Atlas trucks on an MTH caboose

Just my opinion but, that seems like a lot of work to go through, when that VERY prototypically accurate UP CA-1 caboose is NOT even a good match for a Nickel Plate caboose. I thought maybe Atlas O offered a Nickel Plate caboose in the past, plus Quality Craft (no longer in business) offered a VERY nice wood kit for a correct NKP caboose.

Hot Water, I've seen several nice woodsided NKP cabooses in past catalogs from several manufacturers, but the last one I saw was an Atlas wooden center cupola from two years ago. I also have seen a run of custom MTH CA-1's done for Stockyard Express decorated in the old W&LE scheme, which is basically what I'm modeling, but post-merger. If Stockyard Express thought a CA-1 was a close enough match for them, it's certainly a close enough match for me.

Besides which, I enjoy this sort of project. Keeps me out of trouble (to some extent, anyway!). And, when I'm done, I'll have something unique.

JonnyAce posted:

Hot Water, I've seen several nice woodsided NKP cabooses in past catalogs from several manufacturers, but the last one I saw was an Atlas wooden center cupola from two years ago. I also have seen a run of custom MTH CA-1's done for Stockyard Express decorated in the old W&LE scheme, which is basically what I'm modeling, but post-merger. If Stockyard Express thought a CA-1 was a close enough match for them, it's certainly a close enough match for me.

Well, fantasy paint schemes abound in the 3-Rail "toy train" world, however the fact remains that ONLY the UP had those wood CA-1 cabooses with those distinctive trucks (the CB&Q had similar trucks on their cabooses).

Besides which, I enjoy this sort of project. Keeps me out of trouble (to some extent, anyway!). And, when I'm done, I'll have something unique.

Hot Water, I'm not denying the fact that only the UP used those specific trucks on their cabooses. I know that. This is why I'm going through the trouble to put the proper type trucks on this model, and not just repainting the existing UP trucks.

I didn't post this thread to nitpick about details, I posted it to get some advice on how to mount Atlas trucks on an MTH model.

Go to www.shapeways.com   Do a search for Atlas O. You should see some truck mounts from Gandy Dancer & Son. These were designed to replace the stock ones on the Steel reefers that were disintegrating. They should be able to screw to your MTH floor. This will give you the exact mount for the Atlas trucks. If the MTH floor and Atlas floor are close in  height from the rails. You should be good to go. I use the very same method to mount Atlas caboose trucks on Williams Brass wood sided NYC cabooses. Didn't like the trucks, mounted to far under the steps and I run Kadee's. This was a good solution.

JonnyAce, in attempt to actually answer your original question (and not provide commentary on the merits of the project that you decided to take on)...

Although I haven't worked on a MTH CA-1 caboose, I have recently installed Atlas caboose trucks on the MTH bay-window caboose pictured below.  The truck mounting presented a similar challenge to what you described above...mainly due to MTH's trucks being attached from the top-side (inside the car) rather than from below.

BEFORE...with "stock" MTH trucks:

AtlasO Caboose Trucks...

AFTER...with AtlasO trucks installed and weathered:

I tried a couple different methods of mounting the trucks with little or no success.  Then I stumbled upon a pack of Atlas screws and black plastic flanged & threaded "blind nuts" pictured below while scrounging through my box of miscellaneous screws and nuts.  I was able to make this work with the screw mounting from below, as it should on the Atlas trucks.  (Note:  I'm sure there's a proper name for this Atlas part that I'm calling a "blind nut", I just don't know what it is!)

The newer-design AtlasO caboose trucks--with the scale-thickness side frames, rotating bearing caps (on the roller-bearing style) and raised "manufacturer's" data/lettering--are REALLY nice!   So much so that I will be looking to make some more MTH-to-Atlas conversions down the road.

The problem is that I don't remember where I got those Atlas screw/blind nut combos from.  Maybe someone here will know which Atlas cars they came from and/or where to get more of them.

In doing a little bit of research, I came across various size blind nuts sold by Micro Fasteners...they also call them "T-nuts".  I purchased a pack of both 2-56 and 4-40.  The 4-40 size is pictured below.  I'm pretty sure they will do the trick in my future MTH-to-Atlas truck conversions.

I purchased 50-pc. packs of each size, so I'd be happy to send you a few of each size if you'd like to try them.  Just let me know by emailing me at the address in my profile.

Hope this helps!

Joe, that bay window crummy looks great! I may hit you up for those t-nuts.

Dave_C, I'm not sure if those bolsters will work with the chassis on this particular model, but I will definitely buy a pair and give them a shot. If they work, great! If not, I'll probably end up using them on another project.

I had thought of a solution today about using some 3/8" brass or nylon roundstock, cutting it to length (approximately 3/4") and, using a precision lathe, turning down either end to the appropriate diameter to get a nice slip fit in both the truck center and the bolster on the model, while leaving a .140" thick shoulder somewhere in the middle. Then, using the lathe again, drill the center of the adapter shaft and tap it for an appropriate machine screw, most likely a #4-40. Then I would attach the shaft to the truck with a flathead capscrew from the bottom, and the shaft to the chassis with a washer and a buttonhead capscrew from the top. (If you haven't guessed I'm a machinist by trade.)

I'm probably over-thinking this, though.

JonnyAce posted:

I'm probably over-thinking this, though.

Almost certainly.

Most MTH cars lack car bolsters (readily available from PSC or use the resin ones that I make...); just add some and you will be able to mount Atlas, Weaver, or Athearn trucks.

I have never attempted the exact swap you are......but as someone that likes to buy basket case rolling stock and adapt trucks I have on hand I modify truck mounts often.

Not having either your caboose or truck in front of me I can say only that I would modify the caboose bolster as modifying the truck mount could affect how they work.  I either grind bolsters down or add plastic stock to raise them....whatever needed to get the correct ride height.  At times I have even cut the frame and made new frame and bolsters. Whatever is needed.  Sorry not the exact info to solve your issue but the swap I have not tried yet. 

When I did my Santa Fe caboose, I took the MTH metal floor and pounded the mounting locations flat with a hammer. Then covered the holes with styrene and mounted the Atlas trucks using washers to get the lowest possible height I could. Lots of work!

Those Atlas truck adapters make the conversion a piece of cake, but I cant find then any more. They used to come with a pack of trucks, and I threw tons of them away. If only I knew......

3 of the 4 styles of resin bolsters I make for converting cars and/or scratchbuilding:

The blue is the mold release that I used to use at times.

You have to drill & tap these, but that shouldn't test anyone's skill set......

I'll try to post some photos of the chassis on this caboose later tonight. I'm fairly certain a conventional-type bolster won't work unless I mount it lengthwise instead of crosswise. The chassis has simulated I-beam bolsters running crosswise through the centerline of the mounting holes with a cutout around the hole to allow the trucks to pivot as they should. 

Upon closer inspection, it looks like I probably could mount a bolster between the I-beams, I'd just have to narrow it. 

That's silly - half the underbody framing is missing,

I'd mill the bolster space flat and add a real bolster there, and then I'd try to put the rest of the center sill back in place.

Well, the bolsters are coming. Not much else to do now until they get here. In the meantime I've been adding a few small interior detail items simply to satisfy my OCD. 

I moved the brakeman in the cupola from watching the rear of the train (and staring directly at the smokestack! Talk about goofing off on the job...) to a proper forward-facing seat in the cupola. I also modified an MTH locomotive cab figure and made him the freight conductor, and I painted the stove black instead of the sea green that the rest of the interior is painted. Interestingly enough the interiors of Nickel Plate crummies were in fact painted sea green, so that worked out in my favor. A couple other things I wanted to do include touching up the paint where the brakeman was previously seated, and setting a coffee pot on the stove, since it'll be visible from the window. Overkill? Maybe. Maybe...

I think Atlas offers both roller bearing and friction (rigid?) bearing trucks so make sure you get the right type if you buy them.

JonnyAce posted:

Overkill? Maybe. Maybe...

Not at all.....  Get yourself a coal bucket and shovel for that stove....

Interesting project... Any ideas how you will change the height of the cupola, its location, steps, extra window, and siding board width? This is going to be a tough build... but  go for it!

BTW... does your caboose hum when you put it on the track... if so beware, it will go up in smoke...

Unplug your interior lights if it does.

Mwb, that's a great idea about the stove! Now I'll have to keep an eye out for that stuff...

J Daddy, so far I have not had an MTH caboose that hummed when track power was applied, but nonetheless that's a good tip. I was considering replacing the incandescent bulbs with LEDs to cut down on amperage draw. 

And the other details you mentioned,my kitbashing skills are not anywhere near that point yet. This was just going to be a redecorating project with added detail and proper trucks.

JonnyAce posted:

Mwb, that's a great idea about the stove! Now I'll have to keep an eye out for that stuff...

No desk area or toilet/sink area.....

I may have a set of steps that are a lot closer to what you might want - changing stuff like that can really change the entire appearance of a car.

Mwb, I'd be happy to purchase a set of steps from you if you wouldn't mind looking for them. The steps on the prototype might be a bit too difficult for me to try to make.

Well folks, I got 'er done. The solution I came up with is so simple, I'm really kinda mad at myself for not coming up with it sooner.

What I ended up doing was simply tapping the center hole in the Atlas trucks for a #10-32 machine screw, then a quick trip to the hardware store for a pair of #10-32 button head screws and a pair of 1/8" thick nylon bushings to make up the height difference. By a lucky break, the head of the screw was a perfect slip fit for the counterbore in the caboose floor for the original trucks, so that actually centered the truck under the chassis. For final assembly, I put a drop of green Loctite on the screw threads, tightened them down to where it just got tight, then backed it off a quarter turn, and that gave it the nessecary clearance to pivot. From there I proceeded with final assembly and decals.

And here's a before-and-after shot. On the left is what I started with, on the right is the finished crummy.