Question About Atlas 2-Rail Trucks

That is not a spacer.    If you look closely you can see the center "tube" from the lower bolster piece sticks up level with that cross piece.  

That cross member makes the truck more rigid and stiff.    Also I think on some atlas cars have "nubbins" on one end on the under side and that cross member rides on the nubbins to keep the car level and not wobbling.

That piece also makes the truck so stiff the springs do not work.    So there is no equalization to handle bumps on the tracks.   

If you remove it, the truck will still work and equalize but if handled too roughly might come apart.    By roughly, I mean dropping it to the floor or some other rather harsh move.

To disassemble the truck, you remove the springs, then remove those screws and take that cross piece off.    Then you can slide the lower bolster piece up and remove the side frames at the wider opening in the sideframe.

Here is what master builder George Podas did to lower these trucks to the correct hight. Screws used from below, he replaced the center piece with a strip of brass. So creative! Thanks, George!

prrjim posted:

That is not a spacer.    If you look closely you can see the center "tube" from the lower bolster piece sticks up level with that cross piece.  

That cross member makes the truck more rigid and stiff.    Also I think on some atlas cars have "nubbins" on one end on the under side and that cross member rides on the nubbins to keep the car level and not wobbling.

That piece also makes the truck so stiff the springs do not work.    So there is no equalization to handle bumps on the tracks.   

If you remove it, the truck will still work and equalize but if handled too roughly might come apart.    By roughly, I mean dropping it to the floor or some other rather harsh move.

To disassemble the truck, you remove the springs, then remove those screws and take that cross piece off.    Then you can slide the lower bolster piece up and remove the side frames at the wider opening in the sideframe.

Thank you so much for your detailed response, prrjim.

I'm just starting out on my 2-rail journey. I've located 10 of a particular Atlas 3-rail freight car, from the 1970's (I think), that I really want for my 2-rail layout. 

The photo below shows the trucks from those old freight cars. I see that these trucks "snap" into the car frame, but I feel that I can modify the frame so it can accept a screw attaching the replacement truck.

Comparing the two trucks, the Atlas replacement truck … as is … would increase the height of the car body over the trucks. That is a non starter for me. So, thanks again for telling me how to modify the replacement Atlas trucks.

But, if I wanted to save money, could I just replace the wheelsets in the original trucks? Are there 2-rail wheelsets? And, in some way, I remove the 3-rail coupler from the truck? And, install a Kadee coupler onto the body? Or, is that not practical?

Again, I'm new to this stuff. And, will be buying the old freight cars this week … and then start to convert them to 2-rail.

And yup, Sarah …. those trucks are nice!

Thanks, everybody.

In the 80s when Atlas did those original cars which look pretty much like the same  upper bodies as the new train line, they offered 2 rail metal wheelsets for them as a separate purchase.    I have not seen those available in years except at a flea market once on a while.    the big flange wheels on the trucks are plastice, so they will work on 2 rail track if taller rail is used, prbably code 148 or above - (height 148 thousandths).    

Athearn wheelsets can be forced into those trucks.    the axles are bigger and a little long but most times can be made to work.

to remove the coupler, take of the clip that holds it on and then cut off or break off the coupler mount tab.    All those cars I have ever seen have holes i the  under frame for mounting Kadees.     You use 2-56 screws and nuts.    the nuts snap into the underframe and the coupler mounts with the screws.    Sometimes you have to shim the coupler box down a smidge to get the right height with the trucks y ou are using.

The new atlas trucks are made for 3 rail stuff with room for the high couplers so they put a shallow bolster on the car and a high bolster on the truck to clear the coupler.    They are not to NMRA specs for bolster height and the cars sit too high if a standard height bolster is on the carbody.     The NMRA has recommended practices or standards (not sure which) that define what the height of the bolster on the truck should be above the rail and what height above the rail the underside of the carbody should be.    Most 2-rail mfg adhere to these standards and trucks and cars are interchangable.

An athearn truck will set the car at pretty much the right height.    However as you say the mounting hole is very large for the snap-in pin.    There were plugs sold from various people at one time to fill the hole and mount regular trucks.   Not sure if anyone still makes them.    A solutionis to get a styrene (Evergreen is a common brand) tube that has an OD to fit the hole and ID to fit a screw like a 2-56 you can use to mount the truck.   

I suggest you get an NMRA standards gauge for O scale from them or a hobby shop and use it to gauge all your wheel sets and set the coupler height.    If you go by their standards, most things you buy will work without modification.   

the new atlas cars for 2 rail do sit at right coupler height, just have unique truck mounting.

Removing the cross piece and replacing the screws allows the trucks to equalize a bit. I did this with some of my 2-rail Atlas cars that would derail on uneven spots on the club layout. In situations where 2-rail cars are available, I buy the 2-rail cars; older Weaver cars get converted to Intermountain wheels and Kadees when I add the weights (I'm technically 3RS/closeted 2-railer).