Two RC/PF motors...

[andythenorth]

Fitting an extra RC motor to the green locomotive from Cargo Train Deluxe is a good move. Smoother, more consistent, doesn't spinout on points/flex track.

For the price of a motor and wire, this is a good performance boost. I'll try the same with a PF motor from 2010 Cargo Train when I have a spare one.

[jojo60]

Fitting an extra RC motor to the green locomotive from Cargo Train Deluxe is a good move. Smoother, more consistent, doesn't spinout on points/flex track.

For the price of a motor and wire, this is a good performance boost. I'll try the same with a PF motor from 2010 Cargo Train when I have a spare one.

I'm interested in a second PF motor for cargo train 7939. I wonder how to make de 2 motors run in the same direction : you have to make the power cable passing into the chassis hole in the middle of the the engine, so the motors will be inverted... is there a trick to revert one motor ?

Edited October 8, 2010 by jojo60

[dorfl]

I'm interested in a second PF motor for cargo train 7939. I wonder how to make de 2 motors run in the same direction : you have to make the power cable passing into the chassis hole in the middle of the the engine, so the motors will be inverted... is there a trick to revert one motor ?

I will try to connect it this way

PF motor ->PF<- PF Extension wire->9V<- PF Extension wire->PF IR receiver

but it needs a lot of space, the 9V connection have to be rotated by 90 degrees :)

[jojo60]

I will try to connect it this way

PF motor ->PF<- PF Extension wire->9V<- PF Extension wire->PF IR receiver

but it needs a lot of space, the 9V connection have to be rotated by 90 degrees :)

Good idea.

Maybe it would be a smaller solution to use the PF switch that can be found in set 8297 (I've got one spare...).

[Toastie]

Good idea.

Maybe it would be a smaller solution to use the PF switch that can be found in set 8297 (I've got one spare...).

Yeap, that should work fine.

If space is even more of an issue, you could use an RC train motor with 9V terminal (the one they sell at S&H, #8886), connect a short 9V cable to it, funnel that through and hook that up to a PF extension wire that goes to the receiver. The motor is not as strong as the PF motor (oh well, it may also be the o-rings) but for your purpose it should work well - at least it did for me.

Regards

Thorsten

[andythenorth]

...is there a trick to revert one motor ?

I hadn't thought of that It's not an issue for RC, but with PF it will be.

How about....crack open the case, rewire the motor, problem solved? Guess that's non-standard

[Brickviller]

Well it's not a real issue to add two motors to one train with Rc or PF. You only need a ploraity switch available from Lego.com. I've tried this to combine both PF and RC motors but they don't work good together (traction and power is different). So use only RC with Rc and PF with PF

[Toastie]

Well it's not a real issue to add two motors to one train with Rc or PF. You only need a ploraity switch available from Lego.com. I've tried this to combine both PF and RC motors but they don't work good together (traction and power is different). So use only RC with Rc and PF with PF

Well, I have heard that before and it may very well be!

But - have you checked on the performance of the rubber o-rings rather than blaming it on the motor itself? The old RC rings a crap - again as far as I am concerned - regarding grip. The "new" small train wheels run sort of uneasy - check #7938, just push the train over straight RC track and it is not smooth, as in the olden days. I guess what TLC has done is increasing the grip by using different o-rings. The old rings resulted in smooth track operation but lousy grip, the new ones have strong grip, but ... I have changed the o-rings from the PF to the RC motor and have run the mod with 9V motors - to be honest - I have a hard time in determining which motor is better or worse. Philo has done serious measurements on power consumption and tractive effort, but he did not change the hardware, at least as far as I know.

I just want to make sure we are talking about the same issue. And yes, the PF motor is performing better but again, maybe not entirely due to motor electrical power dissipation but wheel performance.

Regards,

Thorsten

[Snapshot]

I will try to connect it this way

PF motor ->PF<- PF Extension wire->9V<- PF Extension wire->PF IR receiver

but it needs a lot of space, the 9V connection have to be rotated by 90 degrees :)

That had better be 180 degrees or you'll probably short out the battery!

Jonathan

[Brickviller]

Well, I have heard that before and it may very well be!

But - have you checked on the performance of the rubber o-rings rather than blaming it on the motor itself? The old RC rings a crap - again as far as I am concerned - regarding grip. The "new" small train wheels run sort of uneasy - check #7938, just push the train over straight RC track and it is not smooth, as in the olden days. I guess what TLC has done is increasing the grip by using different o-rings. The old rings resulted in smooth track operation but lousy grip, the new ones have strong grip, but ... I have changed the o-rings from the PF to the RC motor and have run the mod with 9V motors - to be honest - I have a hard time in determining which motor is better or worse. Philo has done serious measurements on power consumption and tractive effort, but he did not change the hardware, at least as far as I know.

I just want to make sure we are talking about the same issue. And yes, the PF motor is performing better but again, maybe not entirely due to motor electrical power dissipation but wheel performance.

Regards,

Thorsten

I thought about that myself too. And used both the new kind of O rings on the train wheels. The result was already said

[dorfl]

That had better be 180 degrees or you'll probably short out the battery!

Jonathan

It works, but a lot of space needed. PF switch is better solution.

[andythenorth]

I'm thinking to just cut the PF wire to the motor and reconnect it with reversed polarity...modding electrical parts just doesn't seem like cheating to me

Edited October 9, 2010 by andythenorth

[Toastie]

I'm thinking to just cut the PF wire to the motor and reconnect it with reversed polarity...modding electrical parts just doesn't seem like cheating to me

I do well agree on that ...

Have fun, Thorsten

[StephanSz]

I was also wondering how to reverse the second motor and tested the following. Might help some of you out.

First motor is a PF motor connected to the IR receiver. Second motor is an RC motor with a reglar 9v wire connected to a 9v/PF extension wire which is connected to the IR receiver. You have to make sure that the ends of the 9v and extension wire are connected with the electical wires on the same side. Like on the images.

I'm pretty excited about this setup, it pulls my old 12v cars trough curves without a problem!

Edited October 10, 2010 by StephanSz

[DLuders]

There is another possibility for wiring up the Power Functions Battery Box to the RC motors: http://www.eurobricks.com/forum/index.php?showtopic=40200&st=0&p=710820entry710820 . You could modify the plug end and make it look a LOT better:

[pinioncorp]

StephanSz, that solves nothing as the PF motor is different to the RC motor. And while it would possibly add a little bit more tractive effort, I don't see the RC motor helping that much to pull that train. The two motors run at different speeds for the power they recieve, so that setup would actually strain both motors, causing damage.

The problem with the power functions motors is that you cannot easily reverse the polarity with the cables, like you could with the 9V connector type.

One way I've thought of is to just loop the wire of the second moror around the front of the locomotive. Unfortuntely it will remove the possibility for a coupler on the front, but if there is a hole in the front the cable is fairly long. Other than that cutting the cables might be my only option, there just isn't always space for a switch.

[Brickviller]

StephanSz, that solves nothing as the PF motor is different to the RC motor. And while it would possibly add a little bit more tractive effort, I don't see the RC motor helping that much to pull that train. The two motors run at different speeds for the power they recieve, so that setup would actually strain both motors, causing damage.

The problem with the power functions motors is that you cannot easily reverse the polarity with the cables, like you could with the 9V connector type.

One way I've thought of is to just loop the wire of the second moror around the front of the locomotive. Unfortuntely it will remove the possibility for a coupler on the front, but if there is a hole in the front the cable is fairly long. Other than that cutting the cables might be my only option, there just isn't always space for a switch.

Again I need to say this. It can all* be solved with this: http://shop.lego.com/ByTheme/Product.aspx?p=8869&cn=587&d=70

* With all I mean the problem with the second PF motor going backward instead of forward like the other motor

[DLuders]

Yes, Brickviller is correct -- the Lego 8869 Power Functions Pole Reverser Switch is what you need:

Mark Bellis has this picture showing how everything is wired (from this Eurobricks post):

[StephanSz]

StephanSz, that solves nothing as the PF motor is different to the RC motor. And while it would possibly add a little bit more tractive effort, I don't see the RC motor helping that much to pull that train. The two motors run at different speeds for the power they recieve, so that setup would actually strain both motors, causing damage.

Well, it might not be the optimal solution, it does make a huge difference. So much that I'm going to get another PF motor and a PF switch to reverse it :-)

[Zerobricks]

What about just rotating one drive motor 180 degrees, so you dont need a switch?

[peterab]

What about just rotating one drive motor 180 degrees, so you dont need a switch?

That is the obvious first idea, the problem with that is the wire from the motor must pass around the bogie pin to get to the hole in the baseplate. It gets caught up and can cause derailment or snagging on track. It is much more reliable to have both wires toward the center.

Even if it did work you would probably need an extension wire anyway, so you don't save much.

Edited October 11, 2010 by peterab

[ZueriHB]

It works, but a lot of space needed. PF switch is better solution.

This would also work, and uses less space.

[mpec82]

Uhm, a bit confused. If I would like to add a second RC motor to my 7898, i need something else apart another RC motor and the relative wire? How do i have to connect the second motor?

[Snapshot]

Uhm, a bit confused. If I would like to add a second RC motor to my 7898, i need something else apart another RC motor and the relative wire? How do i have to connect the second motor?

No, you just need the motor and wire for RC. It's PF that gives the problems as the connectors cannot be reversed to reverse the direction of the second motor.

[mpec82]

No, you just need the motor and wire for RC. It's PF that gives the problems as the connectors cannot be reversed to reverse the direction of the second motor.

So i simply connect this way?

FM= front motro

FL= front light

RM= rear motor

RL= rear light