Can I power my train with the parts that I've got?

[L@go]

Hi there. I've got some questions that have probably been answered somewhere before, but I don't really know where to start looking for the answers, so if any of you would be so kind as to enlighten (ooh, nasty word) me, I'd very much appreciate it.

I recently bought Anthony Sava's Polar Express instructions, and they call for two motors to power the tender. Being stupid as I am, I started buying the parts I thought I needed without doing the proper research, and it could only end badly: I now realize that the parts I've bought probably don't go together very well.

First I bought two 8866 sets, with what I now understand are RC motors. It never occurred to me that these motors might not be up to date with what else Lego offers these days, as I bough them in the Lego store in London from an employee who seemed to know what he was talking about (they didn't have 88002 in stock, and he said I could just as well use 8866 with extension cables).

Then I bought an infrared PF receiver, two extension cables and a rechargeable battery box.

All you experienced train builders are probably right now thinking 'what a schmuck. Everybody knows that won't work.'

But I didn't know! :)

So, here's my question: Is there any way to combine the PF receiver, the battery box and the RC motors? Or do I have to get replacements for some of the central components (probably the motors, then)?

I'd appreciate any feedback.

[Pingles]

I am not familiar with the instructions well enough to know what motors are called for.

But what you have described is a working combination! Congrats!

The only thing I see missing is the remote controller itself.

[L@go]

Got it! I didn't realize that the light bluish gray connector bricks did have connecting points underneath.

And I've got the remote controller, so that's no problem.

So now everything works. But this leads me to another issue.

The two motors have to be mounted facing in different directions underneath the tender, because the buffer beams sit on the opposite side of the connecting points on the motors (if you understand what I mean), like this:

This means that if I connect both motors to the same connecting point on the IR receiver, they pull in separate directions, which needless to say is not very practical. The alternative is to connect one motor to each of the IR receiver's two connecting points, but then I have to control both motors separately, which is also highly impractical.

So, the next question must be: Is it possible to get one of the motors to spin in the other direction?

EDIT: Added picture.

Edited July 19, 2011 by L@go

[Daedalus304]

The best way I know of is to use LEGO's polarity switch on just one of the motors.

You can find it here on S@H.

Just use it to set one of the motors in reverse.

[Snapshot]

Got it! I didn't realize that the light bluish gray connector bricks did have connecting points underneath.

And I've got the remote controller, so that's no problem.

So now everything works. But this leads me to another issue.

The two motors have to be mounted facing in different directions underneath the tender, because the buffer beams sit on the opposite side of the connecting points on the motors (if you understand what I mean), like this:

This means that if I connect both motors to the same connecting point on the IR receiver, they pull in separate directions, which needless to say is not very practical. The alternative is to connect one motor to each of the IR receiver's two connecting points, but then I have to control both motors separately, which is also highly impractical.

So, the next question must be: Is it possible to get one of the motors to spin in the other direction?

EDIT: Added picture.

You can use the reversing switch, as mentioned or pick up a couple of short 9V cables from the 'bay or Bricklink. You attach one to each motor but connect the other ends in the opposite direction to each other i.e. a cable sticking out each end. Then connect one of your extension cables from the IR controller to the stacked connectors. An old solution to a common problem.

The problem you might also find with using the PF connectors straight onto the 8866 motors is that they're slightly too thick for the bogies to turn easily when used with standard train baseplates. The 9V cable connectors are slightly thinner so avoid the problem.

Jonathan

Edited July 20, 2011 by Snapshot

[L@go]

Thank you so much for your clarifying answers.

I've just placed an order for a reversing switch - I'm going with that option because I can get it relatively cheap without having to go for used pieces, and I can still use all the pieces that I've already got. As the tender is eight wide it's not built on a regular train base, so it's no problem that the connectors make the motors a tiny bit taller.

Again, thanks! I really look forward to see this thing go around a train loop all by itself, it's beautiful - and HUGE. Have a look here for Anthony Sava's own pictures. I chose to go all-out and have built the loco, the tender and all three cars.

[RockeTeK]

So, the next question must be: Is it possible to get one of the motors to spin in the other direction?

You don't need anything else to get this to work.

If I am correct, you should simply change the position of one of the two small black switches on the controller.

8879: http://shop.lego.com/en-NL/LEGO-Power-Functions-IR-Speed-Remote-Control-8879?c=Train-Accessories-Trains-ByTheme

8885: http://shop.lego.com/en-NL/LEGO-Power-Functions-IR-Remote-Control-8885?c=Power-Functions-ByTheme

[Snapshot]

You don't need anything else to get this to work.

If I am correct, you should simply change the position of one of the two small black switches on the controller.

8879: http://shop.lego.com/en-NL/LEGO-Power-Functions-IR-Speed-Remote-Control-8879?c=Train-Accessories-Trains-ByTheme

8885: http://shop.lego.com/en-NL/LEGO-Power-Functions-IR-Remote-Control-8885?c=Power-Functions-ByTheme

You're not correct. Both motors are connected to the same channel so using the switches will alter both of them.

[RockeTeK]

You're not correct. Both motors are connected to the same channel so using the switches will alter both of them.

Ah yes, then you would need an extra receiver...

[L@go]

Ah yes, then you would need an extra receiver...

...which is quite a lot more expensive than the reversing switch!

[Pingles]

Snipping the wires on one of the power cords and reversing them would likely work as well. Cheap little modification if you like dinking around with that kinda stuff.

[SavaTheAggie]

The reversing switch is a life saver. Unfortunately on several of my builds I've have had such little room left over that installing the switch caused it to switch into the opposite position. :)

You shouldn't have that problem with the Berkshire, its' tender is quite roomy. Good luck!

Snipping the wires on one of the power cords and reversing them would likely work as well. Cheap little modification if you like dinking around with that kinda stuff.

You have to be careful there - the PF system uses four wires, and you have to be sure that you're swapping the correct ones. Two of the wires are direct power, and two of the wires are signaled power. I'm no expert, but I think the motors receive power from two of the wires when powered directly from a battery box, and the other two wires when getting power directly from the IR receiver.

--Tony

Edited July 23, 2011 by SavaTheAggie

[Toastie]

You have to be careful there - the PF system uses four wires, and you have to be sure that you're swapping the correct ones.

Hi Tony and L@GO,

that is right and real quick: The 2 "outer" cables are +9V and 0V or ground. The inner two are called C1 and C2. All "dumb" devices like motors and lights get power from C1/C2. All devices requiring permanent power (e.g., receivers) do get that via 9V/0V and "forward" power via C1/C2 to motors/lights, mostly PWM modulated. You may want to look up Philo's PF reference page.

So when you want to reverse the motor direction you need to "cross" the inner two (C1/C2) wires.

Best regards,

Thorsten

Edited July 23, 2011 by Toastie

[Pingles]

Thanks Toastie and Sava! Gonna have to note that for myself somewhere!

[L@go]

Thanks Toastie and Sava! Gonna have to note that for myself somewhere!

So I guess something came out of this post that was useful not just to me. Nice!

You shouldn't have that problem with the Berkshire, its' tender is quite roomy. Good luck!

I know - I've already tried it out and ordered the pieces necessary for the (slight) modification. Going to have to flip the battery box onto its side, though, as the connector on top of it makes it just that tiny bit too tall.

Great design, by the way - like all the others I've bought from you. If I'm not mistaken I now own four trains of your design.