Adventures in prototypical True-Scale coupler pockets.

[wcfn100]

So I have a 20 pair offering of the standard MTL True Scale Coupler Pocket up at Shapeways.

https://www.shapeways.com/product/BCWNJBN4P/20-pair-standard-pockets-for-true-scale-coupler?key=6cb927743a592cd44cb5d3191dc9c14d

It's only in FXD for now because it's only a few dollars more and I think less resolution lines are a real good thing for this product. There's a $1 markup to go directly to printing other pockets as we go forward.

Don't go nuts yet.  There's still a lot to figure out with all the types of cars out there.  But if you do order any, please post your experiences good or bad.  I'll post more installation information in a few days.  Maybe Tom will let me have a sticky with the coupler modification and the measurements of where to drill the mounting hole and also the recommended height to the top of the coupler box.

Remember that you will need some 00-90 flat head screws for this particular pocket and you should have an 00-90 drill and tap.  Also, it's in the notes at Shapeways, but I've only tested these for 40' (or so) cars on a 15" radius (no easements) and 13.7" radius with a small 19" easement.  I'm very interested in any testing done by others.  I should have a couple other sizes ready to go in a week or two.

If you've been interested in the Atlas ore car adapter, speak up, I'll put those up too.

Thanks,

Jason

[robert3985]

Jason @wcfn100 , I just ordered 2 sets of 20 (40) of these!  I've been twiddling my thumbs waiting for this, so thanks! 

I don't have radius problems as my minimum radius is 24" and my mainline turnouts are #8's minimum.  Branchline minimum radius is 18" with #6 turnouts being the minimum.  Since I'm modeling what ran between Ogden and Wahsatch Utah a decade prior to 1957, my longest cars are in my passenger trains. 

I am anticipating good things with the MTL True Scale couplers and your "standard" coupler pocket!

Once again, THANK YOU!

Cheerio!
Bob Gilmore

[ednadolski]

Ordered mine!   Really looking forward to trying these, thanks for making them available! 

I will be trying these out on autoracks and 73' centerbeams, but my minimum curve is 24".

Ed

[wcfn100]

Thanks guys.  I really look forward to any input you may have and to see what you think of the coupler operation with the modified coupler.


Jason

[Ken Ford]

I just ordered some, too.

[Ken Ford]

I think we're to the point that a coupler height gauge for these would be useful... hint, hint.

[wcfn100]

Ken, a coupler gauge was on the list but I didn't follow through. Here's where I'm at with that -

I'm not trying to put myself in a situation where I'm dictating coupler height.  I'm a guy that wishes freight cars didn't come with couplers, trucks or wheelsets.  Those should be a separate item of the modelers choosing and to be set however he/she sees fit.  However, I am designing these using the .216" that MTL claims their regular coupler centerline is.  That measurement goes with the 2' 10-1/2" prototype measurement from every freight car drawing I have.

One other issue is accuracy of the print.  I wouldn't make a gauge out of FUD/FXD because of how brittle it is and don't have a ton of experience with other materials.  I know something like HDA can render well off the specified dimension.  There's also the roughness of some of the material.  This might all be trivial, but with the size of the couplers, I think the more accuracy the better.

The bottom line is I'm more comfortable if people made their own gauge.  It's really easy if you have a caliper to fashion one from styrene.  I can certainly provide the specs I'm using.  But if you want to be a guinea pig, I can draw something up probably today and leave all the printing material options open for you to choose.


Jason

[Ken Ford]

Jason, print accuracy is something I didn't consider.  I'm willing to be a guinea pig, though!  To be honest I'm unlikely to interchange with anyone, and while a height gauge is simple enough to make out of various thicknesses of sheet styrene the simplicity of a height gauge block ready to drop on a coupler is attractive.

The only downside might be material cost...

[wcfn100]

Jason, print accuracy is something I didn't consider.  I'm willing to be a guinea pig, though!  To be honest I'm unlikely to interchange with anyone, and while a height gauge is simple enough to make out of various thicknesses of sheet styrene the simplicity of a height gauge block ready to drop on a coupler is attractive.

The only downside might be material cost...

I'll do it tonight and we'll see what the cost is.

Jason

[wcfn100]

Alright, I made a gauge.  It's available in Strong and Flexible and White Acrylic, the default being the latter due to better tolerances.  One side is the coupler and the other the top of the couper box.

https://www.shapeways.com/product/2QEFFA5WJ/beta-micro-trains-true-scale-coupler-gauge?key=bba886464d6e2d34b10fdee13edc02d5

This is just a test piece so use at your own interest.  I'll get one on order and check it against what I've been using and adjust accordingly.

Jason

[Ken Ford]

Thanks, Jason - let me know how the test prints, and I'll add one to my next order.

Edit - good, SW allowed me to add it to my existing order without additional shipping so it will come with your new draft gear.

[C855B]

Jason secreted me a couple of samples of his TSC conversion for the venerable Atlas 70-ton ore car. This model has been around since 1969, originally manufactured in the US and the molds either transferred to China, or re-tooled. Here's a comparison of the TSC versus the original issue:



Yes, the converted car also has MTL trucks, FVM wheels, Hay Bros. load, and Gold Medal brake wheel. It's amazing how much the perception of this car changes with minor detail work.

Two converted cars:



If you notice a difference in the draft gear pockets, that is only because the one on the left is painted.

For fun, comparing coupling distance over four generations:



From the top, original Rapido/US, stock Atlas/China, MTL short shank, and Jason's TSC conversions.

The conversion plate fits into the pocket which normally clears the truck-mounted coupler. Yes, it's attached with CA, but there is a lip against the back of the end sill, and it's not going anywhere. Conversion is easy, and went very fast after the first one. Good thing, I have about 100 more to do.   They fit all generations of the Atlas cars I have, and with a little trimming should also work on the Roco version.

Probably the most fiddly part of the process was the coupler modification. I used flush-cutters on the whiskers which left flat spots on the pivot rings, and had to file those down before it would fit in the pocket. The weld modification works great, and I am very pleased in the coupling action.

I made a couple of suggestions including maybe a mounting tab for the TSC air hose.

They run great, and look great. Thanks, Jason!

[wcfn100]

Thanks for the post Mike.  I'm was really glad to hear that the adapters works are they're supposed to.  I has occurred to me that you should check what the coupling distance should be for UP hoppers.  I did everything based on DMIR cars where the strikers are flush with the ends.

I know the coupler mods are a bit if a pain, but I'm hoping that those who purchased the regular boxes will be getting them soon and I can get some more feedback about their operation.  I think I could modify the coupler box a bit to be more forgiving with the clearances.  I agree the amount of filing needed is a bit much.  I just wouldn't want to include too much slop along the way.

I've already modified the lid to cover the gaps better.  I'll get a bunch printed out on my next order and we'll see how it works.  I'll also look into the mounting tabs to glue the air hose to.  I should be getting some long shank brown couplers this week and also my Shapeways order (if they ever print my coupler gauge) so I'll be working on this later this week.

One thing I forgot to ask earlier, how was drilling and tapping the FXD?  It's not ideal, but It looks like it won't be a problem.  What was your experience?


Thanks again.

Jason

[C855B]

I wouldn't worry about the UP version too much. The DM&IR car is a close foob for UP's jennies, but still a foob. Pictures of the UP cars are near impossible to find and I have found no shots of them in trains. Here's a builder's shot I've had for a while, apparently scanned out of a book or magazine, in the as-built brown:



The major difference is the ladders placed outside of the hopper frame. What little I can tell due to photo angle, the couplers are placed similarly, with the flush strikers. Anyway, either way I would not change what you have, it's a huge improvement.

Tapping the FXD was interesting. The first couple of times I felt like all I was doing with the tap was reaming a bigger hole. It turned out to not be a problem. What I did with the second pair was apply a little more downward pressure (instead of letting the tap lead) and backing out a couple of times to clear the shavings. No noticeable difference in the end result, but I felt better. The screws torqued firmly in all four. One thought - some commercial models have an 0- or 00-sized screw that's basically a wood-type thread with a countersunk #000 Phillips head. I haven't the foggiest where to get those screws, but they exist. They would eliminate the need to tap.

[Lemosteam]

IMHO, the biggest secret to tapping the FUD or FXD is running, by hand, the tap drill to ensure the hole is perfectly sized for the tap.