Legacy Locomotives not going the same speed

I assume you are running them as a train lash-up.  It could be corrupted data.  For each individual engine reset and reenter the engine ID's and make sure the engine info is the same for both (press info on the cab 2).  Delete the current train lash-up and rebuild the train.  If the situation remains the same reverse the engines in the train build to see if that helps.  

Are both engines the exact same model and road number?  Are they early modular or do they have an RCMC board?

Good luck! 

Bruce

Jim, those that will help you will need the item number. There may he be a history.

Rod, it is 6-81170 and 6-82207. They are they same model, same tooling, no changes. I just found that the 507 is missing a drive gear in the truck. Would this cause a speed difference?

I had this issue with the first run of heritage UP SD70's and the second run. The later run locomotive would break away and the speed steps did not match. When I sent it in it was returned stating they were geared differently and the steps were different. Disappointing. 

Surefire posted:

I had this issue with the first run of heritage UP SD70's and the second run. The later run locomotive would break away and the speed steps did not match. When I sent it in it was returned stating they were geared differently and the steps were different. Disappointing. 

Thats odd. Checking the parts list for both engines their trucks have the same part numbers. Being Liondrive, all the gearing is on the truck. The motor has no gear mounted to it.

Since they both have RCMCs any difference would be in the programming which should be the same. It sounds more like a programming issue which can be corrected.

Pete

Are these being compared in a MU (lashup) or ran independently?

If independently, make sure that the momentum settings are the same.  Train brake settings are the same, off being optimum.  Odyssey is on both engines.

When they are in a MU, the front engine, I believe, will run ever so slightly faster.  This is in the programming per JonZ.

MartyE posted:

Are these being compared in a MU (lashup) or ran independently?

If independently, make sure that the momentum settings are the same.  Train brake settings are the same, off being optimum.  Odyssey is on both engines.

When they are in a MU, the front engine, I believe, will run ever so slightly faster.  This is in the programming per JonZ.

The locos are MU’ed. Here is the pics of the trucks

You are definitely missing a gear.  I'd get that replaced and see what happens. 

If you run them about 2 inches apart in non MU (lashup) mode, how do they track?

That's a new one, a missing gear!

Reminiscent of my new F40ph with the missing grooves for the traction tires, they used the wrong wheels!

Since the missing gear is affecting wheels not driven with the traction tire, I don't know if it'll make a significant difference, but it's certainly not right.

MartyE posted:

You are definitely missing a gear.  I'd get that replaced and see what happens. 

If you run them about 2 inches apart in non MU (lashup) mode, how do they track?

If I run them apart in a lash-up the 513 accelerates away from 507(the one missing the gear). Its strong enough to pull the electro-coupler open when they are hooked together. Also the 507 has trouble getting going with a train over 6 o27 boxcars and it flashes the cab light signaling a motor error. It works fine after I give it a little push, I'm guessing that it is a motor problem. Any thoughts?

Well, the fact that that one is missing the gear already suggests it needs a closer look.

I wonder if the motor and/or truck is binding and that's why it's having so much trouble.  I think I'd be inclined to pop the top and see what is really going on inside.  You will also certainly need a new truck, I don't believe you can just get the individual gears.

gunrunnerjohn posted:

Well, the fact that that one is missing the gear already suggests it needs a closer look.

I wonder if the motor and/or truck is binding and that's why it's having so much trouble.  I think I'd be inclined to pop the top and see what is really going on inside.  You will also certainly need a new truck, I don't believe you can just get the individual gears.

Yes, I have to get a new truck. I took the shell off and found out that the rear motor is the problem. It won’t spin in forward motion with out a push. It may be lack of power? The trucks roll freely off the engine.

gunrunnerjohn posted:

That's a new one, a missing gear!

Reminiscent of my new F40ph with the missing grooves for the traction tires, they used the wrong wheels!

Since the missing gear is affecting wheels not driven with the traction tire, I don't know if it'll make a significant difference, but it's certainly not right.

A long time ago, I purchased a Red Caboose GP9; a lovely model which ran (and still runs) very well. At any rate, early on I pulled of the gear covers, just to check for lube and to make sure I didn't have split gears (something these Roco-built engines are known for).

No split gears, but I realized that (1) of the (4) axles was missing a gear: not split, or chipped...just had a smooth axle. 

Mark in Oregon

At slow speeds the motor without encoder ring may not spin.  This is normal.  Try a higher speed step, and both motors should have decent torque.  If you have the modular board set, then some variation in speed is normal.  Still they should cooperate well enough in a lash-up. 

The newer RCMC will have close speed matching if both locos have that electronics package.  If they don't match up, it is possible one of the locos has a bad encoder (the encoders have dual sensors) and this can affect speed if one of the two sensors is bad.

As a rule, all Legacy locos should speed match, per design.  Try running them on the same ID as an engine and post the results here...

You're getting it from the "horses' mouth" here.   FWIW, I have seen what Jon talks about with almost every cruise equipped dual motor locomotive.  When I'm working on them on the rollers, the encoder equipped motor will be moving and more often than not at low speeds, the second motor just sits there.  A simple test you can do, just grab the flywheel of the sensor equipped motor lightly, you'll see the other motor take off when the cruise pours on the coals to keep the speed up.