Buy one of each and take a

Buy one of each and take a look. 

KD#5/148 look tons better than horn hooks and I have them on a bunch of kit built cars such as Athearn, Accurail, MDC and Walthers etc.  Yes, I have built quite a few kits over the years. 

I have bought RTR cars more recently and those which come with Kadee's, such as Intermountain, ExactRail, Tangent etc, seem to all have the "scale head" (as labled IIRC) #158 or equivalent head.

I picked up a bulk pack at close out at a train show of the "scale head" couples that have the bronze spring and installed them on a number of cars and have found I like the looks of them even more than the old #5.  They look less "oversize".

Joe commented in another topic that if they are installed properly and at the right height, #5/148 can be extremely reliable.  IIRC, he commented that the scale head can be almost as good if installed properly, very reliable.  I think only a fraction less, but because they aren't as tall (top to bottom) so a bit more susceptible to height mismatch, logically, and a bit lest gathering range.

Ultimately it's up to you.  I have both standard and scale head but have decided going foward to go all scale head.  they do operate with each other but operate best with same kind better.

my 2 cents.  Jim

My Take

I use a mixture of Kadee #148 and #158 whisker couplers (plus their equivalents with separate centering springs on older cars).  I've come to prefer the larger #148.  I use those to replace plastic couplers on models so equipped, or the Scale Trains metal couplers.  For any car that comes with Kadee 158s, I typically leave them in place.

Subjectively, the 148 seems to require a bit less force to couple, and operators have a somewhat easier time uncoupling them with skewers.

Me too

In my Run like a Dream Rolling Stock book I talk about mixing different products and how that leads to less consistent performance.

Best performance is consistently predictable performance, and you get that by minimizing variability. In other words, when it comes to wheels and couplers, pick one vendor's product you trust and STICK WITH IT. 

For me with couplers, that’s the Kadee #5 family, which for me now has become the 140 series whisker coupler. They have an excellent gathering range and can be extremely reliable if installed with a bit of care. The scale version 150 series has a smaller gathering range and are more susceptible to height variations. 

The 150 series can also be pretty reliable if installed with care and if you’re more anal about proper coupler height.

Mixing 150 series and 140 series couplers on the same layout isn’t going to get you the most flawless performance. They do work together, but you WILL have more failures with mixed couplers.

Thank you for the replies.

Jim, that is a very interesting response and sums up why I asked the question in the first place. I wondered if rolling stock makers will move toward the semi-scale couplers.
I will take your advice and try both at the beginning.
Rob, since you say they work reasonably well together, it wouldn't be necessary to step backwards and replace #158 with #148.  I am reading a lot, and can't honestly say yet what part of the hobby would give me the most pleasure. I'm reading and learning about operations and trying to think what way to go with a layout plan.
Joe, I'm reading your Run Like a Dream, Rolling Stock now, and I will definitely finish before making a big purchase of couplers and trucks!  I really appreciate your comments and know that flawless operations will make the hobby enjoyable.  I admit any derailment or uncoupling is just not enjoyable. I could see where a smaller coupler would be more likely to come apart at changes in grade.

From what I can tell, all the

Athearn et al...

Athearn uses plastic couplers because they own McHenry. Accurail likewise uses Accumate couplers for obvious reasons, and I guess they are inexpensive enough when compared to true Kadees to make them attractive to the other companies that use them. Atlas may have also used them on a limited number of cars because Accumate possessed the only scale-width draft box coupler, at least until Sergeant made his non-Kadee compatible ones. Kadee never has made a coupler to fit that format. 

The companies who use the Kadees scale head couplers tend to be the ones that offer higher end and detailed (and expensive) cars. They probably have determined that their customers, who are paying a premium price for accurate cars, are going to want the closest to scale coupler from the gold standard for such things.

As for Walthers and ScaleTrains.com (particularly Rivet Counter), who both have recently created their own metal couplers, I can only assume that they both want the cachet of having a "higher end" (metal instead of plastic) coupler, and believe they can make them reliably for cheaper than they can buy them from Kadee.

I have no inside info on this, just observation and some guesswork. 

Kadee #178

Is a scale head coupler with a narrow "scale" draft gear box.

Scott Chatfield

"For some years Walthers had

  The Walthers Proto Max couplers actually work pretty well for S scale since they are a bit over size for HO scale. ...DaveB 

I've started putting #153's

I've started putting #153's on most everything as they have a shorter shank giving closer, more prototypical coupling. #158's for cars with cushion draft gear that have more of the drawbar exposed.

Athearn uses plastic couplers

Athearn's McHenry are junk.  I once ran a 20 car (out of the box) Thrall gon train at a modular meet which were factory equipped with the older McHenry's;  the train would separate randomly because the plastic finger closure spring was no good having fatigued while in the box.  That is basically an intrinsic design defect from the factory.  Due to it, I've heard Athearn will replace them with the newer version FWIW (not much).

The McHenry's on newer release Athearn models look decent but are also junk.  They tend to jam in the open position.  I haven't run them that much and had many jams.  They are really bad.  Shame on Athearn for using them.

Athearn may save money but the McHenry's are horrible and must be replaced.  I hate to say it but horn hooks are probably more reliable.  I buy Athearn models that fit my needs despite the horrible couplers they come with.

Accurail Accumates seem to have given me less trouble than McHenry but they are the worst looking of the plastic and take more force to couple.  I believe Rob has reported operational issues.

Best practice is to toss the plastic clones as soon as possible.

Correct me if I'm wrong, but Atlas has offered some of the former BLMA freight cars with Kadee's; BLMA factory equipped their models with Kadee's.

The fly in that ointment is Athearn Genesis, who offer higher end and detailed (and yes, expensive cars) .  The street price is a bit lower than Tangent but higher than Intermountain, both equipped with scale head Kadee's.  For some reason Athearn hasn't come to the same conclusion while selling similar higher end and detailed models (Genesis).

Regardless, it's nearly universal that scale head are used in RTR cars factory equipped with Kadee's.

Walther Protomax being nearly identical clones to the Kadee #5 head seem to operate almost as well and most seem to be ok leaving them installed. 

By contrast, lots of modelers report ScaleTrains metal couplers aren't as good as Kadee's and say they replace them.  Replacing any plastic coupler, including ST, seems to be a given.

Given the overall cost of models, the cost of Kadee's seems to be a smaller and smaller fraction of the cost of a freight car and especially an engine.  It seems the benefit of factory equipping Kadee's would outweigh the small increase in cost to factory equip. 

Modelers who already know Kadee are the "gold standard" are going to absorb that cost anyway, one way or the other.  Those who don't may "pay" with unreliable beahavior and frustration.  Fortunately, we can buy Kadee's and make up for that particular deficiency from Atlas and Athearn, and Scale Trains (assuming their metal couplers are less reliable than Kadee's.

Do they seem to operate just as well as the standard shank.  The shorter shank does seem like they would improve model appearance and over a long train, may shorten the length significantly.

Accumate reliability

I'm returning from a 20-yr hiatus, still grasping the concept that no one "does" kits anymore, and thankful Accurail exists with their excellent steam-era designs.  The Accumate couplers in the kits take a bit of close-in massaging to function near the Kadee level, but I've seen it work.  Any flash at all, even a feathery wisp, will kill performance.  There is a shallow pin/cup combo on the shank halves that is critical; any flash or parting line 'cruft' in there is bad.  A light burnish of the shank faces, clean ALL facets of the pin/cup, and they should work fine.

Now, the Accumate's uncoupling pin.  That's a whole 'nother religious war I've yet to choose a side in.  

Tim B.

RTR is very popular but don't count kit builders out too quickly

Tim, I wouldn't go so far as to say no one does kits anymore.  While I do buy RTR, I still build kits, and I read about people who build kits on forums often.  You'll find the same the longer you rub elbows with model railroaders.  But even a lot of the RTR rolling stock such as Atlas and Athearn still need couplers replaced/installed and some adjustments.

You'll be pleased to know there is another company to add to steam era fans -  https://www.prototypejunction.com/

They appear to be in the early stages.

I haven't had a great deal of experience running the Accumate couplers so others who have, such as Rob Spangler, can chime in on their take.

no one does kits anymore?

   Don't worry about it. There's millions of unbuilt kits in model railroader's closets. They all eventually show up on ebay or estate auctions. Post what you want and someone is likely to have one to sell.....DaveB

Don't worry about it. There's

Very true. I see tables and tables of un-built kits at the Timonium MD train show and other smaller shows that probably have been released from their bondage in closets.  There is definitely a lot out there on the secondary market, even if not being sold in brick and mortar hobby shops anymore.

Many bought far more than they had time to build.  I looked at my stash decided I would not build all of them either and have sold most of them off, but not all.  In the past few years I've build some P2k kits, MDC ballast cars, Intermountain box cars and a others.  Now that the basement if mostly finished I am hoping to get back to the model work bench.  Lots of models to equip with Kadee's and some to build.

I use a mix

of 148s and 158s with few, if any, problems.  I have found that the smaller heads can be problematic on long cars like auto racks and pig flats, though.  The slightest vertical irregularities can cause a break-in-two, and the problem is exasperated when the cars are under a load and the drawbar flexes.  I’ve switched all (I think) of my long cars back to 148s. No interoperability problems, though.

Prototype Junction

Thanks for that link, Jim, I've bookmarked them for further research, and I'm looking forward to seeing them at Amherst.  After last year's incident, though, I'm willing to see ANYTHING at Amherst.  Let's just say I hope to not see the inside of anything medically related in Springfield this coming trip.

Back on topic:  I tossed every X2F coupler long ago, and had been installing Kadee #5s in my rolling stock when my hobby interests had to take a backseat (Desert Storm deployment and several base reassignments).  I'm now trying to make sense of the now-expanded Kadee catalog, and am pretty sure I have a handle on short-, undershot and other variations.  It's now up to me and the budget what to standardize on, since a lot of my 'stock has to interchange with others in the Free-Mo environment.  #148s might be a decent baseline going forward...

Cheers!

Tim B.

I have found that the smaller

Jeff, I remember trying to operate 89' TOFC flat cars on a modular layout and due to the uneven nature of the track accentuated by the longer cars ability to magnify mismatches in those circumstance, those cars would separate.  If I were to try it again, I'd use shelf couplers to keep the long cars from separating.

But you brought up a good point, and that is the larger #5 Kadee head is more forgiving of mismatches, which long cars are more likely to cause.

I would stick with the

I would stick with the "standard sized" Kadees, and not bother with the "semi-scale" version.

Be aware that there may be coupler height issues and you might need a "higher shank" or "lower shank", depending on the car conversions involved. Also longer or shorter shank. Kadee has a page on what fits what for many cars and engines.

For proper height (or at least what I consider proper height), I just place a credit card on the rails. The actuator on the coupler (the "curleycue") should just clear the top of the card. Works for me.

Or buy a Kadee height guage.

...

That's pretty slick.  I have lots of cards in my wallet and I always know where my wallet it...I also have a couple height gauges and I know I can't find a one of them in the next couple of hours if you asked me to go get one...

Couplers

I pretty much always use the semi-scale Kadees, most with the normal shanks.  I've tried the short shanks, but the buffer blocks tend to interfere with them, so I have gone back to standard shank.

On many steam engine applications I have found the coupler boxes are too narrow for the "standard" phosphor bronze spring, so have to use the whisker couplers, but I have found if the whiskers are trimmed back just a bit they won't "hang up" in the coupler box