2-Railing a 3-Rail Atlas Boxcar

I have done it.  

The biggest problem to solve is mounting the truck to the body.    There are two issues.     First Atlas builds to their own standards not the NMRA standard. The NMRA has standards and reccommended practices for the height of the truck bolster from the rails, and the height of the bottom of the car body from the rails.  The height of the Atlas truck bolsters off the track is higher than the Athearn truck.   The Athearn truck is built to NMRA standards.   And the body bolster is much thinner.    Therefore you most come up with a spacer to keep the car body at the right height, or replace the bolster on the car body.   

The second issue is that the way Atlas mounts the trucks.   the kingpin is much larger than the hole in the Athearn truck bolster.    The screw for mounting the Atlas truck to the body which works great in their bolster, is too big for the Athearn bolster.    The shouldered screw has to be replaced.

I have not tried replacing the Atlas bolsters on the body but that might be a simpler project.

This is not that bad just frustrating.    And when I was done, the car tended to lean to one side because of my spacers.   I had to fiddle with that for awhile too.   

Ed

I turn a bushing that fits over the Atlas post to bring the height down to NMRA spec and then use a longer metric screw to tread into the Atlas post.  My truck preference is Intermountain over Athearn as I like the way the brake shoes and plastic springs look when weathered. 

As far as couplers I'm disappointed with AtlasO's latest "Kadee clone".  By my count this is the 5th or 6th iteration of Atlas scale couplers and they still don't have it right.  While the contours of the latest coupler match the old Kadee 805, the tension on both the knuckle and shank springs are is too stiff to provide smooth operation.  

In a better O scale world Kadee would offer a special AtlasO retrofit coupler in their 700 series with pockets sized for mounting to Atlas under frames - a thick top surface to provide the correct height without shimming, internal counter sunk mounting screw hole locations  matching Atlas's for correct set back from the end sill, and a single counter sunk flat head coupler pocket lid mounting screw (I hate Atlas's "snap off lids" as they  require too much force). 

Ed Rappe  

Jim and Ed,

Thanks for the help.

Ed, what is the height difference between the Atlas bolster and the NMRA standard?

Thanks again,

Ed

Ed,

I am not sure on the height, Ed Rappe probably has a better nuumber but my memory tells me it was quite large, maybe .125 inches (1/8 inch).   I tink I used a flat rubber plumbing washer.

Jim

Ed Rappe,

In a better world, Atlas would not have designed their underbodies so the coupler mounting holes are not the same as Atlas.    They designed theirs when Kadees were available and common and could easily have made their mounting holes compatible at no difference in cost.    They  were just playing the toy-train game where you try to make it difficult to mix in other mfgs products.    This is my opinion anway.    I  think that all the toy-train mfg use a business model where they try to get the customer to use only their products by buiding in some incompatibilites.   It makes sense to some extent for them as long they don't alienate customers.   They want you to buy only thier cars, locos, track, switches etc and stay away from other brands.

Ed and Jim,

Jim, thanks for the measurement.  .125" sounds large but totally believable.

If Atlas HO used the same alleged tactics as Atlas O, Atlas HO would have been out of business in a fortnight.  It is a shame that Atlas O does not respect the O scale buyer and has to resort to such alleged tactics.  Just my opinion, of course.

Ed

I've done the conversion and it's just as Ed describes. Add a spacer for proper ride height and open up the truck bolster hole as necessary for fitment. it's important the truck bolster has a stable bearing surface to prevent wobbling

a number of Atlas cars have a diecast underbody or body bolsters that are best not modified.

Ed

I use a small lathe to turn my adapter bushings.  Since I turn the bushings to slide over the existing Atlas one and sit against the frame each tends to be slightly different depending on the car.  A digital caliper makes the task of calculating the bushing size relatively easy.  First measure the height of the existing AtlasO body mount off the frame around its base. Then measure the bolster height of both the AtlasO truck and the one you want to replace it with.  The bushing needs to be cut to a thickness equal to the first measurement plus the difference between the two trucks. 

With regard to the AtlasO coupler, one needs to go back to the early 1970's  Atlas/Roco product line.  Atlas lead the way with introducing mass produced plastic sale dimensioned freight cars to O scale. (I discount the AHM/Rivarossi product line as they didn't offer scale couplers).  At that time Kadee didn't have the dominant presence in the O scale market that it later gained.  The Atlas coupler copied the head of the Central Loco Works magnetic coupler (with permission of Bob Smith) but with an Atlas patented coupler pocket. When Atlas re-entered O scale around 1990 after a 15 year lapse they reused their old scale coupler design (but not as well made!).  In retrospect we'd all be better off if when AtlasO/China created new tooling they adapted NMRA bolster and Kadee coupler pocket practices as Weaver Models did when they entered the mass produced O scale market.  With their existing inventory of tooling for dozens of models it's probably not practical for AtlasO to change now.  But with tens of thousands of AtlasO cars running around with substandard scale couplers, I think Kadee might find an attractive market for a tailored product.

Ed Rappe