Atlas 90 ton hoppers

[Andy_S]

Hi folks,

I was wondering if anyone has converted the atlas 90 ton coal hopper to body mount couplers? If so could you explain how and maybe post some pics?
Also has anyone updated the trucks?

Thank you!

Andy

[nkalanaga]

Body mount couplers are easy.  No pictures, but none are really needed.

Remove the trucks.

Take a chisel-blade knife, lay it flat on the bottom of the end sill, and push it into the body bolster.  Don't remove any material, just make a shallow cut.

Put your chosen replacement truck on.  I've used the early KD/MT roller bearing trucks on most of my cars, as that was what was available when I bought them years ago.  A couple have MDC roller bearings, but those are long out of production.  These cars SHOULD have 100-ton trucks, but you'll have to check the ride height with any of those you install.

With the trucks on, check the end sill height against the mounting height for your chosen coupler.  Measure the difference and find a strip of styrene that thick.  If it's 0.015 or thicker you're good to go.

If your trucks sit low enough. you'll need to do a little extra work.  In any case, make a second cut below (towards the truck) from the first one, to match the thickness of your shim.  If that shim is less than 0.015 inches, make a third cut 0.030 ABOVE the first one, towards the top of the car.  Carefully cut a flat-backed notch connecting these cuts.

Cut your shim to fit from the outside of the end sill to the back of the notch.  The easy way is to cut it too long and trim the end later.  I usually use a piece of 3/16 inch strip, to match the 1025 couplers I prefer, but the width is up to you.  If you needed the extra piece, cut it from 0.030 strip the same width, to fit BETWEEN the inside of the end sill and the bolster.  If used, it should be a tight fit, to make sure it glues solidly.  Jam it in place, making sure it's straight and horizontal, then add the shim OVER the end sill and into the slot. 

Once all of the glue is dry, drill and tap for your coupler, paint the entire assembly, and mount the couplers.  Install your trucks and check the coupler height.

If you want extra braces and other details they can easily be added during the process.

It doesn't really take much work, but sounds rather complicated.  It would be nice of Atlas would make a casting to fill the gap, but until they do, this works fine.

[Andy_S]

Thank you for the info sir!

Yes it does sound complicated, maybe even a bit daunting. But its a job that needs to be done. Just so I am understanding correctly; the cut made into the bolster is for the shim correct?

As far as trucks go Id like to standardize on one. The BLMA trucks will not work; is that correct?

Thank you!

Andy

[nkalanaga]

Yes, the cut is for the shim.  All it does is make a notch for the end to fit in, rather than being butt-glued to the bolster.  That way, the joint is much less likely to break when you're drilling, tapping, and inserting the screw.  You COULD file a notch in the end of the shim to match the outside of the bolster, but that's even more work, and makes a weaker joint.

I have no idea if the BLMA trucks would work, but they would lower the car, which would affect the shim thickness.  If the car seems to sit too high, that might be a good thing, so you can try them.  If you like the current height, there's no reason you can't use BLMA trucks with a washer.  The only problem I see with true 100-ton trucks is that they have a longer wheelbase, which MAY interfere with the slope sheets, especially on sharp curves.  I haven't tried it so don't know about that. 

If you could find IM's 100-ton trucks they'd work fine, as their bolster is at the "standard" height used by Atlas and MT.  I haven't been able to find any of them for over a year.

[learmoia]

I recall someone (Brian B.)?  stating that the Micro-Trains hopper bracing detail drops into the Atlas 90 Ton Flat with very little modification.. (This part adds bracing detail, air cylinder and doubles as the mounting pad for the coupler.)  (This would take the place of the "shim")

I have the parts but I haven't sat down and tried it.

I like the notch in the bolster idea to secure the detail part on the back end.

~Ian