactly the same width as the 714 clone coupler box area on the car you are converting. You might need to do some filing to it to get a perfect fit.

(4) Remove the clone pivot post on the car that you are converting to the 705 coupler.

(5) Reassemble the 705 coupler with its centering spring on its pivot post and flip it over.  

(6) Place the 705 coupler with its floor in the coupler box opening on the car and slip it forwards or backwards until you have the spacing between the back of the 705 coupler knuckle and the coupler buffer plate that you want.

(7) Mark a center spot in the mounting hole of the coupler and drill and tap for the 00/90 screw supplied by Kadee and screw it in place.

Note: The pivot hole on Blackstone cars appears to already be a 00/90 thread and pretty close to the best position possible.

I have no experiments or intentions of mounting the 705 on a locomotive pilot. The Sergent Sharon type pilot coupler is the best coupler for this as far as I am concerned.

This may seem like a lot of work. But on thing is for sure. The new 705 coupler gets rid of the 714 slinky effect in trains! 

I hope this helps

Dale B  

On Thu, Jul 25, 2019 at 2:26 PM Doug Cummings <dougcummings@...> wrote:
I was down at my local hobby shop today and asked about the new couplers. Quite surprising, I was advised it is not a one size fits all situation. It was told it also depends on the make and model of the car.

So before I go out and buy dozens of these new couplers I think we need a lesson on which make and model of coupler applies to which make and model of car. I would hate to buy a dozen couplers only to find they are not the right ones

Is before investing in a batch of new couplers can some explain the situation and what couplers fit what cars, etc. etc. etc.


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