KEY drive I never knew existed

[up148]

Just saw this listing on EB and I never knew KEY offered a diesel with motors in each truck. Might be more prototypical but sure looks like a problem and it wasn't installed in any other of their diesels to my knowledge. Anyone know anything about this unique factory drive?

https://www.ebay.com/itm/284523822546?h ... SwNzVhi8D4

[E7]

Maybe a joint effort with Lionel....

2 gotta be better than one, right?

[GreggL]

I have a Key RS2 (started out as Pennsy IIRC) with those motors in each truck. Not the best drive <g>. Had Jay remotor it and convert to P:48.

...gregg

[up148]

I sure wondered Gregg. I've never seen any loco that ran well with truck motors, I think even trolleys and such are hit and miss, but I could be wrong about that one.

I believe I saw photos of your RS2 posted somewhere and Jay sent me a few photos to show me what my RC GP9 would look like under the hood. Nice running locos.

BTW, Jay must be busy, haven't seen any of his comments or posts for a while.

[bob turner]

About A quarter century ago I started putting a motor above each truck, so it would pivot above the bolster. Drop down was by Delrin chain. They worked quite well! Eliminated all U joints, and doubled the power. Only problem is the sprockets started cracking.

Also made all-wheel pickup for most, with spring-loaded brass plungers against the tread. Truly a hot setup.

Doesn't work well in narrow body units. But I still use two motors, with all the attendant U joints and rubber tubes.

[sarge]

I rebuilt and currently operate a Key NYC RS-3 with that drive; also have had a couple RS-2s through the shop. It’s a nice engine but certainly not a heavy-hitter. They were done back when Key was importing for modellers; before they got to be one of the craft-beers of O Scale. Grin!



I want to say their Alco roadswitchers in that era all came with a version of that drive, a Samhongsa thing if memory serves, and if I’m honest they have been smooth and reliable for me, though they are not heavy duty drives by any means in the classic old O Scaler sense of “My engines are filled with lead” and “I walk on my benchwork”. Grin!

I always think I’ll just build a conventional drive for them when I blow one up, but I’ve never blown one up so I (and many others) might be selling that drive short.

[up148]

Interesting info Sarge. I've only owned the KEY E & F units and they all use a tank drive system, which they never switched from, but it's much smoother and quieter than the old OMI tank drive, which was/is bad. I just never realized the RS's used this different drive.

Since I might get one in the future, will they pull a 10-12 car train?

Yes, I certainly remember the old phrase "why it'll pull the wallpaper off the wall", which never meant that much to me. Who has a layout large enough to need it anyway.

[sarge]

My layout is not large; an ops platform in a 13’x39’ space. 8-10 car trains are the norm and it has no issue. A previous layout in that space, the one I published in OST back in 2007, had a continuous run mainline with a max gradient of 2%. 10-12 cars didn’t bother the RS-2 I owned then.

Once you get past the unconventional layout, the Canon motor is small but of good quality and the gearboxes are full-size Samhongsa boxes, the same as in my Oriental C-420s.



Key RS-3 on the left, an Oriental C-420 on the right.

[sarge]

More grist for the mill.

A stock Weaver RS-3 weighs 2 pounds. A stock Weaver GP38 weighs 2lbs-6oz.

A Bultman RSD-12 weighs 4lbs-5oz, and a PSC RSD-5 4lbs even.

That Key RS-3 weighs 3-1/2 lbs in stock form.

So, the weight is well within range of what diesels of the era come in at, not a flyweight. The important thing is the drive in stock form easily has the power to slip the wheels when you hold on to the coupler. Easily.

[up148]

Sounds like a good drive. Plenty of power for normal operation and leaves the interior open for whatever.

[steamaheadstephen59]

Sarge A little of topic, I noticed that you use Peco track, this is a little unusual for American layouts. Its common here in Australia. I wondered If you have used there code 143 flat bottom flex track.

[De Bruin]

My .02, I have a Q-Car 45-toner center cab with the truck mounted magic carpet drives on both trucks that runs nicely (albeit it's small and light weight) and can pull somewhere around 6 old school metal trucked cars or 10 plus delrins. My issue with the truck mounted drives in general is you have to be careful and manage their consist load, mess that up and it ain't pretty. This is actually the killer with the old AHM HO drives in their O scale line too.

I should probably add that I had to "tune" the two drives to work with each other after one ground up the other which had to be replaced. I would be surprised if any of this applied to a Key product as they're usually the best in my experience.

[sarge]

Stephen

I’ve used the flatbottom, yes.

I use Peco points wired with microswitches to power the frogs; absolutely reliable and much better made than the current offerings from Atlas. I got that preference from my days in the UK and modelling 7mm both there and here.

I still enjoy building 7mm, but probably have to admit the original idea of switching to UK from US on this railroad as an optional operating scenario is becoming less and less likely as the structures are fleshing out.

I know there are other options, but I must admit handlaying is a deathmarch for me, the afore-mentioned ready-made US turnouts are pretty awful, and I’ve become quite spoilt by the consistency and reliability of Peco.

[steamaheadstephen59]

Thanks Sarge I think Peco make great track, I just wish they made a more American style track, maybe the flat bottom with slightly closer sleeper spacing, thou Its hard to tell when its ballisted.

[Erik C Lindgren]

Wasn't the purpose due to the prime mover detailing opening doors on the hood? Or was that different importer. Neat model.