Body mounting KDs to old AHM boxcars

Model Railroader General Discussion (Model Railroader)
1

Actually I have stock cars but I am guessing they have the same underside as the boxcars. I wanted to build a small fleet of stock cars on the cheap and found a lot of AHM cars on ebay. I figured correctly I would need to add weight. I also knew I would have to replace the plastic wheels with the oversized flanges. I thought it would be a simple matter to cut off the truck mounted couplers and attach the KD coupler boxes to the body. I’ve run into two problems. The metal weight prevents screwing the coupler box to the underside of the car. It needs to be glued in place. Even then, the coupler is way to low. Almost a full coupler height too low. The coupler pins drag along the ties. I could put washers between the truck and the underside of the car to raise up the car body but that likely will cause excessive wobble and I’m not sure the pin would hold the truck in place if I did that.

Has anyone done a conversion such as this for the AHM box/stock cars and how did you go about it?

2

Is the fundamental problem the weight in the car that keeps you from properly mounting the coupler box with a screw? A 2-56 tap can fix that. Otherwise, you may need to cut off some plastic to allow the box to be either glued or screwed on a bit higher.

You’re right, though. It’s important to properly align your couplers.

3

You could remove the body wieght (from the car entirely or cut the wieght smaller) and inside the car put te stick on wieghts. That would allow you to use some styrene pieces to build a mount.

Kadee also make lowset and high set couplers. Meaning the coupler head is set high or low on the shaft to make large adjustments like what you need. Then only one or two spacers needed to lift the body off the truck.

Shane

4

You drill or file the metal weight to create room for a Kadee snap coupler box. I’ve done a lot of these and it’s not as hard as it looks. Kadee also makes narrow snap coupler boxes and short snap coupler boxes. If Kadee doesn’t make something that fits your model it’s probably junk.

If filing isn’t the correct answer then the weight can be drilled and tapped both for a Kadee coupler box and for trucks.

Kadee sells convenient drill and tap sets for pretty good pricing.

Kadee and others sell undershank couplers to address coupler height.

Also, don’t overlook fitting Kadee tago truck mount couplers. They work fine. I’ve even squeezed in Kadee #148 whisker couplers into some trucks or body mount coupler boxes the old faithful #5 won’t fit.

5

Hi John, yes I actually have converted AHM cars to Kadee trucks and couplers.

  1. I do not use the steel weights. Those hit the trash, and are replaced with weights I cut from 1/16" and 1/32" sheet lead.

  2. I cut away they ends of the car subfloors and build new ends from 0.100" sheet styrene. The 0.100" thickness is substantial enough to drill and tap for a 2-56 screw to hold the kadee coupler box. The sheet styrene also gives you a flat surface to mount the coupler box. I glue the sheet styrene directly to the remaining floor section, which raises the coupler box. You will also need to remove some material from the body to clear the coupler box.

  3. For these cars I use a Kadee #148 coupler in a #262 box. The #262 box is narrower than a standard 232 box, and looks better on these cars where you remove the material from the body for clearance.

  4. You can try using Kadee wheels in the AHM trucks, but I install Kadee #500 sprung trucks. I need to cement a solid styrene rod into the old truck bolster, then file it flat, drill and tap for a 2-56 screw.

I hope this made sense.I do not have any pictures of a converted AHM car project. Sorry for that.

This is a thread I wrote about how to improve an Athearn Blue Box Kit, and many of the techniques I use are similar.

-Kevin

6

They might be old but these two threads from George are still relevant.

https://cs.trains.com/mrr/f/88/t/194011.aspx

https://cs.trains.com/mrr/f/88/t/194274.aspx#2121353

Cheers, the Bear.[:)]

7

I picked up a couple of AHM stockcars for a couple of bucks years ago, but as best I can recall, neither of them had trucks or couplers. If they did have truck mounted couplers, I likely tossed them in the garbage, but later learned that it’s quite easy to remove the couplers and retain the trucks. If you wish to keep the trucks, they’re not all that difficult to convert to screw-mounting, rather than clip-ins.

I added body-mounted Kadees, attached to the floor with screws, and likewise for the trucks, which are likely from Athearn. The floor is plastic, with a sheet of lead atop it, fixed in place with two screws driven through the lead and into the plastic centresill.

I cemented some strip styrene to the inside of the car’s sides at mid-height, then added the steel weight beneath them, securing it in place using more strip styrene - the cars represent double-decked prototypes.

To body-mount the couplers, I used a utility knife to remove a bit of the lead sheet where the screws holding the couplers in place were to be located, as shown below…

I added a few details, but the cars are actually rendered quite nicely.

Wayne

8

The problem with mounting with a screw is that there is a car length metal weight that sits directly on top of the plastic car bottom which means the screw can go in no further than the thickness of the plastic bottom which is thinner than what is typically seen on today’s rolling stock. That means the screw won’t have much bite. Even if I could get a screw to hold, the coupler will set too low. To raise it up, I would have to put washers between the truck and the car bottom and if I add that much height, I’m guessing the car would become quite wobbly. If seems to me I would need to cut a space out of each end of the car bottom for the coupler box to set in but then what do I atttach it to? The coupler box would then be right against the metal weight.

9

That looks interesting but I don’t think the metal weight on my cars are lead. It is quite rigid and not a malleable like lead. I don’t think I could cut it with a uti

10

I like your idea better than what I wrote. If need be the le

11

The factory weights are ordinary mild steel. They look plated. Drilling or filing removes the plating however I think these are stamp cut from plated sheet so the edges are unplated anyway.

If you don’t want to drill and tap you can just drill and use a machine screw, lockwasher and nut for truck and coupler mounting. If you glue down the nut first then you can also still adjust or remove trucks and couplers without taking the car apart. Tapping the drilled holes is easier and more convenient. Holds the weight down at the same time.

12

Gidday John, in those circumstances, I use a 2-56 tap.
https://www.kadee.com/ho-scale-tools-and-accessories-c-274_282_316/246-tap-256-and-drills-50-and-43-p-333.htm

Cheers, the Bear.[:)]

13

Thanks Bear, I was just going to look up those links

14

It is a while since I attached Kadees to an old AHM or similar car. I recall having to chisel away a bit of cast on underframe detail so that the Kadee draft gear would have a nice flat surface and be at the right height. Easy enough to do.

Early on I just used to cement the Kadee draft gear box to the floor. That definitely needs a flat surface on the floor to match the flat surface of the draft gear box.

As far as the steel weights go, more often that not I too would remove the steel and use sheet lead. Another option would be to keep the AHM steel weight but detach it from the floor (I seem to recall it looked like they used a soldering iron to melt a plastic tab so that it would hold the weight in place) and use thick double sided tape. If you leave a gap in the tape at the ends that should give you enough space to screw in the coupler draft gear box.

The original AHM trucks are a nice enough casting I suppose but of a rather distinctive appearance. I remember finding it was difficult to locate replacement wheelsets that fit them. I definitely recall that the AHM passenger cars had cast on brake shoes that had to be shaved away if full sized 36" wheels were inserted, but with the freight car trucks I recall there was also an issue with axle ends. Curiously the one 33" wheel with RP25 flanges that I found that worked as a drop in was Train Miniature’s plastic wheelsets (which in turn I had removed from my TM of I and TM cars for metal wheelsets so I had plenty of spares sitting around.

Dave Nelson

15

I discovered that if I put a even one washer between the truck and the underside of the car, the pin isn’t long enough to hold it in place. Even if I notch out a space at the ends of the car to put the coupler box, I don’t think it is going to have the correct height.

I think I have discovered the solution. I’ve discovered the underside of Accurail’s 40 foot boxcar is a good fit for the AHM stock car. I have lots of extra unbuilt Accurail cars that I can use for these stock cars. The only thing I have to do is remove the tab that clips the shell to the underside of the stock car and that makes room for the Accurail coupler box which is part of the underside of their boxcars. Since I am going to fiddle these cars in my staging yard, I can easily swap shells if I want to put the boxcars into the mix. Since I already have more freight cars than my layout can handle, fiddling is something I was going to have to do anyway.

16

No, you definitely won’t be able to cut steel with a knife. I had removed the steel weight, re-using it as the floor for the cars’ upper deck, then added sheet lead as a weight atop the main floor…if I recall correctly, it’s cemented to the plastic floor/underbody using gelled contact cement…sticks like you-know-what to a wool blanket.

You also have options to alter the steel weight: Remove the weight from the car, then use a drill to make holes where they’re needed…I’d suggest making the holes in the steel larger than the screws that will be used to secure the Kadee coupler boxes and the car’s trucks.
You can then drill suitably-sized holes in the plastic floor for the screws used to add the trucks and couplers. In most cases, those holes will not need to be tapped in order to accept the screws, as the screws will easily cut their own threads in the soft plastic.

An alternative to drilling holes in the steel sheet in order to accommodate the Kadee couplers, you could also use a hacksaw to shorten the weight…either an equal amount from each end, or one cut at one end to remove the needed amount.

To re-install the modified steel weight, you can use contact cement, or drill a couple more holes in it, and use screws to fasten it to the plastic sub-floor.

Wayne

17

John-NYBW,

If you decide to drill the steel weight use caution,

center punch the spot where the hole is to be, put a block/peice of wood under the steel weight where the hole is going to be and clamp the weight down so if the bit catchs when going though the weight, the weight will not ride up the bit or spin around and take off a finger or two.

A ‘‘step’’ bit works very nice to do this kind of work. The deeper you go the larger the hole.

18

John, I think that you’re trying to see a more complicated way to do the conversion work, when in fact it’s very simple and basic.

It’s been over 30 years since I did the conversion to my two AHM cars, so I don’t remember exactly how the unaltered car looked, nor can I recall the actual procedure.
However, the first step should be to remove the steel weight, as it was obviously an impediment to me, too.
The photos that I’ve posted show the steel weight, unaltered, but located at a height inside the carbody, where the real car’s upper floor would have been located. If you look closely, there are small pieces of strip styrene cemented to the inside of the cars’ slats, holding the weight in place. While you can’t see them, there are similar strips of styrene above the weight…those were installed first, then the weight added, and the other strips added to effectively trap the weight in place. The weight is no longer an issue.

Look at the photo showing the car’s underbody: the Kadee draught gear boxes are screwed and glued in-place, directly on the underside of the plastic floor. I don’t recall for sure, but I may have cut excess material off both ends of the car’s centresill, in order to accommodate the coupler boxes.

If the car’s original trucks had couplers (likely horn-hook), it’s fairly easy to simply cut them off…utility knife, razor saw, etc. will take care of that.

Often, the cars with truck-mounted couplers have clip-in trucks, but it’s easy to remove the clip-in parts and alter the trucks so that they can be screw-mounted. This will offer opportunities to alter the riding height of the car, too.

To verify my suspicion that the original trucks were clip-ins, I removed one, and scraped-off the paint, as shown be

19

Another option that has not been mentioned is McHenry couplers.

I am normally all for body mounting Kadees but there are a couple of exceptions that I will cheat with and AHM cars are one of them. I do not have but about five or so but had to have the Rio Grande stockcars and since I live in Danville VA one of the Atlantic and Danville Box Cars. The end tabs that hold on the bodies and the steel weights make these things a pain to body mount plus the height is off.

The McHenry #56 is a snap in with the Talgo trucks. I added some metal wheelsets but I can not remember the manufacturer. I realize it is not as good as the body mounts and backing a string would be hard (but the weight of the metal wheels helps) but for limited use on just a few cars it has worked for me.

20

Would this be better explained by video?

shane