Coupling two PF powered locomotives

[Hobbes]

OK, so I want to give this PF system a chance.

I have two PF motorized locomotives that I would like to run independently but also coupled. How do I go about that? The question basically is how the PF motor fares if it is pulled and doesn't run on its own (i.e. the motor of the second locomotive).

1. Set both receivers/motors to the same channel? Can't run them independently anymore without taking the locomotive apart and change the channel. Not feasible.

2. Set each to its own channel. Can run them independently, but how does the second motor hold up? Does it even matter? Do I have to run both motors? Not very comfortable controlling two motors for the same train.

3. Power only one locomotive and pull the second. Yeah, right.

Proves that 12V is still the best, where I can control this with signals and a decoupler...

Any ideas?

Thx in advance.

[AndyC]

1) Design the engine so that the channel can be changed easily, either directly or indirectly (much as the new trains allow you to turn the battery on/off)

2) Use an M/XL motor and provide a manual switch to disengage the gearing, so it can be pulled easily.

3) Use an M/XL motor and build a gearbox that engages/disengages dependent on direction, trading "reverse" for the ability to pull the locomotive backwards without friction

4) Design a new coupling such that motor power is fed along the train through the couplings then feed the wheels a combination of the motor power and coupling power through differentials, which should average things out and provide constant speed.

5) Do something far cleverer than the few ideas I've thought up in about 5 minutes, show it on Eurobricks and win the respect of millions!

[JopieK]

OK, so I want to give this PF system a chance.

I have two PF motorized locomotives that I would like to run independently but also coupled. How do I go about that? The question basically is how the PF motor fares if it is pulled and doesn't run on its own (i.e. the motor of the second locomotive).

1. Set both receivers/motors to the same channel? Can't run them independently anymore without taking the locomotive apart and change the channel. Not feasible.

2. Set each to its own channel. Can run them independently, but how does the second motor hold up? Does it even matter? Do I have to run both motors? Not very comfortable controlling two motors for the same train.

3. Power only one locomotive and pull the second. Yeah, right.

Proves that 12V is still the best, where I can control this with signals and a decoupler...

Any ideas?

Thx in advance.

Well, I have made some implementations for PF with Arduino. You could add extra remote control options of course, just extend the protocol :) I agree that the 12V features like the points remote control and signals were never met with any other system, but PF gives some opportunities for that if you have some knowledge of embedded systems.

[Duq]

Pulling a non-powered motor will not work. The train wheels have rubber rings so either you're dragging rubber along the tracks or you're trying to drive the motor from the wheels. Either way it's going to take a lot out of the performance of the working motor.

As suggested above you could modify the design of your trains to make it easy to change the channel. Another option is to have them on the same channel but have one on the blue control and one on the red. Then link the control wheels on the controller (with gears or a chain) so you can control the two outputs on one channel together.

It's still no guarantee that the motors will run at the same speed because of the way the controller works; it's not sending "speed 4" but it's sending "speed +1" or "speed -1". If one of the motors misses one of the commands they'll be out of sync until the train is stopped (or until the other motor misses a command).

[Seany]

I've had the same thoughts before and after some messing around found that controlling the two engines isnt too bad, put one on Red and the other Blue and move the controls together. A bit fiddly at first but you get used to it.

The other option of just dragging the other engine isnt too bad, it depends how heavy they are, the lighter engines like on the 7938 Passenger Train will quite happily be dragged along without any complaints. The middleweights like the 7939 Cargo Train are fine as long as the ride isnt too bumpy and you dont change speed too quickly otherwise they decouple. And the heavyweights like the EN just wont have it, although you can effectively use the second loco for power and shove the front loco, just try not to reverse.

The magnets on the PF loco's are quite strong, with two 7939's set to travel in the oposite direction they will sit there spinning their wheels for the first few power settings, whereas the magnets from my 7898 RC Cargo Train give up quite quickly.

[JopieK]

Pulling a non-powered motor will not work. The train wheels have rubber rings so either you're dragging rubber along the tracks or you're trying to drive the motor from the wheels. Either way it's going to take a lot out of the performance of the working motor.

As suggested above you could modify the design of your trains to make it easy to change the channel. Another option is to have them on the same channel but have one on the blue control and one on the red. Then link the control wheels on the controller (with gears or a chain) so you can control the two outputs on one channel together.

It's still no guarantee that the motors will run at the same speed because of the way the controller works; it's not sending "speed 4" but it's sending "speed +1" or "speed -1". If one of the motors misses one of the commands they'll be out of sync until the train is stopped (or until the other motor misses a command).

Wel that is partially true, it depends on the controller as well! The technic controller gives an other command than the train controller. The implemented it a bit lousy is my opinion (at least that is what I would say if some student of mine would have done it like this ;)).

[hoeij]

OK, so I want to give this PF system a chance.

I have two PF motorized locomotives that I would like to run independently but also coupled. How do I go about that?

It doesn't take much time to take the motor off and replace it by unmotorized wheels.

[henryhotspurs]

Two powered motors require synchronization to pull the consist? Sounds pretty authentic to me! I have much the same setup and love fiddling with the engines to get the speed synched. Kinda fun actually.

Additionally, I have learned to detach one engine from another by using the remotes to power the engines away from each other. Entering my yard I stop the train, remotely pull the header engine off, back it unto a siding where I grab another set of cars, then run two trains without ever having to touch either one.

There are lots of games you can play with the two engines on seperate channels.

[jaster]

3. Power only one locomotive and pull the second. Yeah, right.

What exactly is wrong with this? If you build the dummy locomotive light enough and powered locomotive strong enough it would work well. You could easily have a six axle locomotive and not worry about designing powered trucks.

[mostlytechnic]

I've been playing around with using my PF-powered Emerald Night and my loco from the 7939 Cargo Train together. Add a ton of cars and they can pull about anything. I use the speed control remote and have the two set to separate channels so I can control individually. I've found that with them both on, they handle any speed variation just fine. Sometimes if I'm way off, one engine or the other will spin wheels, but usually it "just works"