Lash up - Legacy with an TMCC engine

They do have to have the same gear ratio plus the Legacy engine has to be set for TMCC.

Pete

Ray,

Absolutely.  If they won't run at about the same speed when they're not coupled together, say with a few inches between them, they also won't run nicely together when coupled.

Mike

Pete,

Thanks for the info. I did reset the Legacy engine (E8) to TMCC and it still will not run at the same speed as the TMCC engine. I even tried to run the E8, still set to TMCC with another TMCC engine, same results.

When I rest the E8 to Legacy and did a lash up with another Legacy engine, SD40, they ran great.

So I wonder if Legacy engines, even if reset to TMCC, wont work in a lash up with other TMCC engines.

Your thoughts?

RAY

I know many will, with the same gear ratio. A lot of early TMCC diesels had direct gear drive, motor to axle. Sometime on the later 2000s Lionel switched to Liondrive which have a ball end on the motor that fits into a coupling. Those engines including most all Legacy engines have this Liondrive. That might explain the different gear ratios.

I have run TMCC and the early Legacy NYC Mohawks together no problem but they do have have the same gearboxes.

Most if not all of the the LionDrive diesels have back-driveable gears, like Postwar Lionel.  This means that the wheels can turn the motor (but don't force it!)  If your Legacy model is back-driveable, a minor difference in speed isn't a big deal.  It's better to put the faster unit in the lead.

I have been hawking O-gauge train gear ratios for years.  As far as I know, all Lionel, MTH, Atlas, Weaver diesels with two vertical motors have gear ratios around 10.5:1 and they all use Mabuchi RS-385PH can motors.  If there were any major changes I would love to know!

Given how many LionDrive motors I've found with the drive nub loose, I wouldn't be abusing the drive by running dissimilar speeds.

@gunrunnerjohn posted:

Given how many LionDrive motors I've found with the drive nub loose, I wouldn't be abusing the drive by running dissimilar speeds.

I think the drive nubs come loose because people try to pull stumps. Or,  a loco loses the command signal and suddenly accelerates from zero to 18 volts, pulling about 10 g's in the process.  Perhaps the owner restrains it with his hand it to prevent a high-speed wreck.  If they didn't have traction tires, the wheels would spin in all of these scenarios, and the nubs wouldn't slip on the shaft ;-)

That being said, I love the back-driveable gears.  I also like the idea that all of the motors are interchangeable without having to pull and press the worm gear.  I do agree with you that Lionel's implementation is a bit light-duty.

The best approach is to run both locos near each other, but not coupled together.  If the difference in speed is less than 10%, I think the O.P. would be ok with the faster loco in the lead.

I always test my MU configurations uncoupled first.  For sure if I was doing TMCC/Legacy I'd do extra testing.  I did note that my full Legacy upgrade of an MTH Premier F59PH engine runs exactly with my other stock Lionel Legacy engines, so the gear ratios must indeed be the same.  I'm using a standard Legacy encoder and flywheel on the MTH motor.

@Ted S posted:

I think the drive nubs come loose because people try to pull stumps. Or,  a loco loses the command signal and suddenly accelerates from zero to 18 volts, pulling about 10 g's in the process. 

Or maybe because people try "back driving" the gears.

The gears are designed to be "back driven" to a point.  For example, if the two motors don't start or run at exactly the same speed (this was one of the causes of the infamous Odyssey Lurch.)  And specifically, when the locos are in a "lashup" with other locos which might or might not be back-driveable.

I don't advocate trying to turn the wheels by hand, that's why I said in my initial post, "don't force it!"

I've seen a lot of folks, kids and older hobbyists, try to push a loco down the tracks.  Bad idea.  In other scales without rubber tires, this wouldn't be a big deal.  With postwar or MPC-era trains that have free-rolling gear trains and all-metal wheels, no big deal.   But with modern era trains, at a minimum you could stretch the tires leading to their premature replacement, and in a worst case scenario you'll strip a gear.

I recall from some time ago the advice that when running two engines MUed, to turn off the Odyssey on one of the engines (assuming, for a TMCC engine, it has the Odyssey on/off switch). Is this advice valid, and if so does it only apply when both engines are TMCC?

If the speed control is disabled (or not installed) on the TMCC engine, I have found success in lashing up with Legacy or other TMCC.  Most likely, the Legacy unit with speed control will have to push faster or slow down the speed control-less TMCC engine, but baring the extremes, this is not a problem.  Of course, it is a trial and error to see what will work with different combinations of engines and different speed steps.  But with the speed control off, the two engines won't be actively fighting each other.

For me, I lash up Atlas O GP60m and B40-8w units with the speed control off with Legacy SD40s and 45s all the time without issues.

@Catonsville Central Railway posted:

If the speed control is disabled (or not installed) on the TMCC engine, I have found success in lashing up with Legacy or other TMCC.  Most likely, the Legacy unit with speed control will have to push faster or slow down the speed control-less TMCC engine, but baring the extremes, this is not a problem.  Of course, it is a trial and error to see what will work with different combinations of engines and different speed steps.  But with the speed control off, the two engines won't be actively fighting each other.

For me, I lash up Atlas O GP60m and B40-8w units with the speed control off with Legacy SD40s and 45s all the time without issues.

Thanks for the information, Woody. Very helpful.

Found this video from Lionel. It talks about tmcc but not sure how legacy would play into it. I thought I also remember that tmcc had 32 speed steps and Legacy have 200 steps. I think you may have to build it as a tmcc train. Hope this helps

https://m.youtube.com/watch?v=l3HmEZ_qw5Y