Exactrail has a new Draft Box coming

[DKS]

The #1015, #1016 and #2004 have the coupler spring in front of the pivot post.  These three couplers are generally the ones used in OEM products, as opposed to the original #1023 coupler.  BLMA, ESM, FVM, IMRC, TWX, WOT and now EXR are using the #1015 or #1016 components in their integrated coupler boxes, and the Bluford coal hoppers are designed to substitute in the #1015 knuckles.  The #1015 also is the coupler being used on the newer body-mounted MTL models (hoppers and heavyweights), and the #2004 is what is used on the MTL cabooses.

Thanks for the clarification. It's been so long since I've bought new M-T couplers that I hadn't realized they've made so many changes.

[ednadolski]

Um, no, the standard configuration of an MT coupler is such that the spring is on the other side of the fulcrum, away from the coupler knuckle. MT has been known to tinker with their own design, and there are variations, but that is not the standard configuration. This is:

Just a $0.02, but with this design I don't see how it's really possible to eliminate the pogo, as long as there is a spring to absorb/release energy and the coupler is free to move longitudinally.  Switching the side of the fulcrum just changes direction, i.e. pushing vs. pulling, or uphill vs. downhill.

I suppose some level of cancellation could be achieved by having a car with an inboard spring on one end and an outboard spring on the other, but that likely would be hard to balance because of small manufacturing tolerances, and there also could possibly be resonances at various load levels.

Ed

[SkipGear]

I just realized how simple it is to get rid of the slink. I have to draw something up and send it to Joe..... HMMM.....not sure why I or somebody else didn't think of this before.

[bbussey]

Just a $0.02, but with this design I don't see how it's really possible to eliminate the pogo, as long as there is a spring to absorb/release energy and the coupler is free to move longitudinally.  Switching the side of the fulcrum just changes direction, i.e. pushing vs. pulling, or uphill vs. downhill.

True.  Moving the spring to the other side doesn't remove the oscillation.  But it becomes less prevalent due to the fact that forward movement is the dominant action of a freight consist.  It can get tricky if switching cars using the delayed uncoupling feature though, whereas with the #1023 there is no oscillation while pushing.

[ednadolski]

it becomes less prevalent due to the fact that forward movement is the dominant action of a freight consist.

Right, tho there are cases too such as pushers and/or mid-train helpers where there will often be some parts of the train that are in tension while some other parts of the train are in compression.  Then the grade changes from up to down and all the forces reverse direction.  So for me at least, the partial solution is a pretty limited one at best.

Ed

[ednadolski]

I just realized how simple it is to get rid of the slink. I have to draw something up and send it to Joe..... HMMM.....not sure why I or somebody else didn't think of this before.

Not too sure what you have in mind, but I'm pretty curious.   You'd have to retain the centering action somehow, and a certain amount of play so that the coupler will still operate.   I recall trying things like adding a small rod inside the spring, or replacing the spring with a small strip of foam, but they never worked well enough.  Maybe something like two springs, one on each side of the fulcrum, but that's new tooling and I don't know if the forces would balance out well enough.

Ed

[SkipGear]

My idea requires new tooling but the coupler would fit in the same or smaller space and still have the soft coupling that an accumate doesn't. It really depends on if the right spring could be made.

[Blazeman]

The contributors here never cease to amaze me with their insight on mechanical, electrical, and computer aspects of this hobby. And done in a rational manner as well.

[inkaneer]

But what about the coupler?   Doesn't it seem to extend out to far????

[bbussey]

The #1016 coupler is correct for simulating the coupler shaft of the prototype.  The BLMA version also utilizes the #1016 coupler.

[inkaneer]

The #1016 coupler is correct for simulating the coupler shaft of the prototype.  The BLMA version also utilizes the #1016 coupler.

I realize these had an extended coupler but this one appears to extend 4-5 feet.  What is the prototype coupling distance?

[Ed Kapuscinski]

These three couplers are generally the ones used in OEM products, as opposed to the original #1023 coupler.

It's a shame too, because the 1015 pocket design sucks when it comes to ride height. That's the reason the body mounted FVM cars ride HIGHER than their truck mounted predecessors.

[Craig Martyn]

The #1016 coupler is correct for simulating the coupler shaft of the prototype.  The BLMA version also utilizes the #1016 coupler.

Incorrect.  The prototype does have an extended coupler, but the #1015 sticks out so far from it's bolster point, it actually measures out correctly for the 64' Reefers.  That said, a 1016 in that coupler pocket does stick out way too far.  Our Reefer uses the 1015 coupler.

(Little back-end story that few know about:  We had shipped 1016 couplers to our factory and our ENTIRE Reefer production was fitted with the 1016 couplers (we sold a LOT of these cars - thank you all).  Upon receiving our production samples, we noted our mistake - the 1016 was ridiculously too long.  So, even after being boxed for shipment, every car was unpacked, 1016 couplers removed and 1015 added.  Long story short, this cost us considerable time and money, but our commitment to quality stands and we just couldn't release the cars with the wrong coupler...)

[lock4244]

A miniature hydraulic cushioning device will solve the slinky effect.

[ednadolski]

A miniature hydraulic cushioning device will solve the slinky effect.

I think you have to eliminate the energy storage/transfer.   Anything with a spring will always resonate under the right loading/friction conditions.

Ed