Athearn Underframes and MT couplers

[milw12]

I have a couple of Athearn 50' double door boxcars, with the cast on coupler boxes on the metal underframes. I've tried and MT 1015's don't really fit, the box is too tight vertically and there is no side-to-side swing. Short of grinding the boxes off, is there a way, or a specific MT coupler that will work?

Call me picky, but I've standardized my equipment on body mount 1015's for operational reliability and this is enough to bother me

Thanks,
Lucas

[nkalanaga]

If there is no necessary detail on the ends of the underframe, it might be easier to cut the entire end off, then replace it with a piece of styrene sheet.  That would at least give a guaranteed flat surface for mounting the new coupler.

I did that with MT's 60 ft double door boxcar, when I got my GN version.  That giant box under the end looked so hideous I cut the entire floor off and installed a 1025.  Put on a brass strip, it nicely simulated the GN's extended draft gear, and the side view is much better.  Different reason, but the same principle, and no reason it wouldn't work for you.

As for a replacement coupler in the existing box, I've never heard of a "1015 with a thinner/smaller shank", but that doesn't mean there isn't one.

[Tom L]

Your post reminded me that I had one of these I wanted to convert as well and it inspired me to go have another look at it. You indicated that you didn't want grind the box off, but I went that route and it was pretty straight forward. I clipped off what I could with a rail nipper and then used hand files to remove the rest, even with the bottom. I drilled and tapped the mounting screw hole a scale 1 1/2 feet back from the end. I am using BLMA/Atlas trucks (with a shim inside the bolster hole) and this put the coupler height very close. If using trucks that don't have the underslung bolster, you would probably need a shim for proper height.

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FWIW, prior to his I had converted it to Accumates, which drop in the existing box but have a longer shank than MT 1015s

Tom L
Wellington CO

[gbcaboose]

I am using BLMA/Atlas trucks (with a shim inside the bolster hole) and this put the coupler height very close.
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Tom,

Where did you get the circular shim in the truck? Does it come with the Atlas/BMLA trucks?

Thanks,

Mike

[garethashenden]

Tom,

Where did you get the circular shim in the truck? Does it come with the Atlas/BMLA trucks?

Thanks,

Mike

It looks like a bit of brass tube to me.

[Tom L]

It looks like a bit of brass tube to me.

Yes, its brass tube I drilled out and filed to a thinner wall thickness.

Tom L

[gbcaboose]

Thanks guys. 

Mike

[milw12]

Thanks Tom and Nick, and good discussion, that's exactly what I was looking for 

-Lucas

[dmidkiff]

What tips do you have for drilling and tapping the metal underframes? Using a pin vise with the MTL tap and drill set takes forever and is painful. I’ve taken and chucked my pinvise into a cordless drill a couple times, but that feels very dodgy...

Doug

[nickelplate759]

If it's painful you aren't using a pin-vise with a ball handle (or whatever that's called) - you are likely using a double-ended pin vise.
That said, it will still be slow.

[peteski]

When a modeler gets involved in tasks more complex than just assembling model kits, they should consider getting a small drill press.  It makes many drilling tasks so much easier (and it can also be used as an arbor press). Micro Mark sells couple (but they are pricey). 

Or look for "mini drill press" on eBay or amazon - you can find one for around $70.  It will make your life much easier.  Or you might be able to find a drill press attachment for a Dremel tool (if you have one).

[nkalanaga]

I use  my 44 year old Dremel for drilling these things.  Not as "neat" as a drill press, but a lot faster than doing it by hand. 

Holding the frame is easy - I have a piece of 1x4 with jigs for common underframes, as well as some hopper bodies.  All they are are balsa strips outlining the frame.  Drop the frame, or body, in the right spot, and drill away.  On the hoppers, the main use was for grinding clearance holes in the slope sheets for 100-ton trucks, but the idea is the same.

[dmidkiff]

Thanks for the info guys. The pain comes from having to hold the vise for so long, making very slow progress, and backing the bit or tap out every 1/2 turn or so.

I do have a Dremel and have thought about getting the drill press rig a few times. It makes sense to use that, or a mini drill press, to drill the holes out.

Is rotational speed a concern when tapping? I would think that too fast would just strip the hole and literally drill it instead of creating threads. When I used my cordless drill, I could control the speed and went very slowly. It worked well, but still awkward to do.

I guess the underlying question is  "What is the most efficient way to drill and tap holes for body mount couplers on metal underframes?"

Doug

[peteski]

Is rotational speed a concern when tapping? I would think that too fast would just strip the hole and literally drill it instead of creating threads. When I used my cordless drill, I could control the speed and went very slowly. It worked well, but still awkward to do.

I guess the underlying question is  "What is the most efficient way to drill and tap holes for body mount couplers on metal underframes?"

Doug

I never tap by chucking the tap in a drill!!
Tapping  is done by hand, with the tap held  in a pin vise using some lube in the hole being tapped. Always go in for about a turn or two, then back the tap out for about one turn, then repeat until completion.

[Tom L]

What they all said re: drilling/tapping. I learned to lube the tap after I froze one up and had to break it off in the hole. I use a little labelle loco oil.

I drill by hand but I acquired a some higher grade bits  of the same size many years ago. The MT ones work fine, but these seem to cut with less pressure. I'm down to my last one, so might look at getting some more.

I have a double chuck pin vise that doesn't work well on harder/thicker metal. I wrap the palm of my hand with tape so it doesn't dig in! I Really need to upgrade. A small drill press would be very useful. I should have got one last year before I converted all my cars to body mounts (120 or so)!

Tom L
Wellington CO