Body Mount Couplers for Atlas Tank Cars

[cbroughton67]

@Cajonpassfan The outside dimensions are 3/16" x 3/32" rectangular brass tube.

[bbussey]

@Cajonpassfan The outside dimensions are 3/16" x 3/32" rectangular brass tube.

Looks like a truck upgrade is in order as well.  Now that the couplers are neatly body-mounted. shouldn't this prototype be on 100-ton trucks with 36" wheels?

Another tidbit — if you can get your hands on them, the BLI MTL clone couplers have the AccuMate-style design inside the box, so this setup will work with them as well as provide an MTL-style coupler.

[nkalanaga]

I have also used the brass tubing, and it makes a stronger box.  However, some Accumates are thinner than the inside of the tubing, and need a 0.005 inch shim to keep them level.  Depending on the exact mounting height, the shim may be above or below the coupler.

Bryan:  The BLI couplers sound ideal.  Are they available in quantity, or are they only a "service" part, in limited supply?

[cbroughton67]

Looks like a truck upgrade is in order as well.  Now that the couplers are neatly body-mounted. shouldn't this prototype be on 100-ton trucks with 36" wheels?

Those are FVM 36" wheels in the photo. I'm 99% sure those are 100-ton trucks as well.

[Missaberoad]

Looks like a truck upgrade is in order as well.  Now that the couplers are neatly body-mounted. shouldn't this prototype be on 100-ton trucks with 36" wheels?
Another tidbit — if you can get your hands on them, the BLI MTL clone couplers have the AccuMate-style design inside the box, so this setup will work with them as well as provide an MTL-style coupler.

Those are FVM 36" wheels in the photo. I'm 99% sure those are 100-ton trucks as well.

Agreed they are Atlas 100ton Barber S-2 trucks...

[bbussey]

I have also used the brass tubing, and it makes a stronger box.  However, some Accumates are thinner than the inside of the tubing, and need a 0.005 inch shim to keep them level.  Depending on the exact mounting height, the shim may be above or below the coupler.

Bryan:  The BLI couplers sound ideal.  Are they available in quantity, or are they only a "service" part, in limited supply?

Unfortunately only as a service part.  But it's possible to pry a couple of pair if you call and plead. 

[nkalanaga]

Not worth the trouble, since I was thinking of cushion underframes, and I would need a lot of them.  The original reason for using Accumates was that they were free, I had to cut the truck mounted ones off anyway, and it seemed easier than mounting 1025s on a brass strip, which I had been doing for many years.

[Cajonpassfan]

@Cajonpassfan The outside dimensions are 3/16" x 3/32" rectangular brass tube.

Thanks much Chris, got to try that!
Otto K.

[bbussey]

Well, I got the test parts yesterday. Pulled them from the Bestine soak a few minutes ago. Other than me designing the offset brakewheel footprint clearance on the wrong side, it looks great! 

The coupler pivot post must be threaded carefully with a #00-90 tap and doesn't need to be drilled out first. The tank-mounting hole must be drilled using the coupler box as a guide. The back screw is what secures the coupler box to the model. You will need to shave the lip off the bolsters to lower the car to a better ride height. You will need 1015 couplers and box lids. I also recommend dipping in Neolube to get color and to lubricate the box interior.

I'm going to correct the solid model and re-submit for the next test shots.

[bbussey]

Correction — I mirrored the parts around the sprue, so only half of them are bad. Will attempt to equip a car and post photos later this evening.

[bbussey]

It didn't take long to do. A couple of minor modifications to make, as the tolerance is too tight in a couple of areas and won't allow for manufacturing variations in the model. The coupler also is a tad too high to remain on the included Atlas trucks in conjunction with shaving the bolster lips, which was my goal.  I have to test with an unmodified bolster and BLMA or Atlas PS-1 Barber trucks. Other than that, the concept will work.

[bbussey]

By the way, you can lower this Atlas tank simply by shaving the bolster lip. The truck-mounted coupler box still clears the bottom of the deck, albeit with a paper-thin margin.

[bbussey]

Shapeways finally has shipped the latest revision of the coupler pocket.  I should have them on Monday.  Next report with photos will be Tuesday or Wednesday.

By the way, mounting the tank on ex-BLMA or Atlas Barber S-2 trucks (from the new PS-1) with unmodified bolsters puts the car at the same height as riding on the original trucks with shaved bolsters.  If you use the ex-BLMA ASF A-3 friction-bearing trucks, their scale width will improve the look of the car, so that might be the best option.  The Atlas Barber S-2 would work also, but they are a little old for the prototype I believe.

[bbussey]

I think we have a winner. I need to make one minor modification and then it's ready to go. This tank is riding on Atlas Barber S-2 trucks (the trucks on the PS-1) with unmodified bolsters. This configuration also will work with the two ex-BLMA trucks with 33" wheels. It also works with the Atlas trucks supplied with the model if the embossed ring on the truck bolsters is shaved.

The MTL 1015 coupler guts and box lid are required, as are a flathead #00-90 (to secure the box lid to the pocket) and round head #00-90 (to secure the pocket to the tank body).  I used 1/8" screws but longer screws can be cut to length. I also redesigned the back end to eliminate any open air between the bolster and car end to give the appearance of a full car length centersill.

I will have this ready by Monday. 

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[ai5629]

A question for you Bryan.  Does the screw that attaches the pocket to the tank car body hit anything on the way in when you attach it?  I was looking at the parts diagram on the Atlas website for the 11k tank car, and there is a large steel weight that sits in the lower half of the tank body.  I did not know how far it extends towards the ends of the car, and therefore if it prevented a screw from attaching to the body.  One more thing, when are you going to make this ingenious pocket available to the masses?  Thank you.

Jeff