Kato SD40-2 Coupler Observation

[6axlepwr]

Tonight I was designing a coupler pocket to fill the gaping hole in the pilot face. Something to represent a real coupler pocket. While making some measurements, I come to find that the distance from the pilot face to the coupler pulling face is almost prototype distance. I was fairly impressed.  It is just a tad longer, but very close. The ture prototype distance is 25". In N-scale that is 0.156" and I measred about 0.162" on the Kato coupler.

[peteski]

Tonight I was designing a coupler pocket to fill the gaping hole in the pilot face. Something to represent a real coupler pocket. While making some measurements, I come to find that the distance from the pilot face to the coupler pulling face is almost prototype distance. I was fairly impressed.  It is just a tad longer, but very close. The ture prototype distance is 25". In N-scale that is 0.156" and I measred about 0.162" on the Kato coupler.

Nice to know! Now if Kato couplers worked even half as well as MTs - I would be quite happy.  Operationally - they suck!

[6axlepwr]

I have not operated with them.

Not being sarcastic at all. I am serious. Please tell me what it is that is so bad. What is it about them that causes them to suck?

Are MT couplers the only other option for the Kato SD40-2? I do not like the spring action in them, but what about making a bushing that makes the MT coupler a solid swing without the spring?

[Leggy]

I use them and find they work perfectly fine, then again ore trains don't do much switching especially on a simple roundy round.....

[ednadolski]

What is it about them that causes them to suck?

For me, the Kato factory couplers would not always stay coupled (even to each other).  Nothing quite like having a consist split up while trying to pull a long train upgrade...

Are MT couplers the only other option for the Kato SD40-2?

I have the Lee English/Full Throttle Z couplers installed in the Kato SD40-2, with a custom-etch brass pocket: https://www.therailwire.net/forum/index.php?topic=21980.msg336974#msg336974

They install with a 00-90 screw in the same hole that the Kato coupler pivots on.   No more spontaneous uncouplings, and no MT slinky.   The etched pocket is closer to scale, which does leave a gap, but that can easily be filled with styrene.


Ed

[jagged ben]

Tonight I was designing a coupler pocket to fill the gaping hole in the pilot face. Something to represent a real coupler pocket. While making some measurements, I come to find that the distance from the pilot face to the coupler pulling face is almost prototype distance. I was fairly impressed.  It is just a tad longer, but very close. The ture prototype distance is 25". In N-scale that is 0.156" and I measred about 0.162" on the Kato coupler.

Hmmm...The Kato SD40-2s certainly have come with some different couplers over the years.  I'd be curious which version you have.

[jagged ben]

For me, the Kato factory couplers would not always stay coupled (even to each other).  Nothing quite like having a consist split up while trying to pull a long train upgrade...

Happens to me as well.  Wish I couldn't say the same thing for MTs though...

[6axlepwr]

This is interesting Ed because you sent me some LE couplers. When I get my coupler pockets in, I will see how well the LE couplers work in it. If I only have to shim above the coupler, that would be cool. If I have to redesign the coupler pocket to accept the LE couplers better, that is just fine also. Might bring the box closer to scale as well. I like the sounds of this developement.

[6axlepwr]

Hmmm...The Kato SD40-2s certainly have come with some different couplers over the years.  I'd be curious which version you have.

I have Katos latest reun of SD40-2's. The one with the underframe detailing.

[peteski]

Brian,
as others have mentioned, the biggest problem is that they have unscheduled uncoupling. Especially betwween passenger cars.  While they are closest to the prototype appearance (overall shape, from the plan view), I'm pretty sure that the problem is due to the tip of the knuckle (the part that is curled inward) is too shallow.  When there are lateral forces on the couplers while there is a slack between them, they actually come apart rather easily.  That never happens with MT couplers.  Kato couplers are also pretty much useless for automatic (magnetic) uncoupling. Some of us do use that feature. 

[peteski]

Are MT couplers the only other option for the Kato SD40-2? I do not like the spring action in them, but what about making a bushing that makes the MT coupler a solid swing without the spring?

That spring both centers the coupler and allows it to open. Without the spring the coupler will not open for properly uncoupling center itself in the pocket.