TMCC and Legacy engine operating as a TR?

You have to have all engines in a MU/consist/lashup in the same operating mode. aka if you are trying to mix a Legacy engine and a TMCC engine in a consists they both have to be set to run in TMCC (aka 32 step mode). It doesn't really matter where the engines are located as long as you follow this guideline (page 61 of the v 1.3 manual). The lead engine does set the mode but you should have all engines running in the same mode anyway.

I read page 61 of V1.3 Legacy manual which states to put the Legacy engine in as the lead one and have it set as a TMCC engine in the info part of a cab-2. I did that and ran them with the Legacy in the front and you can hear and see the Legacy wheels spinning much faster than the TMCC odyseey engine. Same occurs with the Legacy as the rear unit.

I did read in the Legacy engine manual that in cab-1 mode but it pictures a cab-1 controller that odyseey speed control now offers selectable resolution and momentum as L=32, M=100, and H=100 with momentum. Can I do this with a cab-2 by placing the Legacy engine in cab-1 mode and then press the L button which will be 32 speed steps which is what a TMCC engine is capable?

Chuck- thank you for your initial reply here.

I don't think you can run any MU consistently in CAB-1 mode. CAB-1 mode uses relative speed steps. If you set the mode of a loco to CAB-1 mode you don't have a way to know what speed step a given unit is running at. TMCC mode uses absolute speed steps. I would suggest trying the set up with both loco's in TMCC mode. You can test the consist by placing the two loco's a few inches apart and try running them back and forth on a stretch of straight track. The should maintain the same distance. If they don't you may not be able to run the two units as MU's. BTW, did you set the stall speed on these engines before trying to create the MU?

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BTW, did you set the stall speed on these engines before trying to create the MU?

Chuck,
Did not think about this one as I originally thought you can run a Legacy engine directly behind a TMCC odyseey engine as the Legacy one will know it is running at 32 steps which the TMCC one does.

I will try what you suggested and try setting the stall.

how do u set the stall speed guys? Can't seem to find the directions in the manuals.

I have a similar problem. I am running two Legacy engines together under Cab1, and one engine runs slower than the other. If I put the faster engine in front, it ends up pulling the slower engine. If I put the slower engine in front, then the faster engine pushes it along until it derails.
That is why I am asking about stall speed. How do u set stall speed?

....you really can't "lashup" the two systems?

You have to make sure all of the engines in the consist are running in the same mode, aka TMCC. The stall speeds should be set/adjusted for each loco and then for the consist as well. This also means you can only do this using a Legacy base/CAB-2 as "modes" mean nothing for the CAB-1. It can only do relative speed steps.

Procedure for setting stall is outlined on this TMCC cheat sheet from the Rocky Mountain Division or the TCA:

Reference sheet for TMCC

Thanks for this information, Chuck. It's very interesting, and I'm glad this can be done. There was a small thread about this same general topic some months ago. At that time I was interested in running a Legacy SD-70 with a TMCC Dash 8, and the indication I got was that it wasn't possible to run these together.

It's been my understanding that when running two TMCC Odyssey 1 engines together, it is best to shut off the Odyssey on the rear engine. I thought the same would be true if running an Odyssey 1 engine with a Legacy (Odyssey 2) engine, but after seeing some responses on that old thread I was then led to believe the two engines were incompatible and couldn't be run together without a conflict no matter what.

I was surprised to hear this at the time - found it hard to believe that a Legacy engine wasn't backwards compatible to be able to run with a TMCC engine. Glad to hear that's not true.

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I was surprised to hear this at the time - found it hard to believe that a Legacy engine wasn't backwards compatible to be able to run with a TMCC engine. Glad to hear that's not true.

It is my understanding that you have to put the TMCC engine as the lead and the Legacy engine in the rear as it will sense or compensate for the 32 speed steps in a TMCC engine. But, I am going to set the stalls for each and for thr TR.

Tried setting each engine's stall and then tried setting the TR stall to no success. It seems you cannot put a Legacy and a TMCC engine together. I put the Legacy engine into the cab-2 as a TMCC engine as well.

Maybe Jon Z. will chime in with his thoughts.

Page 61 of the Legacy instructions says that legacy and tmcc engines can be used together. However the legacy engine must be set to tmcc under info. on the controller. The lead engine sets the operating system, so if its set to legacy it will run under legacy. It also says, for best results use alike engines tmcc/tmcc or legacy/legacy.

Did you try running the consist with about 2 inches of track separation to see if the locomotives even have the same gear ratios/performance properties? If the loco's can't maintain the two inch separation they can't be mu'd. Other factors that come into play are the number of axles (aka wheel base) and which drivers are blind and possibly the diameter of the wheels themselves.

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Did you try running the consist with about 2 inches of track separation to see if the locomotives even have the same gear ratios/performance properties?

My next step to try.

Both engines have 6 wheel trucks. Legacy Conrail U30C has flanged trucks with the design that the wheels will move somewhat freely on curves. TMCC engine-Conrail SD-80 has blind wheels on outside of 6 wheel truck.

Other remedy I am going to try is turning off Odyseey on both engines and having them both set as TMCC engines.

Ted,

chuck is 100% correct. First make sure the Legacy engine is in TMCC mode, so it runs with 32 speed steps. Set the momentum to low. Leave the Odyssey switch on. (You only turn off Odyssey if your consist, lash-up, whatever has an engine in it without Odyssey.) You don't need to set stall because stall was really designed for loco's with AC Pul-mor motors.

Next, put both engines on the track and connect them or put them close together. Set up the lash-up as per the Legacy instructions. The engines should run at close to the same speed. One will always run alittle faster than the other only becau of the differences inherent in the gearing and motor. It shouldn't be a dramatic difference but there will be a difference.

I had a TMCC BNSF Dash-9 (about 9 years old) and a Legacy UP SD70ace Running on my small layout for weeks with no problem. The Legacy loco was in the lead. Because I like the sound better. Oh yea, the TMCC engine didn't have Odyssey.

See the video below.

Mike R

https://www.youtube.com/watch?...youtube_gdata_player

Thanks all this is very good info.

thanks ALEX

So I am thinking of adding a 3759 to go with my older Santa Fe 3751 for a nice troop train. If I understand correctly I can run the Legacy engine out front and get all the legacy features (sounds) and the older engine will be fine and have regular TMCC sounds.

I'm sure I am wrong - but maybe not! Please Help!