More AZL curiosities...

[DKS]

I was really curious how AZL came up with their easier-coupling "Auto-Latch" couplers. How did they do it?

The original "hard-coupling" AZL design has a small pin molded onto the side of the knuckle. This pin keeps the two coupler parts from spreading.

The new easier-to-couple "Auto-Latch" couplers are the old couplers with this pin removed.

Which means... yes, you can convert the original "hard-coupling" AZL couplers into new easier-to-couple "Auto-Latch" couplers by simply clipping off this pin.

Go figure...

(In fairness, it apears that they did do some new tooling; the awful flash is gone from the older couplers. Also, one of the contributing factors to their hard coupling was that the sprue entered the knuckle face, and clipping the knuckle off the sprue left an uneven surface--vaguely similar to the machining flaw in M-T couplers--but that's a whole 'nuther story...)

EDIT: Do not cut the pin off the old couplers. They do indeed couple more easily, but they are then prone to uncoupling.

[bambuko]

Well, depending on the tool design and the number of cavities, they may have produced new inserts.
This would have taken care of mods and the horrible flash.
That qualifies as new tooling even if the mould is still the same  ;D

[DKS]

Well, depending on the tool design and the number of cavities, they may have produced new inserts.
This would have taken care of mods and the horrible flash.
That qualifies as new tooling even if the mould is still the same  ;D

The parting line on the older style runs right through the center of the knuckle. On the newer ones, the parting line runs along the bottom of the knuckle. So, I'd say that constitutes all-new tooling...

Also... correction about the trick of cutting off the pin to make the older ones easier to couple... they also come uncoupled more easily as a result. I suspect that this is why they made the new "Auto-Latch" couplers very nearly rigid in the coupler pocket, with virtually no side-to-side play. The older ones moved side-to-side with relative ease.

[Sokramiketes]

I found it interesting that the knuckle wasn't connected to the coupler shaft, rather the thumb was, on the AZL couplers on my SD75i.  One is able to pull the knuckle right out of the assembly...  Usually the knuckle is connected to the shaft to take the pulling force, whereas the thumb doesn't carry load, just keeps things coupled together. 

The AZL coupler does stay together when pulling the 20 something cars I have on hand, just curious what its limit is.

[DKS]

I found it interesting that the knuckle wasn't connected to the coupler shaft, rather the thumb was, on the AZL couplers on my SD75i.  One is able to pull the knuckle right out of the assembly...  Usually the knuckle is connected to the shaft to take the pulling force, whereas the thumb doesn't carry load, just keeps things coupled together. 

The AZL coupler does stay together when pulling the 20 something cars I have on hand, just curious what its limit is.

Curious. On both truck-mounted coupler designs, the coupler shaft is split. Having just opened both coupler pockets, I was presented with two totally different internal designs (yes, all-new tooling throughout, including the pocket and lid). On the old design, the thumb wraps round a hollow pivot tube (much like an M-T), while the knuckle has a dimple that engages a hole in the thumb' shaft, and also has centering springs. On the new design, both coupler parts are identical, wrapping around the pivot (which is much smaller) and having centering springs.

EDIT: A photo really helps explain things. Old, top; new, bottom.

[Sokramiketes]

I found it interesting that the knuckle wasn't connected to the coupler shaft, rather the thumb was, on the AZL couplers on my SD75i.  One is able to pull the knuckle right out of the assembly...  Usually the knuckle is connected to the shaft to take the pulling force, whereas the thumb doesn't carry load, just keeps things coupled together. 

The AZL coupler does stay together when pulling the 20 something cars I have on hand, just curious what its limit is.

Curious. On both truck-mounted coupler designs, the coupler shaft is split. Having just opened both coupler pockets, I was presented with two totally different internal designs (yes, all-new tooling throughout, including the pocket and lid). On the old design, the thumb wraps round a hollow pivot tube (much like an M-T), while the knuckle has a dimple that engages a hole in the thumb' shaft, and also has centering springs. On the new design, both coupler parts are identical, wrapping around the pivot (which is much smaller) and having centering springs.

Ah, this sounds much better.  I should have explained it as not attaching to the centering pin and misspoke about not connecting to the "shaft" but you covered the potential flaw.  50+ car trains were mentioned in the Trainbored thread, so that must be a result of the new design.  Looking forward to the rest of your review.

EDIT: With the photo, looks much better too!

[Sokramiketes]

Don't forget to address that unsightly gap in the MTL coupler knuckle that sticks out in this angle...

[bambuko]

thanks David,
very good photos and also explains some comments about AZL new couplers not swinging much from side to side? ie remaining more firmly centred